NAGARAJA T, M.Sc. (Agri.) I.D. No

Transcription

1 BIOEFFICACY AND HARVEST TIME RESIDUE OF CARBOSULFAN 6G ON RICE AND ITS EFFECT ON SUCCEEDING CROP (BLACK GRAM) Thesis submitted in partial fulfilment of the requirements for the degree of DOCTOR Of PHILOSOPHY IN AGRICULTURAL ENTOMOLOGY to the Tamil Nadu Agricultural University, Coimbatore By NAGARAJA T, M.Sc. (Agri.) I.D. No DEPARTMENT OF AGRICULTURAL ENTOMOLOGY CENTRE FOR PLANT PROTECTION STUDIES TAMIL NADU AGRICULTURAL UNIVERSITY COIMBATORE

2 BIOEFFICACY AND HARVEST TIME RESIDUE OF CARBOSULFAN 6G ON RICE AND ITS EFFECT ON SUCCEEDING CROP (BLACK GRAM) By NAGARAJA. T., M.Sc. (Agri.) I.D. No DEPARTMENT OF AGRICULTURAL ENTOMOLOGY CENTRE FOR PLANT PROTECTION STUDIES TAMIL NADU AGRICULTURAL UNIVERSITY COIMBATORE

3 CERTIFICATE This is to certify that the thesis entitled " BIOEFFICACY AND HARVEST TIME RESIDUE OF CARBOSULFAN 6G ON RICE AND ITS EFFECT ON SUCCEEDING CROP (BLACK GRAM)" submitted in partial fulfilment of the requirements for the award of the degree of DOCTOR OF PHILOSOPHY (AGRICULTURE) IN AGRICULTURAL ENTOMOLOGY to the Tamil Nadu Agricultural University, Coimbatore is a record of bonafide research work carried out by Mr. NAGARAJA. T., under my supervision and guidance and that no part of this thesis has been submitted for the award of any other degree, diploma, fellowship or other similar titles. However, part of the thesis work has been published in peer reviewed scientific journal of national/ international repute (copy enclosed). Place: Coimbatore Date : Dr. M. GANESH KUMAR (Chairman) Approved by Chairman : (Dr. M. GANESH KUMAR) Members : (Dr. S. KUTTALAM) (Dr. S. ROBIN) (Dr. R. JAYAKUMAR) (Dr. S.V. KRISHNAMOORTHY) Date: (EXTERNAL EXAMINER)

4 ACKNOWLEDGEMENT With whole heartedness I bow my head before God the Almighty for his unspeakable help through various hands which helped me, pursue the endeavor to completion. And so comes the time to look back on the path traversed during the Endeavour and to remember the faces behind the action with a sense of gratitude. Nothing of significance can be accomplished without the acts of assistance, words of encouragement and gestures of helpfulness from others. I wish to record my deep sense of gratitude and thanks to my Chairman Dr. M. Ganesh Kumar, Professor, Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore for his expert guidance, excellent suggestions, inestimable help, sustained encouragement and constructive criticisms evinced all throughout the study period. I feel very much privileged by getting an opportunity to work under his guidance. My truthful and heartfelt thanks eternally remain with him. I accol with gratitude the valuable suggestions and guidance by Dr.S. Kuttalam, professor & Head Department of Entomology, Dr. S. V. Krishnamoorthy, Professor & Head Department of Sericulture, Dr. S. Robin Professor & Head, Dept of Department of Rice, and Dr. R. Jayakumar, Professor of soil science as members of Advisory Committee for their encouragement, guidance valuable suggestions and support rendered during the tenure of the study. I profusely thank Dr. M. R. Sreenivas, Dr. P. Kalyanasundaram, Dr, Mutturaman, Dr. K. Ramaraju, Dr. S. Suresh, Professor, Department of Agricultural Entomology and PG Coordinator, Dr. S. Sridharan, Department of Agricultural Entomology for their timely help as and when needed during the course of study. I express my thanks with pleasure to my classmates, Sengutuan, Boopathi, Baskarn, Dhachina, and Sampthkumar for their care, timely and untiring help and support.

5 As, dearest is the friends love who have volunteered help at the time of need for achieving my cherished goal and made life in TNAU memorable paves me to offer loveable and debited thanks to Vignesh, Praveen, Vijay, and my juniors. My heartfelt thanks to my all time dearest and nearest people for their mellifluous love, care, timely help, encouragement and support which was the pillar that supported my thesis work. I remember with deepest gratitude those special persons who were with me during my low times and constantly encouraged me to complete my work. I extend my thanks to the Miss. Kusuma, (SADH) and Miss. Sujatha (ADH) Bio Tecnlogical center, Hulimavu, Bangalore, Department of Horticulture Government of Karnataka for providing all sorts of help to carry out the Residue Analysis. I am in loss of words to express my heartfelt gratitude and indebtedness to my parents, Shri. Thimmappa D. and Smt. Gangamma and my dearest sister Jayamma T. Who showered on me lots of love and affection, extreme care, whole hearted prayers and encouraging words which is incomparable that makes to step up in my life. I acknowledge Sree Kumaran Computers, TNAU campus, who rendered valuable service for the preparation of thesis in a perfect way. I am grateful to all humble hearts that helped me directly and indirectly during the study period. I gratefully submit my special ardency and deep sense of gratitude for all others, who had helped me knowingly or unknowingly wherever they are, goes my thanks with the assurance that their assistance not be forgotten. (Nagaraja T.)

6 Dedicated to My beloved parents

7 ABSTRACT BIOEFFICACY AND HARVEST TIME RESIDUE OF CARBOSULFAN 6G (NS) ON RICE AND ITS EFFECT ON SUCCEEDING CROP (BLACK GRAM) By NAGARAJA T. Degree : DOCTOR OF PHILOSOPHY AGRICULTURE) IN AGRICULTURAL ENTOMOLOGY Chairaman : Dr. M. GANESH KUMAR Professor of Agricultural Entomology Tamil Nadu Agricultural University Coimbatore Studies were conducted in rice to evaluate the bioefficacy of carbosulfan 6G (NS) insecticide against Scirpophaga incertulas (Walker), Cnaphalocrocis medinalis (Guenee), Nephotettix sp. Nilaparvata lugens (stal), Sogatella furcifera (Horvath)., safety to non target organisms viz., Spiders, Cyrtorhinus lividipennis Reuter., Paederus fuscipes (Curtis). phytotoxicity, acute toxicity, harvest time residues in rice and its effect on succeeding crop (Black gram) and arthropod biodiversity in rice ecosystem. Field experiments conducted with carbosulfan 6G (NS) at 1250 and 1000 g a.i.ha - 1 was superior in reducing the yellow stem borer damage which was in the range of per cent in first season and per cent in second season. Application of carbosulfan 6G (NS) at 1250 and 1000 g a.i.ha -1 effected per cent reduction of leaf folder to the extent of and in first and second season respectively and of green leaf hopper to the extent of in the second season. Carbosulfan 6G (NS) at 1250 and 1000 g a.i.ha -1 effected maximum per cent reduction of BPH and WBPH population in first and second seasons respectively. The order of efficacy of different treatments is as follows; carbosulfan 6G (NS)

8 1250 g a.i. ha -1 > carbosulfan 6G (NS) 1000 g a.i. ha -1 > carbosulfan 6G (NS) 750 g a.i. ha -1 > carbosulfan 6G (ES) 1000 g a.i. ha -1 > carbosulfan 6G (ES) 600 g a.i. ha -1 > phorate 10G 1000 g a.i. ha -1 against rice pests. Carbosulfan 6G (NS) at 750 and 600 g a.i.ha -1 was less toxic to spiders, mirids and rove beetles. Carbosulfan 6G (NS) at 750 g a.i.ha -1 recorded yield of 5856 and 5415 kg ha -1 in first and second seasons respectively and was on par with the higher test doses viz., 1250 and 1000 g a.i.ha -1. Carbosulfan 6G (NS) at test doses of 1000 and 2000 g a.i.ha -1 (x and 2x doses) did not cause any phytotoxicity symptoms on rice and the succeeding crop (black gram). The safety evaluation of carbosulfan 6G against the two species of earthworms revaled that the LC 50 of carbosulfan to Eudrilus eugeniae (Kinberg) and Perionyx exacavatus (Perrier) was very high and the LC 50 values of carbosulfan 6G to the fresh water common carp Cyprinus carpio L. and Cirrhinus mrigala. by static method were 125 and 133 ppm, respectively. The harvest time residues of carbosulfan 6G applied at 1000 and 2000 g a.i.ha -1 were at below detectable level (BDL) in rice grain, straw, husk, bran and soil at first and second season harvests. The succeeding crop (black gram) also had below detectable level (BDL) in seeds, husk and soil in first and second season harvests. The arthropod biodiversity study was conducted with special reference to collection and identification of arthropods, their abundance, species richness, dominance and evenness indices and beta diversity richness of the habitat was explored. The arthropods existing in the rice ecosystem have revealed a wide array of 5,001 individuals under 118 species, 65 families and 11 orders from two classes viz., Insecta (4019) and Arachnida (982). Among the Pterygota (4,019), majority of the individuals belonged to the division Endopterygota (2,164) with maximum number of individuals from Coleoptera (1,000) followed by Hymenoptera (595), Lepidoptera (290) and Diptera (279). The Exopterygota (1,855) were represented by six orders viz., Hemiptera (1,201), Thysanoptera (230), Orthoptera (210), Odonata (181), Dictyoptera (22), and Dermaptera (11). Under the class

9 Arachnida, Araneae (982) was the common order. Totally, nine families of Araneae were collected with the majority of individuals belonging to Araneidae (243) Salticidae (176), Lycosidae (147), Tetragnathidae (97) and Oxyopidae (75), In rice ecosystem, there existed a greatest species richness and increased arthropod abundance in terms of total numbers, species richness indices (species number, Fisher alpha index, Q statistic, Shannon Weiner index and Brillouin index), dominance indices (Simpson s index, Berger-Parker index and McIntosh index) and evenness indices (Equitability J). In case of species distribution in rice ecosystem, scattered distribution of individuals was observed in ordinal level pattern while in familial and species level, the distribution of individuals was more or less uniform in the entire ecosystem studied. Beta diversity analysis based on ordinal, familial and species levels was highest in unsprayed field in case of Whittaker Bw, Cody Bc, Wilson and Shmida Bt, Routledge Br, Routledge Bi and Routledge Be. Dendrogram analysis on Araneae family showed that Salticidae and Lycosidae were closely related in rice. The family level cluster analysis under the order Hemiptera, revealed Alydidae and Delphacidae as the most closely related families. Regarding Hymenoptera, the families Trichogrammatidae, Ichneumonidae and Apidae were closely related. Among Coleoptera, Bruchidae and Buprestidae were closely related families in rice ecosystem.

10 CONTENTS CHAPTER NO. TITLE PAGE NO. I II III IV V VI INTRODUCTION REVIEW OF LITERATURE MATERIALS AND METHODS RESULTS DISCUSSION SUMMARY REFERENCES

11 Table No LIST OF TABLES Title Effect of carbosulfan 6G on damage caused by stem borer in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on damage caused by stem borer in rice (Location: PBS, TNAU, Coimbatore II season) Effec t of carbosulfan 6G on damage caused by leaf folder in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on damage caused by leaf folder in rice (Location: PBS, TNAU, Coimbatore II season) Effect of carbosulfan 6G on population of GLH in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on population of GLH in rice (Location: PBS, TNAU, Coimbatore II season) Effect of carbosulfan 6G on population of BPH in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on population of BPH in rice (Location: PBS, TNAU, Coimbatore II season) Effect of carbosulfan 6G on population of WBPH in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on population of WBPH in rice (Location: PBS, TNAU, Coimbatore II season) Effect of carbosulfan 6G on population of spiders in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on population of spiders in rice (Location: PBS, TNAU, Coimbatore II season) Effect of carbosulfan 6G on population of mirids in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on population of mirids in rice (Location: PBS, TNAU, Coimbatore I season) Effect of carbosulfan 6G on population of rove beetle in rice (Location: PBS, TNAU, Coimbatore I season) Page No

12 Table No. 16. Title Effect of carbosulfan 6G on population of rove beetle in rice (Location: PBS, TNAU, Coimbatore II season) 17. Yield Particulars of Rice during first season Yield Particulars of Rice during second season Yield Particulars of black gram during first season Yield Particulars of black gram during second season Phytotoxicity symptoms of carbosulfan 6G on rice - Season I Phytotoxicity symptoms of carbosulfan 6G on rice - Season II Phytotoxicity symptoms of carbosulfan 6G on succeeding crop (black gram) - Season I Phytotoxicity symptoms of carbosulfan 6G on succeeding crop (black gram) - Season II 25. Acute toxicity of carbosulfan 6G to earthworms Acute toxicity of carbosulfan 6G to fishes Recovery studies of Carbosulfan 6G (NS) in rice grain, husk, bran, straw and soil-first season Recovery studies of Carbosulfan 6G (NS) in rice grain, husk, bran, straw and soil-second season Recovery studies of Carbosulfan 6G (NS) in succeeding crop (black gram)-first season Recovery studies of Carbosulfan 6G (NS) in succeeding crop (black gram)-second season Harvest time residue of carbosulfan 6G in rice, straw, husk, bran and soil Harvest time residues of carbosulfan 6G (NS and ES) in succeeding crop (black gram) Diversity of arthropods at familial and generic level in rice ecosystem Page No Diversity of arthropods at ordinal level in rice ecosystem 108

13 Table No. Title Page No. 35. Diversity of arthropods at familial and generic level in rice ecosystem Diversity of arthropods at familial, generic and species level in rice ecosystem (Class: Arachnida) Diversity of arthropods at familial, generic and species level in rice ecosystem (Sub class: Exopterygota) Diversity of arthropods at familial, generic and species level in rice ecosystem (Sub class: Endopterygota) Arthropod diversity in rice ecosystem Alpha diversity (Species number) Arthropod diversity in rice ecosystem Alpha diversity (Fishers alpha) Arthropod diversity in rice ecosystem Alpha diversity (Margalef s D) Arthropod diversity in rice ecosystem Alpha diversity (Q Statistic) Arthropod diversity in rice ecosystem Alpha diversity (Brillouin diversity index) Arthropod diversity in rice ecosystem Alpha diversity (Shannon- Weiner index) Arthropod diversity in rice ecosystem Alpha diversity (Simpson s index) Arthropod diversity in rice ecosystem Alpha diversity (McIntosh index) Arthropod diversity in rice ecosystem Alpha diversity (Berger Parker diversity index) Arthropod diversity in rice ecosystem Alpha diversity (Equitability J) Arthropod diversity in rice ecosystem Beta diversity Values of similarities recorded between families of Araneae in rose using Bray-curtis per cent similarity Values of similarities recorded between families of Hemiptera in rose using Bray-curtis per cent similarity Values of similarities recorded between families of Coleoptera in rose using Bray-curtis per cent similarity Values of similarities recorded between families of Hymenoptera in rose using Bray-curtis per cent similarity 163

14 LIST OF FIGURES Figure No. Title Page No. 1. Efficacy of Carbosulfan 6G (NS) on the per cent damage of stem borer and leaf folder in rice Season I 2. Efficacy of Carbosulfan 6G (NS) on the per cent damage of stem borer and leaf folder in rice Season II 3. Efficacy of Carbosulfan 6G (NS) on the per cent damage of stem borer and leaf folder in rice Season I 4. Efficacy of Carbosulfan 6G (NS) on the population of GLH, BPH and WBPH, in rice Season II Effect of Carbosulfan 6G (NS) on rice yield Effect of Carbosulfan 6G (NS) on black gram yield Dendrogram showing the similarity of families of Araneae collected from rice ecosystem based on Bray-curtis per cent similarity 8. Dendrogram showing the similarity of families of Coleoptera collected from rice ecosystem based on Bray-curtis per cent similarity 9. Dendrogram showing the similarity of families of Hemiptera collected from rice ecosystem based on Bray-curtis per cent similarity 10. Dendrogram showing the similarity of families of Hymenoptera collected from rice ecosystem based on Bray-curtis per cent similarity

15 Plate No. LIST OF PLATES Title 1. Field experiment on rice I Season TNAU, Coimbatore Field experiment on rice II Season TNAU, Coimbatore Field experiment on Succeeding crop (Black gram) Carbosulfan application activities on rice pest management Acute toxicity of Carbosulfan 6G to fishes Acute toxicity of Carbosulfan 6G to earthworms Sampling techniques 50 Page No. 8. Arthropods observed in Rice ecosystem (Order: Araneae) Arthropods observed in Rice ecosystem (Order: Araneae) Arthropods observed in Rice ecosystem (Order: Araneae) Arthropods observed in Rice ecosystem (Order: Araneae) Arthropods observed in rice ecosystems (Order: Hemiptera) Arthropods observed in rice ecosystems (Order: Hemiptera) Arthropods observed in rice ecosystems (Order: Hemiptera) Arthropods observed in rice ecosystems (Fabricius) (Leptocorisa oratorius 16. Arthropods observed in rice ecosystems (Order: Orthoptera) Arthropods observed in rice ecosystems (Order: Odonata) Arthropods observed in rice ecosystems (Order: Coleoptera) Arthropods observed in rice ecosystems (Order: Coleoptera) Arthropods observed in rice ecosystems (Order: Diptera and Coleoptera) Arthropods observed in Rice ecosystem Scirpophaga incertulus (Walker) Arthropods observed in Rice ecosystem Cnaphalocrocis medinalis (Guenee) 23. Arthropods observed in rice ecosystems (Order: Hymenoptera) Arthropods observed in rice ecosystems (Order: Hymenoptera) Arthropods observed in rice ecosystems (Order: Hymenoptera)

16 ABBREVIATIONS a.i. BDL CIB cm DAA DAT DMRT EC ES ha hl l LC 50 LD 50 mg NS ppm RBD SL WP Active ingredient Below detectable limit Central Insecticide Board Centimetre Days after application Days after transplanting Duncan s Multiple Range Test Emulsified concentration Existing source Hectare Hectare litre Litre Median lethal concentration Median lethal dose Milligram New Source Parts per million Randomised Block Design Soluble Liquid Wettable powder % Per cent

17 CHAPTER I INTRODUCTION Rice, Oryza sativa L. is a staple food crop grown mainly in Asian countries like China, India, Japan, Korea, Srilanka, Pakistan, Bangladesh, Indonesia, Malaysia, The Philippines, Thailand etc. More than 90 per cent of rice is produced and consumed in these Asian countries. Rice is biologically, ethologically and culturally bound with the life of Asians. The total rice growing area in the world is million hectares with a production of 618 million tons of rough rice. Among the rice producing countries, India occupies number one position with regard to area with 44.3 million hectares followed by China (29.3 million ha.). However, with regard to the productivity or per hectare yield of rice, India occupies fifteenth or still lower position with 3.01 t./ha of rough rice, compared to China (6.26t./ha.), Japan (6.65 t./ha.), Korea Republic (6.57 t./ha.), Indonesia (4.57 t./ ha.), Malaysia (3.36 t./ha.),the Philippines (3.65 t/ha.), Srilanka (3.51 t./ha.) etc. (FAO,2006). The major reasons for low productivity in India are the losses due to insect pests, diseases and weeds. About 300 species of insects have been reported to attack rice crop in India, out of which, 20 have been found to be the major pests, causing 21 to 51 percent yield loss. It provides 27 per cent of dietary energy and 20 per cent of dietary protein in the developing world. The crop is cultivated in at least 114, mostly developing countries and is the primary source of income and employment for more than 100 million households in Asia and Africa (FAO, 2005). China and India together account for more than half of world s rice area and, along with Indonesia consume more than three- fourth of the global rice production (Hossain, 1997; MacLean et al., 2002). In recent years, concern over food security is increasingly sensed, more in developing countries where rice production did not match the increasing population. Focus sharpened as prices soared steep leading to widespread fear of hunger followed by riots and violence in Export of rice was curtailed or suspended by some of the Third World s leading producers (Cotula et al. 2009). With reduced land availability and increased demand for enhanced production, attention is turned towards intensification through higher fertilizer inputs and cropping. Such efforts, in turn increased pest intensities (Heong, 1996) and losses caused by pests has

18 remained an important constraint in achieving high rice yields (Waddington et al., 2010). Given that the world s population is expected to reach nine billion by 2045 (US Census Bureau, 2009), the importance of reducing losses from pests gains greater focus. Only species out of nearly 800 insect pest species recorded on rice, are major pests in tropical Asia. Of the several management options available, by and large, only pesticides still dominate and serve as the primary component. The largest proportion of the world rice pesticide market is in insecticides. In 1993, an estimated US $1,114 million or 37 per cent of the total was spent on insecticides for rice (Woodburn, 1993). Of this, a large portion was in Japan (34%), India (22 %), China (11%) and Korea (10%) (Kiritani et al., 1979). The world population is expected to reach 9.1 billion by the year 2050 with the current annual growth rate of 1.2 per cent and the tropical regions of the world will be mostly accounted for this trend (UN, 2001; Cohen, 2005; UN, 2005). Increasing food productivity for food security is very essential in many tropical countries (FAO, 2005) and one direct consequence of the booming food production is the threat to natural ecosystems. The situation is especially alarming in tropical ecosystems because biodiversity is higher temperate regions (Lacher and Goldstein, 1997). Tropical ecosystems, although a relatively small fraction of the land surface of the earth (26%), hold a very high primary productivity (Deshmukh, 1986). Sustainability of such systems is directly linked to attainment of equilibrium between human needs such as agricultural production and environmental damage. Some decades ago, Chang (1968) stressed the importance of deliberate planning in maintaining such a balance, which is still lacking in tropical ecosystems. A significant proportion of the world s biodiversity is recorded in agroecosystems (Pimentel et al, 1992). The increasing use of agrochemicals in such systems affects non-target organisms in soil and water (Abdullah et al, 1997; Reinecke and Reinecke, 2007) and is often a major factor contributing to declining biodiversity (Barr, 1993; Chamberlain et al, 2000; Robinson and Sutherland 2002; Benton et al, 2003; Bianchi et al, 2006). Nevertheless agricultural production is directly linked with the number and quantity of agrochemicals used (Klassen, 1995; Matson et al, 1997; Carvalho, 2006), illustrating the trade-off between food production and biodiversity.

19 The rice ecosystem has been contaminated with environmentally incompatible poisonous pesticides. Due to these constraints, the research for developing alternative economical and ecofriendly method of insect control is needed. It is certain that the domestication of rice ranks as one of the most important developments in history. This grain has fed more people over a longer period of time than has any other crop. As this quote illustrates, rice is a particularly key crop for humans. For example, rice provides 25 to 85 per cent of the calories in the daily diet of 2.7 billion Asians. This makes it the number one staple food crop on this planet. It is also worth noting that, unlike other major cultivated grains like wheat and maize (corn) which are also used for feeding livestock, rice is used mainly for human consumption. From time to time, several insecticides have been tried and recommended for successful management of rice pests. Farmers give top priority to chemical control because of certain inherent advantages in pesticides. More than 70 per cent of the farmers in India are rural based with low rate of literacy. Farmers are more convinced with chemical control due to rapid remedial action against the target pest and control and less convinced with other means of control (Regupathy and Ayyasamy, 2009) Carbosulfan (Marshal ) 25 EC is one of the broad-spectrum insecticides developed by FMC Corporation for the management of sucking and chewing pests in agriculture and public health. Carbosulfan 6G, 25 EC and 25 DS formulations proved to be effective as broadcasting, foliar spray and seed dresser respectively against many insect pests on okra, chillies, rice, maize, beans, apple, cotton, brinjal, citrus and cauliflower (Mote and Shah, 1993a; Chandrasekaran et al., 1994; Rao and Panwar, 1995; Asaf Ali and Chinniah, 1999; Ahmed et al., 2000; Karthikeyan and Purushothaman, 2000; Lei Hue De et al., 2000; Sontakke and Dash, 2000; Singh, et al., 2001; Srinivasan and Rabindra, 2001; Sheeba Jasmine, 2002). In recent times, agrochemical companies focused their research on biorational or reduced risk insecticides. These are synthetic or natural compounds that effectively control insect pests, but have low toxicity to non target organisms (humans, animals and natural enemies) and environment (Hara, 2000). Today there is great demand for safer and more selective insecticides affecting specifically harmful pests (Kirshnamoorthy et al., 2009)

20 The pest management strategy being adopted mainly depends on use of the pesticides, though attempts are made to reduce the use of pesticide for obvious reasons. In India, about one fifth (17-18%) of the pesticides usage in agriculture is on rice (Kapadia and Mohla, 1980). An array of insecticides is used for the control of various pests of rice (Regupathy et al., 1999).Carbsosulfan 6G also gives more protection against rice pests (Hugar et al., 2009). Seed treatment is rapidily becoming a standard agricultural practice. Seed treatment is not a new method of insect control as David and Gardner (1954) pointed out that the method was thought of as early as 50 AD by Junius collumella. Smaller amounts are supposed to work more effectively and selectively just eliminating the pest and not harming the useful insects. The pest ingests the chemical compound that is deadly for them with the plant juices. On the contrary, the natural enemies which are beneficial in checking the insect pests remain unharmed. Seed treatment with Carbamates viz., carbofuran, aldicarb sulfone (Regupathy and Subramaniam, 1982; Regupathy, 1981) and carbosulfan (Chinnaiah and Asaf ali, 1999) have been reported. Recently newer insecticides chloronicotinyle group viz., imidacloprid (Regupathy et al, 1999; Surulivelu et al., 2000), acetamiprid (Kumar et al., 1999), thiacloprid and thiamethaoxam (Scarpellini and Nakamura, 1999) have been introduced which are effective at very lower dosage and relatively safe. In the event of changing the technical material sourcing of the carbosulfan, it is mandatory on the part of CIB (Central Insecticide Board) guidelines to generate data on the bioefficacy, phytotoxicity, residues, safety to the natural enemies and soil flora and fauna in the rice ecosystem for the new formulation of carbosulfan 6G. Keeping in mind the situations referred above the present study was undertaken with the fallowing objectives.

21 1. To evaluate the bio-efficacy of carbosulfan 6G (NS) against rice pests viz., stem borer, leaf folder, green leafhopper, brown planthopper and white backed planthopper. 2. To study the phytotoxicity and its safety to natural enemies in rice ecosystem. 3. To determine the residues of carbosulfan 6G (NS) on rice (grain, straw, husk, bran and soil) and its effect on succeeding crop (black gram) using HPLC. 4. To assess the impact of carbosulfan 6G (NS) on arthropod biodiversity in rice ecosystem.

22 CHAPTER II REVIEW OF LITERATURE The literature pertaining to bioefficacy of carbosulfan 6G against stem borer, leaf folder and sucking pests, impact on natural enemies, phytotoxic effect and their residues and biodiversity in rice ecosystem are collected and presented in this chapter Mode of action of carbosulfan Carbosulfan is a low toxic derivative from carbofuran and it was first described in the year It is a broad spectrum insecticide, nematicide, acaricide, effective against insects and mites with stomach and contact action. It is a systemic insecticide having bioactivation with a LD50 value of 3820 mg/kg; ADI value of which is Carbosulfan is an acetylcholine esterase inhibitor. It must be transformed to carbofuran in order to become an active cholinesterase inhibitor. This conversion does not occur in vertebrates which confers significantly low mammalian toxicity. The metabolism of carbosulfan, 2, 3-dihydro-2, 2-dimethyl-7-benzofuranyl (di-n-butylaminosulfenyl) (methyl) carbamate, in Valencia orange tree leaves, mature and immature fruits was investigated using [ring- 14 C] - and [dibutylamino- 14 C] carbosulfan. Carbosulfan was metabolized to carbofuran (2, 2-dimethyl-2, 3-dihydrobenzofuran-7-yl methylcarbamate) and dibutylamine by a first order reaction. The half-life of carbosulfan in the leaves and mature fruit was about four days. No translocation of radioactivity from leaves to mature oranges was detected and a trace (0.1 ppm or less) of the applied radioactivity was observed in the edible portion of the mature orange treated with the ring-labelled material (Clay and Fukuto, 1984) Bioefficacy of insecticides against insect pests of rice Stem borer Dhaliwal and Jaswanth Singh (1986) found that phosphamidon 85 WSC, monocrotophos 36 WSC and chlorpyriphos kg a.i ha -1 provided effective control against stem borer. Pandya et al., (1987a) reported that aqueous 0.04 per cent

23 solution of monocrotophos 36 WSC was most effective in killing neonate larvae of yellow stem borer (68.9%) followed by fenitriothion 50 EC (65.9%) and chlorpyriphos 20 EC (63.1%). Sukhija et al., (1988) found that among granular insecticides, cartap hydrochloride was the most effective with 3.8 per cent white ears. Application of carbosulfan 3G at 1 kg a.i. ha -1 followed by monocrotophos 0.5 kg a.i. ha -1 gave effective protection against yellow stem borer and recorded minimum incidence of 2.35 to 4.13 per cent dead heart than all other treatments (Singh 1996). Singh and Sarao (2000) found that lambda cyhalothrin at 12.5 g a.i ha -1 was more promising with per cent white ear damage and 4750 kg ha -1 grain yield. Jena (2001) reported that seedling root dip with 0.02 per cent emulsion of chlorpyriphos was the best in controlling yellow stem borer infestation at initial stages of crop growth. Flubendiamide at 25 and 50 g a.i. ha -1 recorded low level of dead heart (0.81 and 0.53%) and white ears (1.26 and 1.24%) compared to other treatments and the highest yield was recorded in plots treated with flubendiamide 50 g a.i. ha -1 (6230 kg ha -1 ) (Gowda.2005). Among the different treatments, cartap hydrochloride 750 g a.i. ha -1 and fenpropathrin 100 g a.i ha -1 were the best in reducing stem borer damage (Patil, 2005) Leaf folder Leaf folder incidence was effectively controlled by triazophos (Nandarajan and Skaria 1988) while the plants applied with synthetic pyrethroids recorded per cent leaf damage. Among the tested insecticides, phosphamidon 85 WSC, quinalphos 25 EC and monocrotophos 36 WSC were on par and resulted in 88.9 per cent mortality of eggs followed by fenthion (88.4%). Among pyrethroids, cypermethrin with 91.1 per cent reduction in damage was the most effective followed by fenvalerate (90.5%), deltamethrin (90.2%) and permethrin (90.2%) were on par with each other (Raju et al., 1990).

24 Profenofos and chlorpyriphos at 500 g a.i. ha -1 were the most effective treatments in reducing the leaf folder damage and increased grain yield by 32.3 and 46.9 per cent, respectively (Singh and Singh, 1999). Karthikeyan and Purushothaman (2000) reported that profenofos at 375 g a.i. ha -1 recorded significantly lesser leaf folder damage (0.35 and 2.97 at 27 and 57 DAT, respectively). Verma and Guptha (2001) reported that quinalphos 25 EC and monocrotophos 36 WSC effectively reduced the population of leaf folder up to and per cent respectively and consequently increased yield of rice and q ha -1, respectively at 250 ml ha -1 compared to untreated control. Lambda cyhalothrin was found to be effective based on reduced leaf damage and increased yield at 250 g a.i. ha -1 (Rao et al., 2002). Flubendiamide 20 WDG at 12.5, 25 and 50 g a.i. ha -1 was found effective in reducing the leaf folder damage and stem borer at all the doses tested (Gowda and Naik, 2005). Benfuracarb g a.i. ha -1 gave satisfactory control of rice pest complex along with significant increase in yield (Dhar et al., 2009) Green leafhopper (GLH) Nephotettix virescens (Distant) Kalode et al. (1970) reported that foliar spray of monocrotophos and chlorpyriphos were effective against green leafhopper adults. Dahipale et al. (1979) reported 70 per cent reduction in leafhopper population when a mixture of urea and phosphamidon were applied. Lakshmanan et al. (1985) recommended a mixture of one per cent urea and phosphamidon 85 EC (320 ml ha -1 ) at 20 and 35 days after transplanting for effective control of GLH. Velusamy and Subramanian (1987) reported that phosphamidon at 210 g a.i ha -1 effectively controlled GLH population. Macatula et al. (1987) reported that 0.75 g a.i. ha -1 gave good control of GLH. Organophosphorous insecticides such as phosphamidon, monocrotophos and chlorpyriphos were successfully used for the control of GLH, brown planthopper and white backed planthopper (Rao and Rao, 1984). However, monocrotophos and phosphamidon at 0.05 per cent were less effective in controlling GLH (Krishnaiah and Ghosh, 1988).

25 Krishnaiah and Kalode (1988) observed that, the synthetic pyrethroids deltamethrin, cypermethrin and fenvalerate exhibited good knock down and persistent toxicity against adults of green leafhopper and among the organophosphates and carbamates, chlorfenvinphos was better than the standard monocrotophos and ethion, isoprocarb and chlorfenvinphos showed ovicidal action against green leafhopper. Biswas and Mandal (1992) observed that soaking rice seeds for 12 h in 0.02 per cent solution of phosphamidon, monocrotophos or chlorpyriphos or spraying with 0.05 per cent monocrotophos effectively controlled GLH. Rabbi et al. (1993) opined that phosphamidon (Pilacron 100 SL) and monocrotophos (Megaphos 40 SL) were effective under greenhouse conditions against GLH but were not satisfactory in field tests. Shukla and Kaushik (1994) compared 0.5 kg a.i ha -1 with neem products and found out that the former was effective in controlling GLH. Field studies conducted in Orissa revealed that GLH population could be better managed by integrating neem derivatives at 20 and 70 DAT along with 0.4 kg a.i. ha -1 (Mahapatra and Nanda, 1998). Application of aldicarb 10G at 1.5 kg a.i. ha -1 effectively reduced the GLH population by per cent and consequently increased the yield up to per cent over untreated check (Gupta and Verma, 2001). Efficacy of carbosulfan granules similar to carbofuran granules against rice pest complex was observed through multilocation trials (DRR, 2001). Flufenoxuron at 600 ppm reduced the hatchability of GLH to 35.9 per cent when compared to the untreated check 96.5 per cent, (Chellappan et al. 2002). Murali Baskaran et al. (2009 a) reported that two rounds of spraying of pymetrozine (Chess 400 g ha -1 at 10 days interval on 75 and 85 days after transplanting of rice (Cv. White ponni) during samba season was found effective in reducing the population of rice green leafhopper. Field experiment on rice with ethiprole 40 per cent + imidacloprid 40 per cent g ha - 1 recorded more than 90 per cent reduction in the population of leafhopper and planthopper in rice (Vinodkumar et al., 2010).

26 Brown plant hopper (BPH), Nilaparvata lugens (Stal.) Heong (1975) found that BPH was completely controlled at three days after spraying when the spray pattern was directed towards the plant base and it was only 57 per cent when directed towards canopy. Phosphamidon 0.05 per cent, dichlorvos 0.05 per cent, phorate 1.25kg a.i. ha -1 (Chelliah and Subramaniam, 1974) and carbofuran 1.25 kg a.i. ha (Narayanasamy, 1974; Saivaraj, 1977) effected more than 60 per cent reduction of N. lugens. Kalode (1976) recommended monocrotophos and phosphamidon at 0.4 kg a.i ha -1 for brown planthopper control. Lim and Ong (1978) recommended foliar spraying of monocrotophos against nymphs of brown plant hopper. According to Velusamy et al. (1978), foliar spray of monocrotophos was found to be effective against BPH when applied at 70 and 77 days after transplanting (DAT). Krishnaiah et al. (1982) observed that foliar sprays of carbaryl and monocrotophos were the insecticides for greater knockdown effect and longer persistence against BPH. The effectiveness of monocrotophos against BPH was also reported by Acquino and Heinrichs (1980). Jena et al. (1985) reported the efficacy of FMC 35001, BPMC, MIPC and carbaryl at 0.04 per cent as ovicides against eggs of BPH with 0.0, 2.1, 9.6 and 2.1 per cent egg hatch respectively. Chelliah and Uthamasamy (1986) registered only fewer populations of BPH nymphs on perthane and fenobucarb treated plants. Jena et al. (1986) reported that seed treatment of chlorpyriphos (Dursban ) prevented attack by BPH for up to 26 days. Fenvalerate at 0.3 kg a.i ha -1 was found to be the most effective treatment for the control of BPH (Mann, 1986). Krishnaiah and Kalode (1987) observed that monocrotophos and phosphamidon at recommended dosages were effective against BPH. Phosphamidon brought down the population of BPH during an outbreak in Thanjavur District in 1987 (Natarajan et al., 1988). Monocrotophos at 0.5 kg a.i ha -1 affected egg hatchability of BPH (Senguttuvan and Gopalan, 1990). Gubbiah et al. (1990) reported that monocrotophos was found to be inferior to synthetic pyrethroids in controlling BPH. Rajendran (1993) reported the efficacy of carbofuran 1 kg a.i. ha -1, 1.5 kg a.i. ha -1 and 1 kg a.i. ha -1 against the stem borer and brown planthopper with increased yields over control.

27 In field investigations, ethofenprox at 100 g a.i. ha 1 effectively checked BPH build-up without detriment to the predatory mirid bug, and was superior to monocrotophos at 500 g a.i. ha 1. In view of its extremely low toxicity to mammals, ethofenprox could be preferred for utilization in integrated pest management programmes against leafhoppers and planthoppers in BPH- endemic areas (Krishnaiah and Kalode, 1993). Yasudomi et al. (1994) investigated the insecticidal properties of benfuracarb against the brown planthopper and observed that granular application of benfuracarb was slightly superior to carbofuran. Spraying of imidacloprid at 75 g a.i ha -1 gave much efficient control of BPH than that provided by methamidophos at 750 g a.i ha -1 or buprofezin at g a.i. ha -1 (Qiang et al., 1995). Dash et al. (1996) reported that 0.5 kg a.i ha -1 was effective against BPH when applied at 47 and 70 DAT. According to Krishnaiah et al. (1996), among the granular formulations tested for the efficacy, cartap and isazophos (0.75 kg a.i ha -1 ) were effective against BPH and were on par with carbofuran granules (1 kg a.i ha -1 ). Spray formulations of ethofenprox and carbaryl were effective against BPH and also safer to mirid bug. Teresa and Nachiappan (1997) reported that profenophos 50 EC at 0.25 per cent and monocrotophos 36 SL at 0.1 per cent, effectively checked BPH and GLH and increased grain yield over untreated check, while pymetrozine 25 WP at 0.03 per cent could satisfactorily control BPH. Chaudhari and Bhole (1999) indicated that 0.07 per cent cypermethrin along with azadirachtin (ZA 199) 1.5 per cent was the most effective treatment recording the lowest population of BPH and GLH followed by cypermethrin 0.07 per cent when sprayed alone. Brown planthopper, white backed planthopper in rice were effectively controlled by granular insecticides viz., cartap hydrochloride 4G, chlorpyriphos 15G, carbosulfan 5G, quinolphos 5G, carbofuran 3G and phorate 10G (Lal, 2000). According to Byeongryeol et al. (2001), the residual effect of granule and liquid formulations of 0.3 kg and kg a.i ha -1, respectively lasted for 40 days when applied against BPH. Manjunatha and Shivanna (2001) reported per cent mortality of BPH to imidacloprid at 0.4 ml l -1.

28 Buprofezin (Applaud 25 SC) at 200 and 250 g a.i. ha -1 was the most effective chemical and was comparable with imidacloprid (Tatamida ) at 25 g a.i ha -1 in reducing the population (Kendappa et al., 2005). Panda et al. (2004) reported that from the point of effective insect control, safety to spiders and increased grain yield, and 0.05 kg a.i. ha -1 was found better than carbofuran and phorate. Chau (2007) reported 22 to 78 per cent of plant hopper mortality by fipronil 5 SC. Kumaran et al. (2007) stated that ethiprole g a.i. ha -1 reduced per cent of BPH population when compared to untreated check. Two rounds of spraying different doses of pymetrozine 50 WG at 10 days interval on 75 and 85 days after transplanting of rice (Cv. White ponni) during samba crop revealed that pymetrozine , 350, 300, 250 and 200 g ha -1 was superior in minimizing the population of brown plant hopper resulting in reduction over control of (0.29 nos. tiller -1 ), (0.36 nos. tiller -1 ), (0.58 nos. tiller -1 ), (0.93 nos. tiller -1 ) and (0.29 nos. tiller -1 ) per cent respectively (Murali Baskaran et al., 2009b). Wang et al. (2008) reported that buprofezin was effective against homopteran insect pests, such as planthopper with very low risks to environment and human beings. Ramsingh et al. (2010) found that monocrotophos was the most effective in reducing the BPH population with 28.26, 24.73, and BPH/ 5 sweeps after 24,48, 72 and 120 hours of application respectively as compared to all other treatments and untreated control. Among the neem products, Azadirachtin 1 % EC (Neemarin ) was effective in reducing the population of BPH. The lowest population of BPH and WBPH was recorded in plots treated with buprofezin 25 SC at 1.00 ml l -1 during both the seasons (7.60 and 7.50 /hill) and it was on par with buprofezin 25 SC at 0.75 ml l -1, thiamethoxam 25 WG at 0.20 g l -1 and imidacloprid 17.8 SL at 0.30 ml l -1 and significantly different from all the other treatments (Hegde and Nidagundi, 2009). Jhansilakshmi et al. (2010) suggested the use of insecticides like buprofezin (150 g a.i. ha -1 ) or ethofenprox (100 g a.i. ha -1 ) for the control of hoppers at the early stage of crop (40-45 DAT).

29 White backed brown plant hopper (WBPH) Sogatella furcifera (Horvath) Sasmal et al. (1984) found that sprays of chlorpyriphos and monocrotophos at 0.5 kg a.i ha -1 caused 90 per cent mortality of WBPH within 24 h of application. Saha (1986) reported that 0.5 kg a.i ha -1 and phosphamidon at 0.5 kg a.i ha -1 were effective against WBPH. Foliar spraying with monocrotophos at 80 DAT recorded effective control of WBPH adults (Kushawa et al., 1986; Panda et al., 1989, 1991). Ramaraju et al. (1987) observed that 0.05 per cent had high ovicidal action and caused a reduction in reproductive rates of WBPH. Haq et al. (1991) observed that monocrotophos registered the highest mortality of WBPH after 72 h. Field experiments conducted by Panda et al. (1991) proved that 500 g a.i. ha -1 recorded the best control up to 90 days after treatment. Shukla and Kaushik (1994) reported that sprays of monocrotophos at 0.5 kg a.i. ha -1 resulted in 91.3 per cent reduction of WBPH. Sontakke et al. (1994) compared neem products with insecticides and proved that monocrotophos and chlorpyriphos at 0.5 kg a.i. ha -1 excelled the neem products in controlling WBPH. Akbar et al. (1996) compared the neem products with monocrotophos and methyl parathion and confirmed that monocrotophos was the most effective chemical against nymphs and adult of WBPH. Misra (2009) reported that the new molecule like UPI 206 at 150 g a.i. ha -1 was the most effective insecticide in controlling WBPH of rice followed by its lower dose (75 g a.i. ha -1 ) and clothianidin (12.5 g a.i. ha -1 ), imidacloprid and thiamethoxam (25 g a.i ha -1 ) were the next effective treatments Bioefficacy of carbosulfan against insect pests of rice Krishnaiah et al. (1988) studied the combined application of N fertilizer and insecticide to control rice pests and found that carbosulfan granule was effective against stem borer, gall midge, whorl maggot and case worm next to carbofuran. Efficacy of carbosulfan granules similar to carbofuran granules against rice pest complex was observed in multiplication trials (DRR, 2001). Among the granules insecticides carbosulfan (1000 g a.i.ha -1 ) was on par with carbofuran (1000 g a.i.ha -1 ) and grain yield was higher in carbofuran (47.2 t ha -1 ) (Krishnaiah et al., 2003).

30 Prabhu et al., (2006) stated that Koranda 28 EC at 1750 and 2000 ml ha -1 significantly reduced insect pests of rice over carbosulfan 25EC by recording higher grain and straw yields Stem borer Carbosulfan 6G at 1000 g a.i. ha -1 applied for the management of the rice stem borer, Scirpophaga incertulas (Walker.) resulted in per cent reduction in dead heart and per cent reduction in white ears with a significant increase in grain yield by 31.4 per cent over control (Karthikeyan and Purshothaman, 2000). In aerobic rice, carbosulfan 6G at the same dose of 1000 g a.i. ha -1 at 50 days after sowing reduced the dead heart symptom with 5.49 per cent incidence which was lower than the control with 15.2 per cent incidence of rice stem borer, S. incertulas (Walker.) (Hugar et al., 2009). Studies made by Aalh Baruah et al. (2008) revealed that carbosulfan 20 EC at 350 g a.i ha -1 recorded the lowest stem borer incidence in rice than the lower doses at 250 and 300 g a.i ha Green leaf hopper Reissig et al., (1986) reported that monocrotophos and carbosulfan treatments reduced the density of GLH. Krishnaiah and Kalode (1986) reported that root dip treatment of carbosulfan showed the best control against GLH. Seed treatment with carbosulfan at 0.5 g a.i.100 g -1 of seeds was found to be the most effective against thrips, Stenchetothrips biformis Bagn. (Sathiyanandam et al., 1987). Studies with neem oil, monocrotophos at 0.3l g a.i. ha -1 and carbosulfan 0.3l g a.i. ha -1 on rice GLH indicated that plots treated with monocrotophos and carbosulfan showed higher yield than control plots. At 32 DAT, monocrotophos treated plots has significantly less GLH than control and at 36 DAT carbosulfan treated plots had significantly less GLH than control plots. (Gary Jahn, 1992). Foliar application of carbosulfan 25 g a.i ha -1 was found to be effective in controlling the GLH in rice (Asaf Ali and Chinniah, 1999). When the economic threshold of two GLH/sweep is reached, IRRI recommends spraying a systemic insecticide which increases the grain yield apparently.

31 Murugesan and Kavitha (2009) reported that imidacloprid and monocrotophos were able to reduce the leafhopper population by and per cent respectively. Other treatments viz., acephate, P. fluorescens, phosalone, ethofenprox, dimethoate, neem oil, carbosulfan 25 EC and carbosulfan 25DS resulted in less than 50 per cent reduction in leafhopper population compared to untreated check Brown planthopper Bhavani, (2006) found that among granular formulations, phorate 1000 g a.i./ha and carbosulfan were inferior to the check insecticide, carbofuran g a.i./ha in suppressing plant hoppers (BPH or WBPH) population in rice. Effects of wood vinegar on the activity of various insecticides in brining the mortality of two species of rice plant hoppers, Nilaparvata lugens and Laodelphax striatellus fallen was studied by Kim et al., (2008). Insecticides dinotefuran, imidacloprid and carbosulfan alone gave mortality of 97.3, 54.0 and 16.7 per cent of BPH. and 73.5, 59.3 and 38.0 per cent for L. striatellus respectively and found that wood vinegar has a synergistic effect on the insecticidal activity of carbosulfan. Brown plant hopper N. lugens and white backed planthopper S. furcifera in rice were effectively controlled by granular insecticides viz., cartap hydrochloride 4G, chlorpyriphos 15G, carbosulfan 5G, quinalphos 5G, carbofuran 3G and phorate 10G (Lal, 2000). Utthamasamy and Jayaraj (1985) stated that carbamates were most effective insecticides against BPH. BPMC, dinotefuran, imidacloprid and carbosulfan gave mortality of 99.3, 97.3, 54.0 and 16.7 percent for Nilaparvata lugens Stal. And 98.6, 73.5, 59.3 and 38.0 per cent for Laodelphax striatellus Fallen respectively. If the carbosulfan was treated with wood vinegar it increased the mortality of plant hoppers (Kim et al., 2008).

32 2.4. Bioefficacy of carbosulfan against pests of other crops Cotton Seed treatment with carbosulfan 25 DS at 50 g kg -1 of delinted cotton seed at the time of sowing was found to control leaf hopper very effectively up to 40 DAS compared to two rounds of foliar spray with synthetic insecticides viz., dimethoate, acephate and monocrotophos (Chinniah and Asaf Ali, 1999) and carbosulfan 25 DS at 15g kg -1 of seeds was found to be effective against thrips at earlier stage (Anon., 2009). Two rounds of carbosulfan 25 EC (0.075%) at 15 days interval significantly reduced the population of aphids (97.5%) and leafhopper (84.5%) in field condition. (Asaf Ali and Chinniah, 1999). Three consecutive applications of carbosulfan 25 EC at 250 g a.i.ha -1 at 15 days interval brought down the aphid, leafhopper and thrips population to 3.00, 1.66 and 0.66 / 30 leaves with the reduction of 98.1, 99.5 and 99.2 per cent, respectively over control on 7 days after treatment (DAT). The toxic effect persisted up to 14 DAT (Rajeshwaran et al., 2005). Wang et al., (200 ) studied the resistance of cotton aphid (A. gossypii Glover) and found that carbosulfan could be a good candidate as an alternative to imidacloprid or acetamiprid for managing the aphids on cotton and other crops. Trials conducted to evaluate Pseudomonas fluorescens Migula and neem oil along with eight synthetic insecticides such as acephate 75 SP, carbosulfan 25 DS at 10g kg -1, carbosulfan 25 EC, dimethoate 30 EC, ethofenprox 10 EC, imidacloprid 17.8 SL, monocrotophos 36 SL, and phosalone 35 EC at 10 ml kg -1 as seed treatments against Amrasca devastans (Dist.) in cotton revealed that imidacloprid 17.8 SL and monocrotophos 36SL reduced the leafhopper population by and per cent respectively. Other treatments viz., carbosulfan 25EC at 10 ml kg -1, carbosulfan 25DS at 10 g kg -1, acephate 75 SP, P. fluorescens, phosalone, ethofenprox, dimethoate, neem oil, and resulted in less than 50 per cent reduction in leafhopper population (Murugesan and Kavitha, 2009). Sheeba Jasmine (2002), observed that carbosulfan 25 EC at 300 g a.i.ha-1 effectively reduced the leafhopper population (83.2%) but stood second to methyl demeton at 250 g a.i. ha -1 with the highest per cent reduction of population (86.9%) on 3 DAT in cotton Cv, MCU-7. In the case of cotton thrips, carbosulfan 300 g a.i.ha -1 was the most effective and caused 96.2 per cent reduction followed by methyl demeton at 250 g a.i. ha -1.

33 Cotton jassid was controlled by imidacloprid ( ml ac -1 ) and acetamiprid (150 g ac -1 ), while carbosulfan (500 ml ac -1 ) was ineffective and thrips was effectively controlled by acetamiprid (150 g ac -1 ), imidacloprid ( ml ac -1 ), and methamedophos (500 ml ac -1 ). (Muhammad Aslam et al., 2004). Carbosulfan, oxydemeton methyl, prothiofos, imidacloprid and thiacloprid evaluated for A. gossypii in Parana, Brazil revealed that imidacloprid and thiacloprid gave the best control of A. gossypii at 3 days after application, with at least 96 per cent control. Eight days after application control with these insecticides was 80 per cent (Albuquerque et al., 1999). Four insecticides viz., fipronil 5 SC (Regent), imidacloprid 200 SL, carbosulfan 25 EC and acephate 75 SP at 0.05 per cent concentration tested against cotton whitefly reduced the whitefly populations 85.1, 83.1, 76.6 and 73.7 per cent respectively (Chaudhary and Jaipal, 2006) Okra Carbosulfan 25 STD and carbosulfan 25 EC at 150, 300, 450 g a.i ha -1 effectively controlled the leaf hopper (A. biguttula biguttula) upto 4 weeks after germination (Sucheta and Khokar, 1996). Methomyl and carbosulfan as seed treatment at and six per cent respectively were effective against leafhoppers, whiteflies, aphids, thrips, mites and root knot nematodes in okra and also recorded higher yield of fruits than all other treatments (Harry Jaya Prakash, 1987). Application of carbosulfan (Marshal 25 ST) at 3% w/w as seed treatment followed by application of neem cake and soil application with carbofuran provided significant control of root knot nematode and fruit borer in okra (Sekhar Ghosh and Matiyar Rahaman Khan, 2010). Imidacloprid at 2 ml, thiamethoxam and carbosulfan at 2 g kg -1 seed were found effective in controlling okra leafhopper (A. devastans), whereas imidacloprid at 2 ml, thiamethoxam at 2 g and carbosulfan at 4 g kg -1 seeds were effective in controlling whitefly (Bemisia tabaci Genn.) incidence. Seed yield was higher in thiamethoxam, imidacloprid and carbosulfan treatments. (Rana et al., 2006).

34 Imidacloprid at 2ml, thiamethoxam and carbosulfan at 2g kg -1 seed were found effective in controlling in leaf hopper (Ambrasca devastans Distant), whereas imidacloprid at 2ml, thiamethoxam at 2g and carbosulfan at 4g kg -1 seeds were effective in controlling whitefly (Rana et al., 2006). Seed treatment with carbosulfan at 3% w/w or imidacloprid at 2g/100g seed followed by neem cake at 200 kg/ha and or carbofuran 3G at 1kg a.i./ ha as soil application could be recommended to manage insect and nematode pest problems of okra.(sekhar Ghosh and Matiyar Rahaman Khan, 2010) Brinjal The highest yield increase of brinjal was obtained with carbosulfan at 0.1 per cent followed by triazophos at 0.05 per cent in nursery plots (Reddy et al., 1997). Sheeba Jasmine (2002) found that the per cent damage caused by brinjal fruit borer on fruits both on number (2.8) and weight basis (1.2) was minimum in carbosulfan at 300 g a.i.ha -1 and it was followed by carbosulfan at 250 g a.i.ha -1 (3.3 and 1.8%) which was on par with endosulfan at 350 g a.i.ha -1 (3.3 and 2.0%). Sinha et al. (2009) assessed the damage caused by brinjal fruit borer after application of econeem (Azadirachtin 10,000 ppm) 1 ml l -1, Delfin (Bacillus thuringiensis Ishi.) 1g l -1, spinosad 45 SC 700 g a.i ha -1, cartap hydrochloride 50 SP 500 g a.i ha -1, carbosulfan 25 EC 250 g a.i ha -1 and endosulfan 35 EC 700 g a.i ha -1 and found that carbosulfan 25 EC 250 g a.i ha -1 gave the lowest borer infestation (4.8%) over the control (15.1%) and other treatments. The yield recorded was high in carbosulfan treated plot (24.56 mt ha -1 ) whereas the yield in control plot was 9.16 t ha -1. Carbosulfan 25 EC at 750 ml ha -1 minimised the borer infestation in brinjal and observed that the chemical gave high yield when compared to control (Sinha and Sharma, 2010). The results obtained from the findings of Rahmann. et al.,2010, indicated that Marshal (carbosulfan) and Suntap (cartap) were the most effective insecticides against brinjal fruit and shoot borer. Baral et al. (2006) evaluated carbosulfan 25 EC against eggplant shoot and fruit borer and recommended 2 ml lit -1.

35 Nine insecticides azadirachtin 0.03 EC, abamectin 1.8 EC, flubendiamide 24 WG, chlorpyriphos 20 EC, cartap 50 SP, carbosulfan 20 EC, thiodicarb 75 WP, cypermethrin 10 EC and lambdacyhalothrin 2.5 EC tested against brinjal shoot and fruit borer in lab and field conditions, revealed that carbosulfan and flubendiamide showed the highest toxicity against fourth instar larvae of Leucinodes orbonalis Guen. after 24 and 48 h of exposure, respectively under lab conditions. In field trials, shoot damage was the lowest (0.55% in winter and 1.33% in summer) in carbosulfan treated plot than control plot (4.41% in winter and 12.48% in winter) (Latif et al., 2010). Root dipping of brinjal seedlings in carbosulfan and phosphamidon at 1000 ppm level gave good protection to the crop against the nematode, Meloidogyne incognita (Kofoid and White) and was found to be the best treatment (Venkata Rao et al., 1987). Endosulfan 0.07 per cent and carbosulfan 0.05 per cent recorded the least fruit borer damage in kharif brinjal and in summer crop carbosulfan 0.05 per cent and deltamethrin per cent recorded the least damage and increased yield (Reddy and Srinivasa, 2005) Agricultural and Horticultural crops Carbosulfan as seed dresser at five, six and seven per cent was highly effective in reducing the number of mines per plant, percentage of infested plants and percentage of stem tunneling due to stem fly in french bean crop, which was on par with the soil application of carbofuran. When carbosulfan used as seed dresser at one, two, three, four, five, six and seven per cent a.i. in french bean, improved the germination percentage, the root and shoot length at all levels (Mote and Shah, 1993). Seed treatment with carbosulfan ml kg -1 in combination with Trichoderma 4 g kg -1 recorded the least stem fly damage of 9.6 per cent during kharif and 9.3 per cent during rabi respectively in greengram than the control which recorded a damage of 40.2 and 41 per cent during kharif and rabi seasons respectively. (Sakthivel et al., 2009). Seed treatment with carbosulfan 25 DS at 30 g kg -1 and imidacloprid 70 WS at 3 g kg -1 treated plots were free from stem fly incidence and were on par with the seed treatment with thiamethoxam 70 WS at 3 g kg -1 seed (0.41 % stem tunneling) (Kumar et al., 2009).

36 Carbosulfan 6G evaluated against stem fly and pod borer on mung bean as seed treatment and soil application recorded the least damage of % with carbosulfan 2% followed by 33.33% damage with carbosulfan 4%. (Zahid et al., 2009). Based on per cent reduction in diamond back moth (DBM), Plutella xylostella (Linn.) larval population and increase in cauliflower yield, Chandrasekaran et al. (1994) reported that carbosulfan 250 g a.i.ha -1 was equally effective as cartap 250 g a.i.ha -1 and Biobit 750 g formulation. Shankar et al. (2000) evaluated the efficacy of carbosulfan (Marshal 25 EC) against DBM. In lab experiment, carbosulfan 25 EC at ppm and in field experiment 0.05 per cent were effective. Foliar spraying of carbosulfan 25 EC at 40 ml 100 l -1 of water controlled the thrips, T. tabaci population for more than 2 weeks in onion. (Zaman, 1989). Kumaresan (1982) recorded that carbosulfan at 0.05 per cent was found to be effective against cardamom thrips, Sciothrips cardamomi (Ramk.). Foliar spraying of carbosulfan at per cent had a great control over green peach aphid in chillies (Dhandapani, 1985). Dhaka et al. (2011) evaluated the efficacy of insecticides lambda cyhalothrin 5 EC at 500 ml ha -1, carbosulfan 25 EC at 1000 ml ha -1, indoxacarb 14.5 SC at 500 ml ha -1, bifenthrin 20 EC at 500 ml ha -1, novaluron 10 EC at 750 ml ha -1, flubendiamide EC at 75 ml ha -1, spinosad 45 SC at 500 ml ha -1 and endosulfan 35 EC at 1250 ml ha -1 in vegetable pea found that all the treatments had the comparable lower number of larvae as well as pod and seed infestation than untreated control. Spraying of carbosulfan 25 EC at 300 g a.i ha -1 next to cartap 50 SP at 500 g a.i.ha -1 recorded the least number of P. xylostella on cauliflower. (Mandal and Mandal, 2009). Vastrad et al. (2004) reported better control of Plutella with carbosulfan, thiodicarb and methomyl 40 SP. Carbosulfan was found to be effective at 300 g a.i. ha -1 against Plutella xylostella (L) on cauliflower (Shankar et al., 2000; Vastrad et al., 2004; Mandal and Mandal, 2009), and 250 g a.i. ha -1 in cauliflower (Chandrasekaran et al., 1994). While treating seeds with Carbosulfan 2 %, there is a 53.33% infestation of stemfly in mungbean plants with % occurrence of stem tunneling. Similarly, during soil application of 0.75 kg a.i./ha, there was a % infestation of stemfly in mungbean plants with % occurrence of stem tunneling (Zahid et al., 2009).

37 Rejesus et al. (1986) evaluated the efficacy of different insecticides schedules and reported that chlorpyriphos (0.075%), carbofuran (1.0%) and carbosulfan (Marshal 5 EC, 0.10%) were effective against Thrips palmi Karny on watermelon. Root dipping of chilli seedling in chlorpyrifos, methamidophos, monocrotophos, phosphomidon, acephate or carbosulfan protected the plant for 28 days after planting (Dhandapani and Jayaraj, 1982). Carbosulfan 25 WP was found to be the best treatment, recording 93 per cent population reduction of aphids in summer garden bean crop (Saad et al., 2005). Application of carbosulfan (Marshal 25% EC) was effective against potato aphids (EI-Habieb, 2005). Carbosulfan at 2 ml lit -1 effectively controlled the eriophyid mite on coconut and the results indicated that mite population was reduced by 70 per cent and 68 per cent, after first and second spray respectively. (Muthiah and Rajarathinam, 2002). Root feeding with carbosulfan was found to be effective in controlling the coconut perianth mite. Soundararajan and Justin (2005) observed that the damage level of coconut perianth mite on young nuts was minimum in carbosulfan (18.4%) and garlic + neem oil (32.1%) treated trees after three rounds of treatments. The number of undamaged harvested nuts was high in the carbosulfan and garlic + neem oil treated trees and harboured 41.4 per cent and 32.4 per cent grade 1 nuts, respectively during third harvest. The results of the study by Ramadoss and Sivaprakasam (1994) on cowpea showed that carbendazim at 2 g kg -1 of seed in combination with carbosulfan (4 ml kg -1 ) did not have any adverse effect on seedling vigour and dry matter production indicating the compatibility. Carbosulfan 25 DS at 80 g kg -1 of seeds recorded the least population of sucking pests up to 20 days and also the highest yield in sunflower (Pramod et al., 2002). There was a reduction in the population of sorghum shoot fly, Atherigona soccata Rond., along with lower infestation of dead heart and also less shoot bug population when the seeds were treated with thiamethoxam 70 WS at 2 g kg -1. This was on par with the treatment of seeds with carbosulfan 25 DS at 40 g kg -1, endosulfan 35 EC seed soaking at 2 ml kg -1 and imidacloprid 70 WS at 5 g kg -1 (Vijay Kumar and Prabhuraj, 2007).

38 Studies conducted by Patel et al. (1998) revealed that carbosulfan 25 EC was safe as seed treatment for groundnut, as far as germination is concerned, but less effective than quinalphos 20 AF and 25 EC in controlling white grub in groundnut. Treatment with carbosulfan granules at 10 g and 15 g per pine seedling reduced the mortality of the seedling to 0.7 and 0 per cent respectively. The mortality of untreated seedling ranged from per cent by Hylastes ater Paykull (Reay and Walsh, 2002). Foliar spraying of carbosulfan 25 EC at 0.03 per cent was found effective in controlling the leaf miner, Bilobata subsecivella Zeller in soybean. (Singh and Singh, 1993) Carbosulfan, per cent applied at 10, 20 and 30 days after germination showed the least stem tunnelling by the stem fly Ophiomyia phaseoli Tryon and reduced damage by whitefly, B. tabaci. The highest C: B ratio was obtained with the application of carbosulfan. (Venkatesan and Kundu, 1994). Carbosulfan 25 STD at 150, 300 and 450 g a.i ha -1 gave a good level of control of A. soccata upto 16 months (Rao and Panwar, 1995).When carbosulfan 25 % was applied at 25 ml kg -1 of seeds in groundnut, white grub, Holotrichia consanguinea Blanchard was effectively controlled next to quinalphos 20 % AF (Patel et al., 1998). Field application of carbosulfan at 0.5 g to 1.5 g a.i. per tree was highly effective in reducing termite population and deaths of planted Eucalyptus camaldulensis Labill seedlings (Mazodze, 1992). The studies conducted by Latha et al. (1993) showed that seed treatment with 20 g kg -1 seeds followed by spray with monocrotophos at 31 and 51 days after sowing was considered the most effective chemical treatment for controlling the majority of the insects pests of soybean. Likhil (2006) found that spraying of carbosulfan 25 EC (0.03%) was the most effective in reducing sugarcane woolly aphid.

39 2.5. Phytotoxicity studies Carbosulfan 25 EC alone and in combination with methyl demeton, carbendazim and magnesium sulphate as foliar spray were effective and significantly reduced the sucking pests population without causing any phytotoxicity to cotton plant (Rajeswaran et al., 2005). Seed treatment with imidacloprid 70 WS did not cause any phytotoxic effect on cotton plant at 5, 7.5, 10 and 15 g kg -1 (Mote et al., 1993). Similarly, foliar application of imidacloprid 17.8 SL at and 0.02 per cent did not produce any phytotoxic symptom on cotton (Gupta et al., 1998; Kumar, 1998). Various concentrations of fipronil viz., fipronil 80WG 30 g a.i. ha -1, fipronil 80 WG at 40 g a.i. ha -1, fipronil 80 WG at 50 g a.i. ha -1 on chilli, did not cause any phytotoxic symptoms (Reddy and Shreehari, 2009). Imidacloprid 17.8 % SL with azoxystrobin, wettable sulphur, carbendazim, spiromesifen, dicofol, neem oil, neem seed kernel extract and emamectin at 25 g a.i. ha -1, treatments did not cause any phytotoxic symptoms such as injury to leaf tip and leaf surface, wilting, vein clearing, necrosis, epinasty and hyponasty on chilli (Suganthy et al., 2010). No phytotoxic symptoms were noticed in paddy at any dose of application of cartap hydrochloride and carbofuran (Tejkumar, 2001). Cytone plus 20, 125 and 30 kg ha -1 biozyme 25 kg ha -1 applied at two times did not exibit phytotoxicity in paddy crop (Sreedhara Rao, 2004) Safety to natural enemies Though the insecticides are an important component of Integrated Pest Management (IPM), biological suppression of insect pests to lesser extent is another additive factor. Hence protection and preservation of natural enemies of the pests are essential. Among the various entomophages, coccinellids, spiders, mirids, rove beetles, earthworms and fishes, are very important in rice ecosystem. The toxicity level of insecticides on predators, parasitoids and honeybees are reviewed in this section. Carbosulfan (Marshal) was found to be least toxic against predators in cotton ecosystem (Kadil et al., 1991; Raman and Uthamasamy, 1983). Isofenphos 5G (2 kg a.i.ha -1 ), carbosulfan 10 G (4 kg a.i. ha -1 ), isofenphos 5G (5 kg a.i. ha -1 ) and phorate 10G (4 kg a.i. ha -1 )

40 were found to be safer to natural enemies in groundnut (Rajagopal and Gowda, 1992). The predator and parsitoid populations have declined with application of monocrotophos and chlorpyriphos (Patel et al., 1997). Carbosulfan 25 WP had least effect on common green lacewing Chrysoperla carnea (Stephens) than other treated chemicals such as profenofos, pirimiphos methyl, methornyl and malathion (Badawy and Arnaouty, 1999) Mirids Carbosulfan at normal dose was moderately toxic to eggs of C. lividipennis (Reuter) (Weil et al., 2008). According to the Metcalf (1974) suppression of natural enemies as the result of insecticide spraying has long been believed to be the main factor for pest resurgence. Chiu and Cheng (1976) found that carbamates were as toxic as or more toxic than organophasphates to insect natural enemies found in rice ecosystem. Dyck and Orlido (1977) reported regular spraying with methyl parathion cause reduction in the population of mirid bugs C. lividipennis besides inducing BPH resurgence. Krishnadoss and Abdulkareem (1983) found phenthoate (0.1%) and monocrotophos (0.05%) to cause mortality in the predatory mirid, Cyrtorhinus and they also reported carbofuran show highest contact toxicity to the spiders. Raman and Uthamasamy (1984) also observed 76 per cent mortality in mirid bug population due to exposure to phosphamidon spray. There are a number of works to suggest that the main cause for the emergence of BPH as a secondary pest in rice ecosystem is due to insecticide suppression of natural enemies, particularly spiders, predaceous water stiders of the genera Microvelia and Mesovelia, and the mirid bug, Cyrtorhinus lividipennis Reuter (Kenmore et al., 1984; Heinrichs and Mochida, 1984; and Ooi, 1986). Chelliah and Rajendran (1984) documented endosulfan (0.07%) as least toxic compound to mirid, C. lividipennis followed by neem oil (5.0%), quinalphos (0.075%), chloropyriphous (0.04%), phasolone (0.07%) and monocrotophos (0.08%) were highly toxic to the mirids. Natarajan et al., (1988) reported that the population of natural enemies like mirids, spiders and coccinellids were lesser in plots treated with phosphamidon and quinalphos.

41 The selectivity of neem seed extract on mirids and spiders was documented by Kareem et al., (1988) that monocrotophos (0.75 g a.i ha -1 ) sprayed plot found significantly high in the populations of mirids and spiders than neem treated plots up to 48 days after treatment. According to Jayaraj (1992), population of predatory spiders and mirid bugs were generally unaffected by neem treatments and comparable with those of untreated plot. Sontakke (1993) studied the effect of neem oil against insect pests and their predators in rice reported that neem oil was safe for the mirid bug and spider population since, it was not significantily different from untreated check. Safety of monocrotophos to spider and mirid bug population was reported by Sontakke (1993). However, Sasmal et al., (1995) in their finding reported monocrotophos at 450 g a.i. ha -1 to cause high toxicity to mirid bugs. Neonocotinoid insecticides like imidacloprid and thiamethoxam have been reported to exert adverse effect on C. lividipennis by Mao and Liang (1995). Arida et al. (1997) found that application of methyl parathion did not affect the population of C. lividipennis but reduced the population of spiders and collembolans. Highest toxicity of phosphomidon at 0.4 per cent against spiders was reported by Shanmugavelu and Palanichamy (1991). Ganesh Kumar and Velusamy (1997) reported phosphomidon as less toxic to spiders. According to observation of, Tanaka et al. (2001) deltamethrin and ethofenprox were most toxic insecticides to the spiders. They also observed that C.lividipennis abundance decreased to a low level in all insecticide treated plots except in buprofezin treated plot. Lakshmi et al. (2001b) studied the persistence toxicity of insecticides to rice green mirid bug and they reported acephate to show low persitent toxicity, followed by fipronil (PT valve of 1126), imidacloprid (PT valve of 1284), and thiamethoxam at 12ppm (PT valve of 1342).

42 Karthikeyan and Purushothaman (2003) reported the safety of new molecules to natural enemies. As per the Krishnaiah et al., (2003) the combination of thiamethoxam and imidacloprid (25 g a.i. ha -1 ) with deltamethrin (25 g a.i. ha -1 ) or betacyfluthrin (25 g a.i. ha -1 ) has reduced mirid bugs (MB), in absolute numbers and maintained favourable BPH/MB ratio. Varma et al., (2003) indicated safety of insecticide combination and found that ethiprole g a.i. ha -1, a combination of imidacloprid 5 per cent and betacyfluthrin 5 per 30 g a.i. ha -1, as relativily safe to the natural enemies. However, in their report Lakshmi et al., (2004) indicated that combination products chloropyriphos (50%) + cypermethrin (50%), betacyfluthrin (12.5g) + chlorpyriphos (250g), acephate (45%) + chloripyriphos (5%), imidacloprid (50g) + betacyfluthrin (50g) were less safe to green mirid bug. According to Javaregouda and Krisna Naik, (2005a). Thiamethoxam 25WG was safer the natural enimies like mirid bugs and spiders. Flubendamide 20WDG (RIL-038) was also safe to the natural enimies (Javaregouda and Krisna Naik, (2005b). According to Qing-yu (2006) ground beetle, paederus fusipes Curtis is most sensitive to chlorpyriphos and deltamerthrin and less sensitive to imidacloprid and buprofezin on mortality and predatory function. Acephate 76 SP at g a.i. ha -1 was found highly toxic to green mirid bug, which recorded significantly lesser number of green mirid bug and was on par with ethiprole at 37.5 g a.i. ha -1, (Chen et al., 2008). The granular formulation of benfuracarb 3G applied at the rate of 1500 to 2000 g a.i. ha -1 was found to cause no adverse effect on natural enemies (Dhar et al., 2009). Kumaran et al., (2009) reported ethiprole 10SC at 25 g a.i. ha -1, was found to be least toxic to green mirid bug and they indicated the presence of relatively more predators in ethiprole treated plot. Preetha et al., (2009) while studying nine insecticides, reported thiamethoxam to show high level of toxicity to T. chilonis with an LC 50 of mg a.i.1-1 followed by imidacloprid (0.0027mg a.i.l -1 ). Hegde and Jayapraksh (2009) observed that buprofezin 1.0, 0.75 and 0.50 m l -1, recorded significantily higher predatory mirid bug population over other treatments.

43 Coccinellids Imidacloprid, diafenthiuron, and carbosulfan tested against B. tabaci on cotton revealed that these insecticides were found to be the least toxic against predators. (Kadil et al., 1991). Five routinely used insecticides viz., methyl parathion, quinalphos, monocrotophos, malathion, and endosulfan in mustard crop to control the mustard aphid tested against Coccinella septumpunctata Linn showed that the insecticides malathion and endosulfan were found to be the least toxic and monocrotophos was the most toxic (Shukla et al., 1994). Ten insecticides evaluated against adults of Menochilus sexmaculatus Fabr. revealed that methyl demeton, endosulfan and lindane were less toxic than other insecticides, viz., deltamethrin, cypermethrin, phosphamidan, malathion, fenvalerate and monocrotophos. (Dhingra et al., 1995). Lab experiment conducted to study the influence of 30 pesticides (insecticides, acaricides and fungicides) on mortality and fecundity of different stages of aphidophagous coccinellid, Adalia bipunctata Linn showed that the pesticides fenpropathrin, alphacypermethrin, esfenvalerate, acarinathrin, phosalone, and propoxur + methoxychlor caused high mortality (Olszak, 1999). Plots with seed treatments recorded relatively higher population of natural enemies, coccinellids and Chrysoperla as compared to foliar sprays of imidacloprid in cotton (Katole and Patel, 2000). Comparative toxicity of various systemic insecticides against predatory coccinellids associated with cotton aphid revealed that endosulfan 0.07 per cent and dimethoate 0.03 per cent were found to be significantly safer to the coccinellids followed by methyl O-demeton per cent, monocrotophos 0.04 per cent and phosalone 0.07 per cent. Polytrin 0.04 per cent and phosphamidon 0.03 per cent were comparatively more toxic to the coccinellids (Rathod and Bapodra, 2002). Seed treatment with imidacloprid 70 WS at the time of sowing and imidacloprid 200 SL as foliar spray at 20 and 40 days after sowing resulted in significantly higher number of predatory coccinellid grubs in imidacloprid treated plots, irrespective of formulation and dosages (Day et al., 2005). Bioefficacy of acetamiprid 20 SP evaluated against early sucking pests and their predators in irrigated cotton, at RRS, Raichur revealed that seed dressing had higher population of predators (Patil et al., 2001).

44 Chlorantraniliprole with excellent environmental profile had low impact on fish, birds, and mammals and demonstrated little or no toxicity to common beneficial arthropod species such as chrysopidae, coccinellidae, nabidae, lygaeidae, and braconidae (Anon., 2007a) Spiders Effect of commonly used insecticides in apple trees evaluated showed that spiders were the least susceptible to carbamates and pyridaphenthion (Mansour et al., 1981). Raman and Uthamasamy (1983) reported that carbosulfan was the least toxic to spiders in cotton ecosystem. Studies conducted by Hegde and Patil (1994) revealed that endosulfan 35 EC, cotton seed oil and carbaryl 42 SL produced more than 50 per cent mortality of Amblyseius longipinosus Evans on cotton. Vanitha, (2000) studied the effect of six insecticides, chlorpyriphos, endosulfan, imidacloprid, methyl demeton, monocrotophos, and quinalphos along with Bacillus thuringiensis and neem oil and found that out of the six chemical insecticides tested on spiders, monocrotophos was observed to be more toxic causing the highest mortality of 62.2 per cent followed by methyl demeton (48.88%). Imidacloprid was the safest of all the insecticides tested, causing only 31.1 per cent mortality followed by quinalphos (35.54%). There was no mortality in case of neem, whereas B.t was statistically on par with imidacloprid causing per cent mortality. In the studies conducted in IRRI, it was indicated that foliar sprays of two rates of decamethrine, diazinon and FMC at 34, 74 and 64 DAT resulted in elimination of spider population from rice field (IRRI, 1980). Ye et al. (1981) found that both MPHC and quinalphos adversily affected preadacious spiders and found green mired bug as a natural predator controlling BPH is affected by insecticidal application. It has been observed from publication of Ganesh Kumar and Valusamy (2000) that the toxicants like acephate, chlopyriphos and monocrotophos were safer to wolf spider, Lycosa, Tetragnatha javana (Thorell) and Paederus fuscipes Curtis and acephate was safe to green mirid bug while phorate and carbofuran were found more toxic to green mirid bug.

45 The toxicity of new chemicals evaluated against cotton spiders namely Peucetia viridana (Stolicza), Neoscona theisi (Wacknear) and Oxyopes javanus Throell showed that thiamethoxam at 25 g a.i ha -1 proved to be safer to the spiders, causing less mortality of 13.5 per cent followed by imidacloprid (18.0%) (Mathirajan, 2001) Honeybees Among the eight granular insecticides, four treatments viz., isofenphos 5 G (2 kg a.i. ha -1 ), carbosulfan 10 G (4 kg a.i. ha -1 ), isofenphos 5 G (5 kg a.i. ha -1 ) and phorate 10 G (4 kg a.i. ha -1 ) were found to be safer to natural enemies in groundnut (Rajagopal and Gowda, 1992). Carbosulfan 25% WP had the least effect on common green lacewing Chrysoperla carnea (Stephens) than other treated chemicals such as profenofos, pirimiphos methyl, methomyl and malathion. (Badawy and Arnaouty, 1999). Weil et al. (2008) studied that carbosulfan at normal dose was moderately toxic to eggs of Cyrtorrhinus lividipennis (Reuter). Izzet et al. (2009) examined the acute toxicity of eight insecticides namely Karate 5 EC, Deltanete 400 EC, Sevin 85 WP, Sevin XLR Plus, Marshal 25 EC, Oncol 200 EC, Mesurol 50 WP and Neem Azal with recommended doses on honey bees. Results revealed that all the chemical insecticides had harmful effect on bee while neem was environmentally friendly Earthworm Kring (1969) noticed drastically decreased Lumbricus terrestris L. population in carbofuran treated tobacco field. Among the commonly used insecticides, carbamates are the most toxic and deadly to earthworms. Even small concentration at recommended rates of application can severely reduce the earthworm population (Finlayson et al., 1975; Martin, 1976 and Lebrun et al., 1981). Chio and Sanbporn (1978) reported that L. terrestris could metabolize atrazine. Neuhauser et al., (1986) studied the toxicity of organic compounds to the earthworm (Eisenia foetida Kinberg), by exposing via filter paper in glass vials in a 48-h contact test and reported an LC50 of 16 gcm -2.

46 Reddy and Reddy (1992) found that application of 3 ml 1-1 reduced cent per cent population population of Drawida willis Mich. and Lampito mauritii eugeniae Kinberg. Chloropyriphos was the least toxic to various earthworms including Eudrilus eugeniae (kinberg) with significantily higher survival rate at diffrrent dosages (Mantur, 1998). The acute toxicity of acetamiprid to earthworm was 9 mg kg -1 (Anonymous, 2003). Awaknavar and Karbhantanai (2004) observed endosulfan to be highly toxic with respect to weight and carbofuran with regard to survival. Studies on the response of phorate, cartap hydrochloride and carbofuran granules on earthworms revealed that these insecticides did not affect increase in biomass and survival of adult earthworms (Patla and Srinasta, 2007) Fish The 96-h LC 50 values for nitrobenzene ranged from 24 mg lit -1 for Oryzias latipes (Temminck and Schlegel) to 142 mg lit -1 for guppy Poecilia reticulata (Peters). Yoshioka et al., (1986) reported that medaka were particularly sensitive, with a 48-h LC 50 of 1.8 mg lit -1. Little information was available on long-term effects of nitrobenzene. Canton et al. (1985) reported an acute 18-day LC 50 for nitrobenzene for O. latipes to be 24 mg lit -1. The NOEC, based on mortality and behaviour was 7.6 mg lit -1. Black et al. (1982) exposed rainbow trout Oncorhynchus mykiss (Walbaum) embryo-larval stages sub chronic tests from fertilization to 4 days post-hatching to nitrobenzene under flow-through conditions; total exposure time was 27 days. A wide range of concentrations was used in the test 0.001, 0.01, 0.12, 0.36, 0.91 and 11.9 mg lit -1. An LC 50 of mg lit -1 for nitrobenzene was reported at the time of hatching and at 4 days post-hatching. However, there is doubt about the validity of this figure, because concentrations below 0.12 mg lit -1 were nominal values Soil flora and fauna D h- Yentumi and Johnson (1986) investigated the effect of repeated applications of carbofuran and carbosulfan on soil microbial biomass. The results showed that, carbofuran did not showed any detectable detrimental effects on soil microbial biomass, but repeated application of carbofuran significantly reduced the microbial

47 biomass. The effect of different pesticides viz. Carbofuran, phorate, carbosulfan and thiomethoxam on soil microbial population of leguminous croups was studied by Vinod Dubey et al., (2012). The results showed that, no significant changes in the total viable count of any kind of bacteria due to application of pesticides has been found showing their ability to degrade these pesticides Insecticide residues Residues of carbosulfan Foliar application of carbosulfan 25 EC at 0.75 kg a.i. ha -1 on potato resulted in residue level of 0.05 mg kg -1. Application of carbosulfan 5G at 1 kg a.i. ha -1 resulted in residue level of less than 0.01mg kg -1 of carrot (Anon., 1984). Rouchaud et al. (1991) found that the spraying of carbosulfan did not show any residues in brussels sprouts and cauliflower crops. Khan et al. (1998) evaluated the insecticides viz., dimethoate 40 EC, aflix 38.5 EC (mixture of dimethoate and endosulfan), nogos 50 EC (dichlorvos) and marshall 25 EC (carbosulfan) through stem injection for controlling red palm weevil, dubas bug and mealy bug and when the residues were evaluated after 15 days of injection, there was no carbosulfan residues. But dimethoate residues were detected in green fruits of date palm. Varca et al. (1998) reported that carbosulfan residues lasted till 7 days after spraying in rice leaves. Carbosulfan residues found in fruits and vegetables were 0.05 mg kg -1 (Andersen and Paulsen, 2001). Ginzburg (2001) found that residues of carbosulfan in leafy cabbages, brussels sprouts, cauliflowers and sugar beet was very low. Carbosulfan residue analysed for different doses viz., 250, 500 and 1000 g a.i.ha -1 were below detectable limit in the brinjal fruit sampled for residues at first and third harvest (Sheeba Jasmine, 2002). Carbosulfan residues of ppm observed on the 5 th day brinjal sample could dissipate to ppm in 15 days duration (Reddy and Srinivasa, 2001). Suman et al. (2007) observed that carbosulfan 25 EC at and 375 g a.i. ha -1 was below detectable limit at 7 days after spraying in brinjal. Carbosulfan spray at 250 g a.i. ha -1, showed the residue level to below MRL at the first harvest (Rajeswaran et al., 2004). Trevisan et al. (2004) reported that carbosulfan residue level decreased rapidly and was not found in samples at 7 days after spraying on citrus.

48 Residues of carbosulfan in cotton seed, lint, oil and soil after three applications of carbosulfan at 15 days interval on cotton at 250, 500 and 1000 g a.i. ha -1 was not detectable in any samples of seed, lint, oil and soil (Rajeswaran et al., 2005). The minimum determinable level for carbosulfan was less than 0.02 mg kg 1 for lint, less than 0.01 mg kg 1 for seed, less than 0.03 mg kg 1 for oil and less than 0.01 mg kg 1 for soil. Carbosulfan 20 EC (Sunsulfan) at 1.5 ml lit -1 showed the residue level up to 7 DAS and the residue detected was above MRL up to 3 DAS in brinjal (Kabir et al., 2008). Yashi et al. (2001) evaluated pesticide residues in 595 imported frozen products (517 vegetables and 78 fruit samples) and found that there were no residues of carbosulfan. Among the 69 pesticides tested carbosulfan residue level in tomato was 0.08 and 0.01 mg kg 1 (maximum and minimum concentration) (Sanchez et al., 2010). Residues in the brinjal fruit under Philippine conditions did not vary much for carbofuran from 1 to 8 kg a.i ha -1 but were below the 100 ppb tolerance limits set in edible commodities. (Litainger and Apostol, 1994). Suman et al. (2007) observed that carbosulfan 25 EC at and 375 g a.i. ha -1 was below detectable limit at 7 days after spraying in brinjal. Residues of demeton-o-methyl, carbosulfan, monocrotophos and phosalone analysed in green and dry chillies showed that half-life period was the highest for monocrotophos, followed by demeton-o-methyl, phosalone and carbosulfan and the corresponding waiting periods were 10,10, 2 and 4 days, respectively (Kandasamy et al., 1989) Varca et al. (1998) also reported that in rice leaves, carbosulfan residue last till 7 DAS. Persistence of carbosulfan studied in sterilized and nonsterilized laterite and alluvial soil under flooded conditions showed that carbosulfan appeared to be more persistent in laterite soil than in alluvial soil. (Sahoo et al., 1990). Dissipation of carbosulfan was relatively faster under flooded condition than under field capacity. (Chandrasekaran and Regupathy, 1993). Carbofuran residues were not detected at any depth i.e. 0-15, 15-30, and (cm) in any of the soil samples in the paddy growing tract of Andhra Pradesh (Parthasaradhi et al., 1998).

49 Tariq et al. (2004) found that carbosulfan have less soil sorption coefficients (Koc) than lambda cyhalothrin, bifenthrin, cypermethrin, endosulfan and methyl parathion and more soil sorption coefficients (Koc) than 4-ntirophenol, carbofuran and monocrotophos. Eswara Reddy and Srinivasa (2001) found that deltamethrin residues of ppm detected on the 5 th day reached below detectable level (BDL) from 10 days onwards and carbosulfan residues of ppm observed on the 5 th day brinjal sample could dissipate to ppm in 15 days duration. Baumann (2001) reported that carbosulfan residue in soil was ppm Carbosulfan residues in soil Sahoo et al. (1990) studied the persistence of carbosulfan in sterilized and nonsterilized soil of laterite and alluvial soil under flooded conditions. Carbosulfan appeared to be more persistent in laterite soil than in alluvial soil. Dissipation of carbosulfan was relatively faster under flooded condition than under field capacity (Chandrasekaran and Regupathy, 1993). Carbofuran residues were not detected at any depth i.e. 0-15, 15-30, and (cm) in any of the soil samples in the paddy growing tract of Andhra Pradesh (Parthasaradhi et al., 1998). Baumann (2001) reported that carbosulfan residue in soil was ppm. Carbosulfan have less soil sorption coefficients (Koc) than Lambda cyhalothrin, bifenthrin, cypermethrin, endosulfan and methyl parathion. More soil sorption coefficients (Koc) than 4-ntirophenol, carbofuran and monocrotophos (Tariq et al., 2004). 2.8 Biodiversity The work of Kenmore et al., (1984) and Heong et al. (1990, 1992) indicated that relatively few of the large arrays of natural enemies, at least 188 species through its range (Khoo et al., 1991), might be especially important in BPH control. When little or no insecticide is used, tropical irrigated rice fields possess a rich arthropod community including many different kinds of natural enemies (FAO, 1979), and in these circumstances, their species richness and abundance may sometimes be greater than those of pests (Heong et al., 1991).

50 The impetus for better understanding of the role of natural enemies stemmed from widespread and devasting outbreaks of N. lugens associated with the early green revolution technology in Tropical Asia (Way and Heong, 1994). Field plot experiments have shown that insecticide sprays destroyed natural enemies and detritivores (Heinrichs, 1994; Settle et al., 1996), disorganised predator-prey relationship and food chain linkages (Cohen et al., 1994). Pest suppression using selective insecticides has been highlighted as potentially important ecosystem services of biodiversity in integrated pest management (Way and Heong, 1994; Mooney et al., 1995; Swift et al., 1996; Schlapfer et al., 1999; Wilby and Thomas, 2002). Moreby and Southway (1999) observed higher number of bugs, spiders and beetles in untreated fields than insecticidal treatments. Tanaka et al., (2001) reported that the farmers apply insecticides at indiscriminate rate and frequencies to overcome pest problems but that leads to intervention in biodiversity thereby cause pest resurgence, destruction of beneficial predators and parasitoids besides environmental hazards. Agricultural intensification, including conventional use of pesticide, has resulted in biodiversity losses worldwide (Stoate et al., 2001; Butler et al., 2007). Liu et al. (2008) reported that imidacloprid affects the number and species diversity in communities of arthropods (natural enemies as spiders) strongly than the target pest in agricultural crops. Nearly 350 species of the spiders are reported to occur in the rice ecosystem in south and Southeast Asia (Barrion and Litsinger, 1995). About two third of them are reported from the temperate Asian countries such as Philippines, Japan (90), Taiwan (75), China (61) and Korea (32). In India, 76 spiders species have been reported from Orissa, Andhra Pradesh (Ghode et al., 1985; Meera Gupta et al., 1986) and 21 species from Jammu and Kasmir region (Thakur et al., 1995). The common species observed belong to the genara Tetragnatha, Necoscona, Oxyopes and Pardosa.

51 In Tamil Nadu, Rajendran (1987) reported five spices from Coimbatore region. Subsequently survey by Nirmala (1990) in Coimbatore, Bhavanisagar and Anamalai recorded 14 new species. Later survey by Anbalagan (1994) in the eastern part of Tamil Nadu, revealed the presence of as high as 21 spices of spiders under 16 genera belong to 10 families, where as Ganesh kumar (1994) reported 17 species of spiders occurring in the rice field and border weeds of Coimbatore, 14 from Aliarnagar and nine from Karaikal. Among the spiders reported from rice fields, Lycosa pseudoannulata Boes. et Ster. was the most predominant spices in China (Shi et al., 1991; Li shaoshi 1996), Japan (Chu and Okuma, 1970), Philippines (Mochida and Dyck, 1976), Korea (Kiritani et al., 1972) and in India (Venkateshalu et al., 1998; Nirmala, 1990). However, Tetragnatha mandibulata Gravely had also been reported as the dominant species in India (Chatterjee and Dutta, 1979) and in Bagladesh (Kamal et al., 1992a) Abundance of spider Biswas et al. (1993) observed 28 species of spiders belonging to nine families; 24 species occurring on the rice plants, 8-11 species on the border weeds and 11 on the ratoon crop. Transplanted rice fields had species richness and species diversity than that on bunds, irrigation channels, fallow lands and nursery in Tamil Nadu. The diversity of spiders was more in cultivated field than border weeds in Coimbatore (Ganesh Kumar, 1994). The species richness was greater (4.76) in the cultivated rice fields of Coimbatore than in Aliyarnagar (3.16) and Karaikal (2.76). The species richness in the border weeds was almost identical in all the three situations (Ganesh Kumar and Velusamy, 1996). Turnbull (1962) hypothesized that spider food preference is based on the morphological and seasonal factors in prey that cross species, genus, family and even order boundaries and incorporate large number of diverse animals which vary as their abundance varies seasonally. Irrespective of the spider spicies and their sexes, the prey preference of spider was in the order of Nilaparvata lugens Stal. > S. furcifera > Nephotettix virescens Dist. in rice (Nirmala, 1990). L. pseudoannulata preferred planthoppers to N.virescens, whereas O. javanus preferred N. virescens to plant hoppers (Ganesh Kumar, 1994).

52 CHAPTER III MATERIALS AND METHODS Experiments were conducted to evaluate the bioefficacy of carbosulfan 6G against pests viz., stem borer, leaffolder, green leafhopper, brown planthopper, white backed planthopper, toxicity to natural enemies, phytotoxicity, biodiversity, soil flora and fauna, determination of harvest time residues in rice ecosystem and its effect on the succeeding crop (Black gram). The details of the experiments conducted and methodology followed are described in this chapter. Properties of carbosulfan Chemical name : 2, 3-dihydro-2,2-dimethyl benzofuran-7yl (dibutylamino thio) methyl-carbamate. Common name : Carbosulfan CASRN : Water solubility : 0.3 mg 1 -l (25 C) Vapour pressure : 3.1 x Pa (20 C) Trade name : Marshal Mode of action : Systemic insecticide with contact and stomach poison, Cholinesterase inhibitor. Empirical formula : C 20 H 32 N 2 O 3 S Structural formula :

53 Plate 1. Field experiment on rice I Season TNAU, Coimbatore Plate 2. Field experiment on rice II Season TNAU, Coimbatore

54 Molecular weight : Formulation : 25 EC/GR/DS Source : FMC India Ltd, Bangalore Field experiments Two supervised field trials were laid out in randomized block design with three replications at Paddy Breeding Station (PBS) Tamil Nadu Agricultural University Coimbatore during November and August respectivily, with the rice cultivar, Co- 51 to evaluate the bioefficacy of carbosulfan 6G (NS) against rice pests, phytotoxicity, biodiversity, toxicity to natural enemies and determination of terminal residues in rice ecosystem. The plot size adopted was 40 m Evaluation of bioefficacy on rice pests Bioefficacy of carbosulfan 6G (New Source- NS) and carbosulfan 6G ES (Existing Source ES) was evaluated against pests of rice. Phorate 10G was taken as the standard check. Experimental details S. No Treatment Dose (g a.i. ha -1 ) Dose ( kg ha -1 ) 1. Carbosulfan 6G (NS) Carbosulfan 6G (NS) Carbosulfan 6G (NS) Carbosulfan 6G (NS) Carbosulfan 6G (ES) Phorate 10G Untreated control -

55 Plate 3. Field experiment on Succeeding crop (Black gram)

56 Granular application were given in the first and second season trials at 21 and 45 DAT days interval commencing from transplanting by broadcasting method. The observations were taken at 7, 14 and 21 days after each application. The observations on the population count of BPH, WBPH and GLH were made on five tagged hills per plot. Whereas, in case of stem borer per cent infestation due to dead heart (in vegetative stage) and white ear (panicle emergence stage) and leaf folder damage were recorded from randomly selected ten (10) hills per plot and expressed as number hill a. Natural enemies In both the field trails, toxicity of carbosulfan 6G was evaluated to natural fauna of rice ecosystem particularly to spiders, mirids and rove beetle in ten randomly selected plants per plot in all replications and the population was expressed as number five plants b. Yield assessment Rice and straw yield per plot was recorded and pooled to arrive at the total yield per hectare Evaluation of phytotoxicity Phytotoxicity of carbosulfan 6G was evaluated on rice ecosystem in paddy breeding station (PBS) Coimbatore during the seasons mentioned in section 3.1. The experiments were laid out in RBD with three replications on rice cultivar viz CO-51 in plots size of 40 m 2 for both the trials. The treatment details are given below. S. No Treatment Dose (g a.i. ha -1 ) Dose ( kg ha -1 ) 1. Carbosulfan 6G (NS) Carbosulfan 6G (NS) Carbosulfan 6 G (ES) Carbosulfan 6 G(ES) Untreated control - -

57 A. Occupational Exposure to Applicator B. Field investigation by Dr. S. Kuttalam C. Chemical preparation and application Plate 4. Carbosulfan 6G (NS) application activities on rice pest management

58 Method of assessment To know the crop tolerance, the plants were observed on 1, 3, 5, 7 and 10 days after application as per the protocol of Central Insecticide Board, Registration Committee (C.I.B. R.C) for the phytotoxic symptoms like; a. Injury to leaf tip and leaf surface, b. Wilting, c. Vein clearing, d. Necrosis, e. Epinasty and f. Hyponasty which were recorded based on the following visual rating scale of Rating Phytotoxicity (%) 0 No phytotoxicity The per cent leaf injury was calculated using the formula, Total grade points Per cent leaf injury = X 100 Max. grade X No. of leaves observed

59 3.2. Laboratory studies Earth worms The earth worm, Eudrilus eugeniae (Kinberg) and Perionyx excavatus obtained from Central farm, Tamil Nadu Agricultural University, Coimbatore was used to test the toxicity in soil as media. The effect of carbosulfan 6G on earthworm E. eugeniae and P. excavatus was tested by following the artificial soil test method proposed by Biollogische Bundesanstalt fur Land-und Forst Wirsts chaft, Braunschweig (BBA) as reported by Ganesh Kumar (2000). The test substrate was prepared by mixing fine quartz sand (83.5 per cent particle size between 0.06 and 0.2mm), bentonite 5 per cent, finely ground and dried sphagnum peat 10 per cent, pulverized calcium carbonate (1%) and ground dried cow dung (0.5%). The ph was adjusted to 7 ± 0.5 and sufficient water was added to bring moisture content to 40 per cent of dry weight of the substrate. The complete mixture was moist enough, but not so wet that water appeared when the artificial soil was compressed. One kg of conditioned soil in tubular pots (18 x 6 cm) was treated with different doses of carbosulfan 6G and 15 earthworms washed cleanly in water were placed on the top of the substrate. The tubular pots were covered with perforated polythene cover to prevent the worms from crawling out and to avoid evaporation. The set up was kept under shade. After 7 days, 5 g of finely ground dried cow dung was mixed inside the container and water lost by evaporation was replaced. The number of live earthworms was counted. Earthworms were considered dead if they did not respond to a gentle mechanical stimulus (Edwards and Bohlen, 1992). The LC 50 was calculated by probit analysis (Finney, 1971). Untreated control was maintained throughout the experiment Fish The inland water fish, common carp (Cyprinus carpio Linnaeus) mrigal, Cirrhinus mrigala obtained from Aliyarnagar, Fisheries Department, Government of Tamil Nadu, was used for conducting safety test. The acute toxicity of carbosulfan 6G was assessed as per the methodology described by Sprague (1969 and 1970). The aquarium tanks of dimensions 15 cm x 30 cm x 45 cm

60 with 80 l capacity were provided with artificial aeration facilities. Carbosulfan 6G at different concentrations viz., 300, 600, 900, 1200, 1500 and 1800 mg per 20 litre of water were taken as different treatments after range finding test and control tanks were maintained without carbosulfan 6G. Each experiment was replicated three times. To each tank, 20 fish of similar size starved for 12 hours were released. Observations on mortality were made on 3, 6, 12, 18, 24 and 48 h and median lethal concentration (LC 50 ) was worked out. 3.3 Residue analysis Sampling Samples were collected at harvest time after last application from each replicate of three treatments applied with carbosulfan 6G (NS) at the rate of 1000 and 2000 g a.i./ha. Control samples were collected similarly from the untreated plots. The samples collected from three replications for each treatment were used for residue analysis. Soil samples were collected at 10 days after application; using augur driven to a depth of 15 cm. A minimum of 10 cores were taken across the field and bulked together, from which a single representative sample of 100 g was taken by quartering technique. From this, a sub sample of 25 g of soil was taken for residue studies Reagents Acetonitrile with HPLC grade, methanol with HPLC grade, anhydrous magnesium sulphate, sodium chloride, trisodium citrate dihydrate, disodium citrate sesquihydrate, (reagent grade), primary secondary amines (PSA) and 5 per cent formic acid Extraction A representative sample of 10 g samples (rice, straw, bran, husk, and soil,) and black gram samples (grains, and husk) were taken and blended with 50 ml acetonitrile for 2 min at high speed. By using 50 ml centrifuge tube shaken vigorously for 1 min after addition of 4g Magnisum sulphate unhydrous, 1g sodium chloride, 1g trisodium citrate dehydrate, and 0.5g di sodium citrate sesquihydrate. Each tube directly after the salt addition was shaken vigorously for 1 min, with phase separation, and centrifuged for

61 Plate 5. Acute toxicity of Carbosulfan 6G to fishes A.Perionyx excavat r B. Experimental setup Plate 6. Acute toxicity of Carbosulfan 6G to earthworms

62 5 min at 3000RPM. Then X ml of the extracts was transferred into a PP single use centrifugation tube, which contained X*25mg primary secondary amines (PSA) and X*150mg anhydrous megnisum sulphate (MgSO4), then shaken well for 30 sec and again centrifuged for 5 min at 3000 RPM. Then Y ml of the extracts was transferred into screw cup vial, and acidified with Y*10 micro liter 5 per cent formic acid in acetonitrile (10microliter/ml exract) and the cleaned and acidified extracts were transferred into auto sampler vials and used for the residue determination by HPLC techniques Clean up The c-18 cartridge clean up method, described by Sharp and Bramlett (1983) was used for analysing carbamate residues. The c 18 cartridge was prewet with 2.8 ml methanol and the eluant was discarded. Condensed extract dissolved in 5ml methanol was transferred quantitatively onto prewet C-18 cartridge. The eluate was collected from cartridge in 5 ml volumetric flask. Cartridge was eluted with additional methanol to make up volume to 5.0 ml. Final concentration of cleaned up extract is 1.45 mg µl -1 (7.25 g ml -1 ) End analysis Standards The reference standard carbosulfan received from FMC India Ltd. was used for the preparation of stock solution, spiking and quantification of residue in the sample matrices a. Concentrated stock solution From the technical standard of per cent purity, 107 mg was weighed and transferred to a 100 ml volumetric flask with methanol (HPLC grade) and the volume was made up. Then the flask was shaken well to get a homogenous solution of 1000 ppm and was stored in refrigerator at 4 0 C b. Intermediate stock solutions The concentrated stock solution was brought to room temperature and one ml from the concentrated stock solution was transferred to a 100 ml volumetric flask.

63 The volume was made up and the flask was shaken well to obtain homogenous solution of 10 -ppm standard solution. This was utilized for spiking the samples for recovery studies c. working standard From the intermediate stock solution, working standards of 0.05, 0.1 to 0.5 ppm were prepared by diluting one ml of 10 ppm solution to times. These working standards were derivatised with derivatising agent methonal (HPLC grade) to find out the retention time and for quantitative determination of residues in samples Fortification The samples were fortified to 0.05, 0.1 to 0.5 ppm by adding required quantity of 1 to 10 ppm standard stock solution Final determination Carbosulfan residues were estimated by Cyper lab LC100 model HPLC equipped with UV detector fitted with c-18 column. The following were the operating parameters. Column : c-18 column Temperature : Ambient temp. (40 0 C) Detector : UV Wavelength : 269 nm Mobile phase : Time (min) Water (%) Methanol (%) Flow rate : 1.0 ml/min. Total run time : 10 min The final quantification was worked out using the formula A s W std V s Residues = X X A std W s A sj

64 Where, A s - Peak area of the sample A std - Peak area of the standard W std - Weight of the standard in ng Ws - Weight of the sample in g Vs - Volume of the sample (final extract in ml) Asj - Aliquot of the sample injected in l 3.3 Bio diversity The present investigation was carried out to study the arthropod diversity in rice ecosystem in paddy breeding station (PBS), TNAU during The various methodologies followed for collection of arthropods, preservation and their identification and diversity analysis are detailed below Experimental sites The experiment was conducted at the paddy breeding station (PBS) in rice ecosystem At each of these sites, sampling was carried out in 10 m x 10 m quadrats. Observations were taken from November and August with the rice cultivar, CO Sampling methods To develop a package of methods for quantitative sampling of arthropod communities, collections were made using four different methods viz., active searching, net sweeping, vacuum insect collector, pitfall trap and rubbish trap. For carrying out arthropod collection, the plot was divided into 100 quadrats (10 m x 10 m). Five such quadrats were chosen each at random and the entire plot was covered during the sampling period.

65 3.3.3 Collecting devices Active searching Active searching was done in the early morning or evening hours. Each quadrat was selected at random and they were actively searched for arthropods. Each site was searched for a total of two hours. Spiders were collected by walking diagonally in the fields and care was taken to capture them without injuring and transferred to polythene bags for further studies. Specimens from a single quadrat at each habitat type were pooled for analysis Net sweeping Sweeping is very effective for the collection of flying and jumping arthropods at the ground level and under storey vegetation. The nets used in systematic sweeping of the ground level were made of thick cotton cloth with a diameter of 30 cm at the mouth and a bag length of 60 cm. For carrying out net sweeps, the plot was divided into 100 quadrats, measuring 10 m x 10 m each. Five such quadrats representing the field were chosen at random and the entire ground level vegetation in the chosen quadrat was covered during the sweeping. Net sweeps were always done between 10 am and 12 noon. The arthropods collected from each quadrat were transferred into polythene bags containing cotton dipped in chloroform. The sweeps were made at ground vegetation above the height of the crop from the ground for collecting insects from crop. The contents from the sweep nets were placed in a bucket with a small amount of ethyl alcohol to kill all the arthropods and were sorted on the same day. Spiders and other arthropods were separated from the vegetation. Soft bodied insects and spiders were later separated from the bag and preserved in vials containing 70 per cent alcohol Rubbish traps These traps were constructed using chicken wire mesh, stuffed with leaf litter (45 cm length and 15 cm width). Five rubbish traps were placed in each of five randomly around the bonds plots. The traps were placed in the field allowing a week for arthropods

66 Aspirator Vacuum insect collector Net sweeping Pitfall Trap Plate 7. Sampling techniques

67 to take up residence. Every seven days, these traps were removed and brought to the laboratory and arthropods found inside were collected Vacuum insect collector (D-Vac Vacuum Insect Net Model 122) The power operated hand-carried Model 122 was used for taking quick samples for field checking because of its compact design. It has an Echo air-cooled 2-cycle, 1 horsepower motor and Revcor fan. The standard D-VAC collection unit has a square foot opening and protective collar and comes with a collecting cone, 4 nylon organdy collecting bags and a medium mesh screen sieve bag for separating samples by size. It runs on gasoline mixed with oil. It weights approximately 23 lb. (10.5 kg). The airstream could reach approximately 280 cu. ft. /min. The advantage of the D-Vac vacuum sampling is the more complete extraction of tiny species and immature forms of even the larger insects. Insects of low body mass simply do not enter conventional sweep nets that build up an overflow of air pressure as the net is sent through the air. This net approach the plant as quickly as possible using a swinging motion to surprise and thereby catch a larger proportion of the quick flying species and the ones that tend to drop or to hold on vigorously if they are warned of the approach of the collector net. This method is very useful for assessing the balance of predators and parasites as well as pests. Collection was taken up weekly interval and collected in separate polythin covers finally separated and identified in the laboratory and stored Collection and identification of arthropods The collection of arthropods for biodiversity analysis was carried out in rice field at different stages of the crop growth. Arthropod fauna were collected on weekly basis from third week of November and August using the methods specified earlier. The collected arthropods were sorted out based on taxon. Soft bodied insects and spider species were preserved in 70 per cent ethyl alcohol in glass vials. Other arthropods were card mounted or pinned. The preserved specimens were photographed and identified based on the taxonomic characters. All arthropod species were identified to the lowest possible taxon. Insects were identified following Richards and Davis (1983), Lefroy (1984), Comstock (1984), Ayyar (1984), Poorani (2002) and also by comparing with the specimens in the

68 Department of Agricultural Entomology, Tamil Nadu Agricultural University. Spiders were identified with the help of Dr. M. Ganesh Kumar, Professor of Agricultural Entomology. Coimbatore Diversity analysis of arthropods in floricultural ecosystems Alpha diversity indices Measures of diversity are frequently seen as indicators of the well being of any ecosystem. They also serve as a measure of the species diversity in the ecosystem. The following indices were used to assess and compare the diversity and distribution of arthropods in rice. Species richness and diversity II (Pisces Conservation Ltd., (Henderson, 2003) programmes were used to assess and compare the diversity of arthropods in rice ecosystems Species richness a Fishers alpha (Fisher et al., 1943) This presents the alpha log series parameter for each sample. This is a parametric index of diversity that assumes the abundance of species and follows the log series distribution. αx, αx 2 / 2, αx 3 / 3. αx n / n Where, each term gives the number of species predicted to have 1, 2, 3,., n individuals in the sample b. Q Statistic (Kempton and Taylor, 1976) This presents the interquartile diversity index for each sample. It measures the interquartile slope of the cumulative abundance curve and is estimated by, Q = 1/ 2 n R 1 + nr + 1/ 2 n R 2 / ln (R 2 / R 1 ) Where, nr = the total number of species with abundance R R 1 and R 2 = 25% and 75% quartile of the cumulative species curve nr 1 = the number of individuals in the class where R1 falls nr 2 = the number of individuals in the class where R2 falls

69 c. Species number ( Magurran, 1987) This represents the total number of species in each sample d. Margalef s D (Clifford and Stephenson, 1975) Margalef s D has been a favourite index for many years. It is calculated as species number minus one divided by the logarithm of the total number of individuals. This program uses the natural logarithm. D Mg = (S 1) / ln N Where, S = total number of species recorded N = the total number of individuals summed overall S species e. Shannon diversity index (Batten, 1976) This represents the Shannon - Weiner (also called as Weaver) diversity index for each sample and is defined as: H = P i ln P i Where P i = the proportion of individuals in the i th species This program calculates the index using the natural logarithm f. Brillouin diversity index (Magurran, 1987) The Brillouin index H is calculated as follows: H = ln N! - s i = 1 ln n i! / N Where, N is the total number of individuals in the sample. n i is the number of individuals belonging to the i th species and s is the species number.

70 Species Dominance indices a. Simpson s index (Simpson, 1949) Simpson s index describes the probability that a second individual drawn from a population should be of the same species as the first. D = Σ [N i (N i 1)] / [N t (N t 1)] Where, N i is the number of individuals in the i th species N t is the total number of individuals in the sample So, larger its value, greater the diversity. The statistic 1 - C gives a measure of the probability of the next encounter being from another species (Hulbert, 1971) b. Berger Parker diversity index (Berger and Parker, 1970 and May, 1975) A simple dominance measure is the Berger parker index. The index expresses the proportional importance of the most abundant species. Where, d = N max / N N max is the number of individuals in the most abundant species N is the number of individuals in the sample This simple index was considered by May (1975) to be one of the best. It is simple measure of the numerical importance of the most abundant species c. McIntosh index (McIntosh, 1967) This index was calculated using the following formula proposed by McIntosh (1967) as Where, D = N U / N (N) N is the total number of individuals in the sample U is given by the expression, U = (Σ n i 2 )

71 Where, n i is the number of individuals belonging to the i th species and the summation is undertaken over all the species Evenness indices Evenness (E) is a measure of how similar the abundances of different species or categories are in a community. When all species in a community are equally abundant, the evenness index should be maximum and decrease towards zero as the relative abundances of the species diverge away from evenness closer to zero. It indicates that most of the individuals belong to one or a few species or categories, when the evenness is close to one; it indicates that each species/ category consists of the same number of individuals a. Equitability J (Magurran, 1987) Equitability or evenness refers to the pattern of distribution of the individuals between the species. This measure of equitability compares the observed Shannon- Weiner index against the distribution of individuals between the observed species which would maximize diversity. If H is the observed Shannon - Weiner index, the maximum value this could take log (S), where S is the total number of the species in the habitat. Therefore the index is: J = H / log (S) Beta diversity indices Beta diversity measures the increase in species diversity along transects and is particularly applicable to the study of environmental gradients. It measures two attributes, the number of distinct habitats within a region and the replacement of species by another between disjoint parts of the same habitat. All the selected samples in the active data set will be used to calculate the indices. It is assumed that the samples are arranged in the data grid in their order of occurrence along the transect. The six indices calculated, which are described below are those considered by Wilson and Schmida (1984). All six required presence/ absence of data.

72 Whittaker s measure βw The first and one of the most straight forward measures of beta diversity was introduced by Whittaker (1960). βw = S / α 1 Where, S = the total number of species and the average species richness of the samples α = the average sample diversity where each sample is standard size and diversity is measured as species richness All samples must have the same size (or sampling effort) Cody Bc Cody Bc was introduced to analyse the changes in the composition of communities along habitat gradients. βc = g(h) +l(h)/ 2 Where, g(h) is the number of species gained and 1(H), the number lost moving along the transect Routledge s R, I and E Routledge (1977) was concerned with how diversity measures can be portioned into alpha and beta components. The following three indices were derived from his work. The first measure β R, takes overall species richness and the degree of species overlap into consideration. Where, β R = S 2 / 2r+S-1 S is the total species number for the transect and r is the number of species pairs overlapping distributions. Second equation simplified for qualitative data and equal sample size Assuming equal sample sizes, β I = log(t)-[(1/ T) Σ e i log (e i )] [(1/ T) Σα i log(α i )]

73 Where, e i = is the number of samples along the transect in which species i is present and α i the species richness of sample i and T is Σ e i. α = the average sample diversity where each sample is standard size The third index β E is simply the exponential form of β I The third Routledge s index is simply β E = exp(β I ) Wilson and Schmida s T Wilson and Schmida (1984) proposed the sixth measure of beta diversity. This index has the same elements of species loss (1) and gain (g) that are present in Cody s measure and the standardization by average sample richness α, which is a component of Whittaker s measure β T = [ g(h)+1(h)] / 2α where the parameters are defined as c and w based on an assessment of the essential properties of a useful index: ability to detect change, additivity and independence of sample size. Wilson and Schmida (1984) concluded this as the best Similarity index The binary data obtained by scoring the presence and absence of individual species in each of sampling site ecosystems were subjected to cluster analysis. Similarity matrix was constructed using Bray-Curtis per cent similarity. The similarity values were used for cluster analysis. Sequential Agglomerative Hierarchical Non-overlapping (SAHN) clustering was done using Unweighted Pair Group Method with Arithmetic averages (UPGMA) method. Data analysis was done using NTSYSpc version 2.02 (Rolff, 1998). 3.5 Statistical analysis The corrected per cent reduction of pests over control in the field population was worked out by using the formula given by Henderson and Tilton (1955).

74 Ta C b Corrected per cent reduction = 1 x 100 Tb Ca Where, T a - Number of insects in the treatment after spraying T b - Number of insects in the treatment before spraying C b - Number of insects in the untreated check before spraying C a - Number of insects in the untreated check after spraying The data on population number were transformed into x 0.5 and per cent data into angular values before statistical analysis. The data obtained from field experiments were analysed in completely randomized design (Gomez and Gomez, 1984) and the mean values were separated using Duncan s Multiple Range Test (DMRT) (Duncan, 1951).

75 CHAPTER IV EXPERIMENTAL RESULTS The results of the various experiments conducted to evaluate the bioefficacy, phytotoxicity, impact of natural enemies, biodiversity, and harvest time residues of carbosulfan 6G (NS) on rice insect pests and followed by succeeding crop (black gram) for the carryover residues and laboratory safety studies of carbosulfan 6G to fish and earth worms are presented in this chapter Field experiments The results of two field experiments conducted first during November and second during August at Paddy Breeding station (PBS), Tamil Nadu Agricultural University, are presented below Bioefficacy of carbosulfan 6G against insect pests of rice Rice stem borer The per cent dead heart and white ear head caused by rice stem borer were recorded before the first application as well as 7, 14 and 21 days after application (DAA). In the pre treatment count, the per cent dead heart among experimental plots were found to be uniform ranging between and and was not significant by different from one another (Table 1). The per cent dead heart observed after first spray on 7 DAA was 8.91 in carbosulfan 6G (NS) 1250g a.i.ha -1 treated plots followed by 9.01, 9.65, 9.98, 10.00, and in carbosulfan 6G (NS) 1000, 750, 600 g a.i. ha -1, carbosulfan 6G (ES) 1000 g a.i. ha -1 and phorate 10G 1000 g a.i.ha -1 treated plots, respectively. At 14 DAA also, carbosulfan 6G (NS) at 1250 g a.i. ha -1 recorded the least damage (6.83%) which was on par with lower dose of 1000 g a.i. ha -1 (7.00%) and 750 g a.i. ha -1 (7.90%). At 21 DAA, carbosulfan 6G (NS) 1250 g a.i. ha -1 (6.62%), 1000 g a.i. ha -1 (6.69%), carbosulfan 6G (NS) 750 g a.i. ha -1 (6.72%) were on par (Table 1).

76 Table 1: Effect of carbosulfan 6G on damage caused by stem borer in rice (Location: PBS, TNAU, Coimbatore I season) PTC 7DAT 14DAT 21DAT Mean PR PTC 7DAT 14DAT 21DAT Mean PR Percent damage Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha (18.13) ab (16.64 )c (15.70) ab (16.84) (12.91) b (12.37) b (12.08) b (12.46) Carbosulfan 6G 750 g a.i. ha (18.10 )ab (16.32) abc (15.02 ) a (16.54) (12.55) b (12.41) b (12.36) b (12.44) Carbosulfan 6G 1000 g a.i. ha (17.47) a (16.34) ab (14.99) a (15.97) (10.95) a (10.32) a (10.32) a (10.54) Carbosulfan 6G 1250 g a.i. ha (17.37) a (15.15) a (14.91) a (15.84) (10.66) a (10.12) a (10.17) a (10.32) Carbosulfan 6G 1000 g a.i. ha (18.43) ab (16.43) abc (16.32) b (17.09) (12.68) b (12.55) b (12.29) b (12.51) Phorate 1000 g a.i. ha (18.86) b (16.64) c (16.31) b (17.30) (12.89) b (12.51) b (12.36) b (12.59) Untreated control (20.63) c (20.45) d (20.56) c (20.55) (20.70) c (20.60) c (20.64) c (20.65) DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in Parentheses are arc sine transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

77 After second application, the per cent white ear recorded on 7 DAA was the lowest in carbosulfan 6G (NS) 1250 g a.i. ha -1 (3.42%), and it was on par with its lower dose of 1000 g a.i. ha -1 (3.61%), and it was fallowed by carbosulfan 6G (NS) 750 g a.i. ha -1 (4.72%) and carbosulfan 6G (ES) 1000 g a.i. ha -1 (4.82%). Similar trend was observed on 14 and 21 DAA also (Table 1). In second season, the pre treatment per cent dead heart was found to be ranging between and among experimental plots and was found to be non significant (Table 2). The per cent dead heart observed after first spray, at 7 DAA was 9.98 in carbosulfan 6G (NS) 1250 g a.i. ha -1 treated plots followed by 10.12, , 11.53, 11.82, and in carbosulfan 6G (NS) 1000, 600 g a.i. ha -1, carbosulfan 6G (ES)1000 g a.i. ha -1, carbosulfan 6G (NS) 750 g a.i. ha -1 and phorate 10G 1000 g a.i. ha -1 respectively. At 14 DAA, carbosulfan 6G (NS) at1250 g a.i. ha -1 recorded the least damage (9.53%) and was on par with carbosulfan 6G (NS) 1000 g a.i. ha -1 (9.62%) and carbosulfan 6G (ES) 1000 g a.i. ha -1 (10.80 %). At 21 DAA, carbosulfan 6G (NS) 1250 g a.i. ha -1 (8.50%), 1000 g a.i. ha -1 (8.80%) and carbosulfan 6G (ES) 1000 g a.i. ha -1 (9.20%) were found to be on par (Table 2). After second application, the per cent white ear recorded on 7 DAA was the lowest (3.80%) in carbosulfan 6G (NS) 1250 g a.i. ha -1, and was followed by carbosulfan 6G (NS) 1000 g a.i. ha -1 (4.01%), carbosulfan 6G (NS) 750 g a.i. ha -1 (4.21%) and carbosulfan 6G (ES) 1000 g a.i. ha -1 (4.50%). Similar pattern was observed on 14 and 21 DAA. Based on the per cent reduction in per cent of dead hearts and white ear over untreated check after two application in both seasons, the order of efficacy of different treatments is as follows: carbosulfan 6G (NS) 1250 g a.i. ha -1 > 1000 g a.i. ha -1 > 750 g a.i. ha -1 > carbosulfan 6G (ES) 1000 g a.i. ha -1 > carbosulfan 6G (NS) 600 g a.i. ha -1 > phorate 10G 1000 g a.i. ha -1 (Tables 1 and 2) Rice leaf folder The per cent leaf damage caused by rice leaf folder in the first season was observed before first application as well as 7, 14 and 21 DAA. In the pre treatment count, the per cent leaf damage was found to be uniform ranging between and among experimental plots and was not significant (Table 3). The per cent leaf damage

78 Table 2: Effect of carbosulfan 6G on damage caused by stem borer in rice (Location: PBS, TNAU, Coimbatore II season) PTC 7DAT 14DAT 21DAT Mean PR PTC 7DAT 14DAT 21DAT Mean PR Percent damage Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha (19.69) abc (19.55) b (17.75) a (19.01) (12.04) ab (11.95) bc (12.00) bc (12.00) Carbosulfan 6G 750 g a.i. ha (20.11) cd (19.48) b (17.56) a (19.07) (11.84) ab (11.54) abc (11.71) bc (11.70) Carbosulfan 6G 1000 g a.i. ha (18.55) ab (18.07) a (17.26) a (17.97) (11.55) ab (10.97) ab (11.09) ab (11.21) Carbosulfan 6G 1250 g a.i. ha (18.42) a (17.98) a (16.95) a (13.34) (11.24) a (10.64) a (10.47) a (10.79) Carbosulfan 6G 1000 g a.i. ha (19.85) b (19.19) ab (17.66) a (18.92) (12.25) ab (11.83) abc (12.00) bc (12.02) Phorate 1000 g a.i. ha (20.17) cd (19.30) ab (17.77) a (19.10) (12.53) b (12.53) c (12.67) c (12.58) Untreated control (21.31) d (21.24) c (21.21) b (21.25) (21.31) c (21.51) d (21.54) d (21.46) DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per centreduction, PTC: Pre treatment control Figures in Parentheses are arc sine transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

79 Table 3: Effec t of carbosulfan 6G on damage caused by leaf folder in rice (Location: PBS, TNAU, Coimbatore I season) PTC 7DAT 14DAT 21DAT Mean PR PTC 7DAT 14DAT 21DAT Mean PR Percent damage Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha (18.82) b (17.07) b (14.74) ab (16.95) (13.42) b (10.83) c (10.64) bc (11.70) Carbosulfan 6G 750 g a.i. ha (18.63) b (16.87) b (14.50) a (16.74) (13.17) ab (10.78) a (10.17) bc (11.44) Carbosulfan 6G 1000 g a.i. ha (17.28) a (15.69) a (14.28) a (15.79) (12.68) ab (10.64) a (10.86) ab (11.12) Carbosulfan 6G 1250 g a.i. ha (17.26) a (15.60) a (13.82) a (15.62) (12.26) a (10.37) a (9.45) a (10.61) Carbosulfan 6G 1000 g a.i. ha (18.77) b (16.54) ab (15.63) b (17.02) (13.46) b (11.30) a (10.80) bc (11.91) Phorate 1000 g a.i. ha (18.89) b (17.01) b (16.70) c (17.56) (13.50) b (11.35) a (10.88) c (11.96) Untreated control (19.31) b (18.96) c (18.89) d (19.05) (19.07) c (18.94) b (18.90) d (18.97) DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in Parentheses are arc sine transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

80 observed after first application, at 7 DAA was 8.80 in carbosulfan 6G (NS) 1250 g a.i. ha -1 treated plots followed by 8.82, 10.21, 10.35, 10.41, and in carbosulfan 6G(NS) 1000 g a.i. ha -1, 750 g a.i ha -1, carbosulfan 6G (ES) 1000 g a.i. ha -1, carbosulfan 6G (NS) 600 g a.i ha -1 and phorate 10G g a.i. ha -1, respectively (Table 3). At 14 DAA, carbosulfan 6G (NS) at 1250 g a.i. ha -1 recorded the least damage of 7.23 per cent and was on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1 (7.31 %), carbosulfan 6G (ES) at 1000 g a.i. ha -1 (8.10 %). At 21 DAA, carbosulfan 6G (NS) at 1250 g a.i. ha -1, 1000 g a.i. ha -1 and 750 g a.i. ha -1 recorded 5.71, 6.08 and 6.27 per cent leaf damage and were on par with one another. All the treatments were superior over the untreated control (Table 3). The per cent leaf damage recorded after second application was significantly minimum in plots treated with carbosulfan 6G (NS) at 1250 g a.i. ha -1 on 7, 14 DAA with damage per cent of 4.51, 3.24 per cent and on 21 DAA, it was 2.42 per cent which was on par with carbosulfan 6G (NS) 1000 g a.i. ha -1 (3.72%) and carbosulfan 6G (NS) 750 g a.i. ha -1 g a.i. ha -1 (3.94 %). It was followed carbosulfan 6G (NS) 600 g a.i. ha -1 (4.11%), carbosulfan 6G (ES) 1000 g a.i. ha -1 (4.26), phorate 10G 1000 g a.i. ha -1 (4.29 %) (Table 3). In the second season, carbosulfan 6G (NS) at 1250 g a.i. ha -1 recorded the lowest per cent of 9.15 leaf damage after first application at 7 DAA followed by 9.28, 10.00, 10.56, and10.76, in carbosulfan 6G (NS) at 1000 g a.i. ha -1, 750 g a.i. ha -1, 600 g a.i. ha -1, carbosulfan 6G (ES) at 1000 g a.i. ha -1, and phorate 10G g a.i. ha -1, respectively. At 14 DAA, carbosulfan 6G (NS) at 1250 g a.i. ha -1 recorded the least damage (6.00%). At 21 DAA, carbosulfan 6G (NS) at 1250 g a.i. ha -1, carbosulfan 6G (NS) at 1000 g a.i. ha -1, 750 g a.i. ha -1 recorded 4.78, 5.12 and 5.12 per cent respectively (Table 4). After second application, the minimum leaf damage of 3.42, 3.00 and 2.42 per cent was recorded on 7, 14 and 21 DAA in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots, respectively. The trend of damage observed in other plots was similar to that of first application (Table 4). Based on the per cent reduction in leaf damage over untreated check after two applications in the two seasons, the order of efficacy of different treatments is as follows: carbosulfan 6G (NS) 1250 g a.i. ha -1 > 1000 g a.i. ha -1 > 750 g a.i. ha -1 > carbosulfan 6G (ES) at 1000 g a.i. ha -1 > carbosulfan 6G (NS) at 600 g a.i. ha -1 > phorate 10G at 1000 g a.i.ha -1.

81 Table 4: Effect of carbosulfan 6G on damage caused by leaf folder in rice (Location: PBS, TNAU, Coimbatore II season) PTC 7DAT 14DAT 21DAT Mean PR PTC 7DAT 14DAT 21DAT Mean PR Percent damage Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha (18.96) bcd (15.25) ab (14.32) c (16.29) (13.75) b (10.77) a (10.34) c (11.71) Carbosulfan 6G 750 g a.i. ha (18.43) abc (15.13) ab (13.08) ab (15.69) (13.25) b (10.64) a (10.14) bc (11.42) Carbosulfan 6G 1000 g a.i. ha (17.74) ab (14.37) a (13.08) ab (15.18) (11.71) a (10.17) a (9.15) ab (11.22) Carbosulfan 6G 1250 g a.i. ha (17.61) a (14.18) a (12.60) a (14.93) (10.66) a (9.97) a (8.95) a (11.03) Carbosulfan 6G 1000 g a.i. ha (20.75) bcd (15.63) bc (13.96) bc (16.00) (13.37) b (10.77) a (10.19) bc (11.52) Phorate 1000 g a.i. ha (19.15) cd (16.44) c (14.55) c (16.81) (13.45) b (10.88) a (10.56) c (11.70) Untreated control (19.82) d (19.60) d (19.74) d (19.72) (19.31) c (18.96) b (18.89) d (19.05) DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in Parentheses are arc sine transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

82 Rice green leafhopper The population of rice green leafhopper (nymphs and adults) was counted in ten tagged hills per plot for the first season by taking observations before first application as well as 7, 14 and 21 DAA. The population was found to be uniform in the pre treatment count ranging between 5.65 and 6.51 per hill among different experimental plots and was found to be non significant one another (Table 5). The population observed after first application on 7 DAA was the least (1.76 hill -1 ) in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots followed by 2.05, 3.25, 3.49, 3.97, 4.28, and 8.78 per hill in carbosulfan 6G (NS) at 1000 g a.i. ha -1, carbosulfan 6G (ES) at 1000 g a.i. ha -1, carbosulfan 6G (NS) at 750 g a.i. ha -1, 600 g a.i. ha -1, phorate 10G 1000 g a.i. ha -1, and untreated check plots, respectively. At 14 and 21 DAA, the green leafhopper population was found minimum in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots with a population of 2.35 and 2.56 per hill respectively compared to other treatments (Table 5). After second application, the population was observed to be the lowest in plots treated with carbosulfan 6G (NS) at 1250 g a.i. ha -1 with population of 1.19, 1.62 and 1.74 per hills on 7, 14 and 21 DAA, respectively which were on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1, (1.65, 1.72 and 1.85 hill -1, respectively) and carbosulfan 6G (ES) at 1000 g a.i. ha -1 (1.81,1.83 and 2.21 hill -1, respectively) (Table 5). In second season, the population per hill observed after first application was found to be the least (2.92) at 7 DAA in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots followed by 3.67, 3.78, 4.18, 4.74, and 5.90 in carbosulfan 6G (NS) at 1000 g a.i. ha -1, carbosulfan 6G (ES) at 1000 g a.i. ha -1, carbosulfan 6G (NS) at 750 g a.i. ha -1, 600 g a.i.ha -1, and phorate 10G at 1000 g a.i. ha -1, respectively. On 14 DAA, carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots recorded significantly the lowest (2.85 hill -1 ) and was on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1 (2.95 hill -1 ). On 21 DAA, the population in carbosulfan 6G (NS) at 1250 g a.i. ha -1 (3.75hill -1 ) and 1000 g a.i. ha -1 (4.18 hill -1 ) plots was on par (Table 6). After second application, carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plot recorded the least population count of (0.88, 1.68 and 1.81 hill -1 ) and was followed by

83 Table 6: Effect of carbosulfan 6G on population of GLH in rice (Location: PBS, TNAU, Coimbatore II season) Number population per hill Per cent Treatments I st Application 2 nd Application reduction over control PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (2.29) c (2.17) b (2.24) b (2.16) bc (2.10) b (2.15) ab (2.04) b (1.86) a (2.16) ab (1.85) a (1.83) a (2.06) a (2.07) b (2.08) b (2.20) ab (2.53) d (2.34) c (2.47) c (2.97) e (3.02) d (3.02) d (1.67) b (1.90) c (1.94) b (1.66) b (1.67) b (1.90) b (1.22) a (1.47) a (1.58) a (1.17) a (1.48) a (1.52) a (1.53) b (1.58) ab (1.62) a (1.84) c (1.95) c (1.97) b (3.10) d (3.12) d (3.13) c DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

84 carbosulfan 6G (NS) at 1000 g a.i. ha -1 (1.00, 1.65, 1.99 hill -1 ) on 7, 14 and 21 DAA, respectively compared to other treatments. The order of pest population found in different treatments were similar to that observed in first season (Table 6). Based on the per cent reduction in mean GLH population over untreated check after two applications in both seasons, the order of efficacy of different treatments is as follows: carbosulfan 6G (NS) 1250 g a.i. ha -1 > 1000 g a.i. ha -1 > carbosulfan 6G (ES) 1000 g a.i. ha -1 > carbosulfan 6G (NS) 750 g a.i. ha -1 > 600 g a.i. ha -1 > phorate 10G at 1000 g a.i. ha Rice brown planthopper In the pre treatment count, the population of BPH was found to be uniform ranging between 3.92 and 4.53 per hill among experimental plots and it was found to be non significant (Table 7). The population observed after first application on 7 DAA was the least (1.62 hill -1 ) in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots which was on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1, (1.86 hill -1 ) carbosulfan 6G (ES) at 1000 g a.i. ha -1 (2.92 hill -1 ) and carbosulfan 6G (NS) at 750 g a.i. ha -1 (3.00 hill -1 ). At 14 and 21 DAA, the BPH population found in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots recorded significantly the least population of 1.86 and 2.22 hill -1 respectively and on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1 (2.00 and 2.50 hill -1 respectively) and next in order were carbosulfan 6G (ES) at 1000 g a.i. ha -1 (2.42 and 2.70 hill -1 respectively) and carbosulfan 6G (NS) at 750 g a.i. ha -1 (2.85 and 3.15 hill -1 respectively) (Table 7). After second application also, the BPH population was found to be the least in plots treated with carbosulfan 6G (NS) at 1250 g a.i. ha -1 with population of 0.89, 1.39 and 1.56 per hills on 7, 14 and 21 DAA, respectively (Table 7). In, second season, after first application, the population of BPH, was found to be uniform in the pre treatment control which was non significant, but the population of BPH found to be least (1.65 hill -1 ) at 7 DAA in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots and was par with carbosulfan 6G (NS) at 1000 g a.i. ha -1, (1.95 hill -1 ) and carbosulfan 6G (ES) at 1000 g a.i. ha -1 (2.87 hill -1 ) followed by carbosulfan 6G (NS) at 750 g a.i. ha -1, (3.00 hill -1 ) carbosulfan 6G (NS) at 600 g a.i. ha -1 (3.13 hill -1 ),

85 Table 7: Effect of carbosulfan 6G on population of BPH in rice (Location: PBS, TNAU, Coimbatore I season) Treatments Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control 4.40 Number population per hill Per cent reduction over control I st Application 2 nd Application PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean (2.00) c (2.10) d (1.94) d (1.88) b (1.83) c (1.91) cd (1.54) a (1.58) ab (1.73) ab (1.46) a (1.54) a (1.65) a (1.85) b (1.71) b (1.79) bc (1.91) bc (2.01) d (2.12) e (2.25) d (2.42) e (2.35) f DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values (1.77) b (2.09) d (1.87) c (1.73) b (1.84) c (1.85) c (1.19) a (1.52) ab (1.62) b (1.18) a (1.37) a (1.44) a (1.30) a (1.57) b (1.64) b (1.67) b (1.95) c (2.10) d (2.65) c (2.76) e (2.88) e In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

86 phorate 10G at 1000 g a.i. ha -1, (3.48 hill -1 ), while the untreated check recorded 6.55 hill -1. On 14 and 21 DAA, the population was found to be the least in carbosulfan 6G (NS) at 1250 g a.i. ha -1 (2.06 and 3.17 hill -1 ) and was on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1 (2.28 and 3.39 hill -1 ) and carbosulfan 6G (ES) at 1000 g a.i. ha -1 (3.15 and 3.42 hill -1 ) (Table 8). After second application, carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plot recorded the least BPH population count of 0.91, 1.12 and 1.56 per hill on 7 DAA, 14 DAA and 21 DAA, respectively compared to other treatments. Based on the per cent reduction in mean BPH population over untreated check after two applications in both seasons, the order of efficacy of different treatments is as follows: carbosulfan 6G (NS) at 1250 g a.i. ha -1 > 1000 g a.i. ha -1 > carbosulfan 6G (ES) at 1000 g a.i. ha -1 > carbosulfan 6G (NS) at 750 g a.i. ha -1 >600 g a.i. ha -1 > and phorate 10G 1000 g a.i.ha Rice white backed planthopper The population of rice WBPH nymphs and adults were counted hill -1 for both the seasons by taking observations before first application as well as 7, 14 and 21 days after application (DAA). In the pre treatment count, the population was found to be uniform ranging between 3.69 and 4.51 hill -1 during first season among experimental plots and it was found to be non significant (Table 9). The population observed after first application on 7 DAA was the least (0.89 hill -1 ) in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots followed by 1.07, 1.26, 1.89, 2.12 and 3.18 in carbosulfan 6G (NS) at 1000 g a.i. ha -1, carbosulfan 6G (ES) at 1000 g a.i. ha -1, carbosulfan 6G (NS) at 750 g a.i. ha -1, 600 g a.i. ha -1 and phorate 10G 1000 g a. i. ha -1, respectively. At 14 and 21 DAA, carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots recorded the least WBPH population of 1.89 and 2.01 hill -1, respectively among all other treatments followed by carbosulfan 6G (NS) at 1000 g a.i. ha -1 (2.00 and 2.21hill -1 ), carbosulfan 6G (ES) at 1000 g a.i. ha -1 (2.06 and 2.25 hill -1 ), carbosulfan 6G (NS) at 750 g a.i. ha -1 (2.15and 2.38 hill -1 ) carbosulfan 6G (NS) at 600 g a.i. ha -1 (2.28 and 2.51 hill -1 ), and phorate 10G 1000 g a.i.ha -1 (3.28 and 3.45 hill -1 ) (Table 9). After second application, the WBPH population was found to be the least in plots treated with carbosulfan 6G (NS) at 1250 g a.i. ha -1 with a population of 0.90, 1.78 and

87 Table 8: Effect of carbosulfan 6G on population of BPH in rice (Location: PBS, TNAU, Coimbatore II season) Treatments Number population per hill Per cent reduction over control I st Application 2 nd Application PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (1.91) bc (1.99) bc (2.03) ab (1.87) b (1.94) bc (2.00) ab (1.47) a (1.60) a (1.92) a (1.57) a (1.67) a (1.97) ab (1.84) b (1.91) b (1.98) ab (1.99) c (2.04) c (2.06) b (2.66) d (2.69) d (2.70) c (1.79) b (1.87) b (1.91) c (1.77) b (1.85) b (1.87) c (1.17) a (1.35) a (1.49) ab (1.19) a (1.27) a (1.44) a (1.23) a (1.38) a (1.59) b (1.70) b (1.94) b (2.10) d (2.74) c (2.76) c (2.79) e DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

88 PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Table 9: Effect of carbosulfan 6G on population of WBPH in rice (Location: PBS, TNAU, Coimbatore I season) Number population per hill Per cent Treatments I st Application 2 nd Application reduction over control Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha (1.62) c (1.67) b (1.73) b (1.55) c (1.63) ab (1.70) ab (1.25) ab (1.58) ab (1.65) ab (1.18) a (1.55) a (1.58) a (1.59) c (1.64) b (1.86) c (1.46) b (1.59) ab (1.67) b (1.23) a (1.57) ab (1.58) ab (1.18) a (1.51) a (1.54) a Carbosulfan 6G 1000 g a.i. ha (1.33) b (1.60) ab (1.66) ab (1.26) a (1.58) ab (1.63) ab Phorate 1000 g a.i. ha Untreated control (1.92) d (1.94) c (1.99) c (2.28) e (2.28) d (2.31) d (1.87) d (1.91) c (1.99) d (2.38) e (2.40) d (2.42) e DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

89 1.86 hill -1 on 7, 14 and 21 DAA, respectively. This was on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1 (1.02, 1.96 and 2.00 hill -1 ) (Table 9). In second season, the population in pre treatment count was found to be uniform ranging between 2.89 and 3.41 per hill among experimental plots and it was found to be non significant. The population observed after first spray at 7 DAA was the least (0.67 hill -1 ) in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plots followed by 1.00, 1.57, 1.75, 1.95 and 2.15 hill -1 in carbosulfan 6G (NS) at 1000 g a.i. ha -1, carbosulfan 6G (ES) at 1000 g a.i. ha -1, carbosulfan 6G (NS) at 750 g a.i. ha -1, 600 g a.i. ha -1 and phorate 10G at 1000 g a.i.ha -1, respectively. On 14 and 21 DAA, the population in carbosulfan 6G (NS) at 1250 g a.i. ha -1 (1.71 and 1.92 hill -1 ) was followed by carbosulfan 6G (NS) at 1000 g a.i. ha -1 (1.82 and 1.98 hill -1 ) (Table 10). After second application, carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plot recorded the least WBPH population count of 0.62, 1.25 and 1.59 per hill on 7, 14 and 21 DAA, respectively. The order of pest population found in experimental plots was similar to that observed in first season (Table 10) Effect of carbosulfan 6G (NS) on natural enemies of rice ecosystem Spiders Pre treatment count of spider population varied between 7.20 to 8.90 and 7.21 to 9.00 per 5 hills in first season and second season, respectively and were found to be non significant (Table 11, and 12). During first season the spider population was recorded among the different treatments at 7, 14 and 21 DAA after each application. Among the treatments, the spider population recorded were on par each other per 5 hills in the first and second application, respectively. At 7 DAA, the spider population found in the highest dose of carbosulfan 6G (NS) at 1250 g a.i. ha -1 was 7.80 and 6.12 per 5 hills in the first and second application respectively. This was followed by carbosulfan 6G (NS) at 1000 g a.i. ha -1 (8.00 & 6.85), carbosulfan 6G (ES) at 1000 g a.i. ha -1 (7.80 & 7.10) and phorate 10G at 1000 g a.i.ha -1 (7.80 & 7.10) per 5 hills in the first and second application respectively among the test doses. Similar trend was observed on 14 and 21 DAA in both sprayings (Table 11).

90 Table10: Effect of carbosulfan 6G on population of WBPH in rice (Location: PBS, TNAU, Coimbatore II season) Number population per hill Per cent reduction over control PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha (1.57) dc (1.76) c (1.89) b (1.31) b (1.66) c (1.70) c Carbosulfan 6G 750 g a.i. ha (1.50) cd (1.66) bc (1.81) b (1.23) b (1.59) bc (1.63) bc Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha (1.22) b (1.52) a (1.57) a (1.08) a (1.49) a (1.56) a (1.20) b (1.51) b (1.57) ab (1.06) a (1.32) a (1.45) a Carbosulfan 6G 1000 g a.i. ha (1.44) c (1.57) a (1.65) a (1.22) b (1.52) b (1.58) b Phorate 1000 g a.i. ha Untreated control (1.63) e (1.87) d (2.15) c (2.18) f (2.33) e (2.33) d (1.85) c (1.90) d (1.98) d (2.34) d (2.34) e (2.35) e DAT: Days after Treatment, NS: New source, EC: Existing source, PR: Per cent reduction, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

91 Table 11: Effect of carbosulfan 6G on population of spiders in rice (Location: PBS, TNAU, Coimbatore I season) PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Number population per 5 hills Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (2.97) a (2.98) a (2.93) a (2.79) a (2.97) a (2.98) a (2.92) a (2.81) a (2.93) a (2.88) a (2.85) a (2.88) a (2.88) a (2.90) a (2.93) a (2.76) a (2.77) a (2.76) a (2.97) a (2.93) a (2.97) a (2.79) a (2.74) a (2.71) a (2.79) a (2.72) a (2.72) a (2.71) a (2.72) a (2.74) a (2.57) a (2.76) a (2.82) a (2.76) a (2.72) a (2.69) a (2.74) a (2.70) a (2.69) a (3.07) a (2.95) a (2.92) a 8.37 DAT: Days after Treatment, NS: New source, EC: Existing source, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

92 During second season, the standard check phorate 10G at 1000 g a.i.ha -1 recorded the lowest spider population among the treatments i.e and 5.92 spiders per 5 hills. Among the test doses of carbosulfan, the spider population at 7 DAA was found to be the lowest (8.10 and 6.31 five hills -1 respectively in the first and second application). Similar trend was observed in 14 DAA and 21 DAA (Table 12) Mirid bugs The pre treatment count of mirid bug population varied from 5.89 to 7.30 and 6.12 to 7.52 per 5 hills in both the seasons and was found to be non significant (Table 13 and 14). The mirid bug population recorded among the different treatments at 7, 14 and 21 DAA after each application. At 7 DAA, minimum number of mirid bugs was found in the highest dose of carbosulfan 6G (NS) at 1250 g a.i. ha -1 (4.92 and hills -1 ) in the first and second application respectively. The standard check phorate 10G at 1000 g a.i.ha -1 recorded the mirid bug population of 5.32 and 5.51bugs per 5 hills among all the treatments (Table 13). During second season, the standard check phorate 10G at 1000 g a.i.ha -1 recorded the lowest mirid bug population of 4.61 and 4.75 bugs per 5 hills in the first and second application, respectively. Among the test doses of carbosulfan, mirid bug population at 7 DAA in carbosulfan 6G (NS) at 1250 g a.i. ha -1 treated plot was (5.10 and hills -1 in the first and second application respectively). This was followed by carbosulfan 6G (NS) at 1000 g a.i. ha -1 and carbosulfan 6G (ES) at 1000 g a.i. ha -1 which recorded 4.41 & 4.55 and 4.21 &4.74 per 5 hills after the first and second application, respectively (Table 14) Rove beetle The pre treatment count of rove beetle population varied from 6.89 to 9.00 and 6.70 to 9.00 per 5 hills in first and second seasons respectively and was found to be non significant (Table 15 and 16). The rove beetle population was recorded among the different treatments at 7, 14 and 21 DAA after each application. The mean at 7, 14 & 21 DAA, minimum number of

93 Table 12: Effect of carbosulfan 6G on population of spiders in rice (Location: PBS, TNAU, Coimbatore II season) PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Number population per 5 hills Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (2.95) a (2.93)= 7.30 (2.79) a (2.88) a (2.93) a (2.85) a (2.81) a (2.89) a (2.89) a (2.93) a (2.92) a (2.82) a (2.90) a (2.95) a (2.86) a (2.79) a (2.86) a (2.90) a (2.92) a (2.95) a (2.89) a (2.64) a (2.55) a (2.68) a (2.60) a (2.69) a (2.56) a (2.66) a (2.54) a (2.57) a (2.61) a (2.52) a (2.53) a (2.68) a (2.55) a (2.53) a (2.53) a (2.51) a (2.57) a (2.64) a (2.58) a (2.68) a 6.44 DAT: Days after Treatment, NS: New source, EC: Existing source, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05

94 Table13: Effect of carbosulfan 6G on population of mirids in rice (Location: PBS, TNAU, Coimbatore I season) Number population per 5 hills PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean (2.76) a (2.52) abc (2.55) a (2.66) ab (2.57) ab (2.53) a (2.37) d (2.48) bc (2.49) a (2.45) cd (2.43) bc (2.45) a (2.45) cd (2.47) bc (2.39) a (2.45) cd (2.37) c (2.45) a (2.57) bc (2.63) a (2.53) a 6.15 Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (2.76) a (2.59) a (2.37) b (2.61) bc (2.41) a (2.43) b (2.43) de (2.48) a (2.43) b (2.33) e (2.53) a (2.37) b (2.49) cd (2.47) a (2.35) b (2.41) de (2.43) a (2.32) b (2.66) ab (2.59) a (2.65) a DAT: Days after Treatment, NS: New source, EC: Existing source, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

95 Table 14: Effect of carbosulfan 6G on population of mirids in rice (Location: PBS, TNAU, Coimbatore II season) PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Number population per 5 hills Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (2.25) a (2.49) a (2.47) a (2.19) a (2.47) a (2.49) a (2.22) a (2.45) a (2.43) a (2.37) a (2.22) a (2.43) a (2.17) a (2.49) a (2.39) a (2.26) a (2.41) a (2.35) a (2.33) a (2.52) a (2.47) a (2.35) abc (2.44) a (2.43) a (2.43) ab (2.35) a (2.37) a (2.25) c (2.46) a (2.33) a (2.34) bc (2.41) a (2.13) b (2.29) bc (2.43) a (2.33) a (2.30) bc (2.36) a (2.13) b (2.49) a (2.49) a (2.39) a 5.54 DAT: Days after Treatment, NS: New source, EC: Existing source, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

96 rove beetle was found in the highest dose of carbosulfan 6G (NS) at 1250 g a.i. ha -1 (6.84 and hills -1 in the first and second application respectively). The standard check phorate 10G at 1000 g a.i.ha -1 recorded the rove beetle population of 6.82 and 6.26 beetles per 5 hills (Table 15). During second season, the standard check phorate 10G at 1000 g a.i.ha -1 recorded the rove beetle population of 6.84 and 6.29 beetles per 5 hills in the first and second application, respectively. Among the test doses of carbosulfan, rove beetle population in carbosulfan 6G (NS) at 1250 g a.i. ha -1 (6.70 and hills -1 at 7 days after first and second application respectively) (Table 16) Yield Rice Carbosulfan 6G (NS) at 1000 g a.i. ha -1 recorded significantly higher yield of 5856 & 4665 kg ha -1 as grain and straw respectively, which was on par with carbosulfan 6G (NS) at 1250 g a.i. ha -1 (5813 & 4350 kg ha -1 ) and carbosulfan 6G (ES) at 1000 g a.i. ha -1 (5806 & 3780 kg ha -1 ). It was followed by carbosulfan 6G (NS) at 750 g a.i. ha -1 (5324 & 3875 kg ha -1 ), 600 g a.i. ha -1 (5250 & 3380 kg ha -1 ) and phorate 10G at 1000 g a.i.ha -1 (4894 & 3290 kg ha -1 ). The untreated check recorded the least yield of 4424 & 3198 kg ha -1 in first season (Table 17). During the second season also, Carbosulfan 6G (NS) at 1000 g a.i. ha -1 recorded the highest yield of 6012 & 4582 kg ha -1 as grain and straw which was on par with carbosulfan 6G (NS) at 1250 g a.i. ha -1 (5974 & 4310 kg ha -1 ), carbosulfan 6G (ES) at 1000 g a.i. ha -1 (5850 & 3675 kg ha -1 ). It was followed by Carbosulfan 6G (NS) at 750 g a.i. ha -1 (5415 & 2762 kg ha -1 ), Carbosulfan 6G (NS) at 600 g a.i. ha -1 (5205 & 3290 kg ha -1 ) and phorate 10G at 1000 g a.i.ha -1 (4935 & 3200 kg ha -1 ).The untreated check recorded the least yield of 4458 & 3109 kg ha -1 in rice grain and straw respectively (Table 18) Black gram Carbosulfan 6G (NS) at 1000 g a.i. ha -1 recorded significantly the higher yield of 432 kg ha -1 which was on par with carbosulfan 6G (NS) at 1250 g a.i. ha -1 (420 kg ha -1 ) and carbosulfan 6G (ES) at 1000 g a.i. ha -1 (400 kg ha -1 ). It was followed by carbosulfan

97 Table 15: Effect of carbosulfan 6G on population of rove beetle in rice (Location: PBS, TNAU, Coimbatore I season) PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean Number population per 5 hills Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (2.62) a (2.79) a (2.86) a (2.72) a (2.79) a (2.76) a (2.70) a (2.78) a (2.75) a (2.76) a (2.74) a (2.63) a (2.61) a (2.78) a (2.81) a (2.65) a (2.74) a (2.72) a (2.72) a (2.77) a (2.85) a (2.72) a (2.74) a (2.73) a (2.72) a (2.61) a (2.71) a (2.57) a (2.65) a (2.76) a (2.69) a (2.61) a (2.57) a (2.65) a (2.66) a (2.61) a (2.66) a (2.56) a (2.58) a (2.72) a (2.79) a (2.77) a 7.13 DAT: Days after Treatment, NS: New source, EC: Existing source, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

98 Table 16: Effect of carbosulfan 6G on population of rove beetle in rice (Location: PBS, TNAU, Coimbatore II season) Number population per 5 hills PTC 7DAT 14DAT 21DAT Mean PTC 7DAT 14DAT 21DAT Mean (2.63) a (2.61) a (2.72) a (2.59) a (2.64) a (2.69) a (2.63) a (2.64) a (2.69) a (2.61) a (2.55) a (2.68) a (2.68) a (2.55) a (2.65) a (2.56) a (2.53) a (2.72) a (2.62) a (2.65) a (2.70) a 6.65 Treatments I st Application 2 nd Application Carbosulfan 6G 600 g a.i. ha Carbosulfan 6G 750 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Carbosulfan 6G 1250 g a.i. ha Carbosulfan 6G 1000 g a.i. ha Phorate 1000 g a.i. ha Untreated control (2.75) a (2.79) a (2.65) a (2.74) a (2.71) a (2.68) a (2.76) a (2.80) a (2.59) a (2.68) a (2.69) a (2.69) a (2.77) a (2.60) a (2.69) a (2.76) a (2.77) a (2.59) a (2.86) a (2.87) a (2.68) a DAT: Days after Treatment, NS: New source, EC: Existing source, PTC: Pre treatment control Figures in the parentheses are x 0. 5 transformed values. In a column, means followed by a common letter are not significantly different by DMRT (P=0.05)

99 T1 Carbosulfan 6G (NS) ab 3380 cde T2 Carbosulfan 6G (NS) ab 3875 bc T3 Carbosulfan 6G (NS) a 4665 a T4 Carbosulfan 6G (NS) a 4350 ab T5 Carbosulfan 6G (ES) a 3780 cd T6 Phorate 10G bc 3290d e T7 Untreated control c 3198 e Table 17: Yield Particulars of Rice during first season T. No. Treatment Formulation Dose (g.a.i./ha) Grain Yield (Kg/ha) Straw Yield (Kg/ha) SEM (±) (0.05)

100 T. No. Treatment Formulation Dose (g.a.i./ha) Grain Yield (Kg/ha) Straw Yield (Kg/ha) T1 Carbosulfan 6G (NS) bc 3290 bc T2 Carbosulfan 6G (NS) abc 2762 d T3 Carbosulfan 6G (NS) a 4582 a T4 Carbosulfan 6G (NS) a 4310 a T5 Carbosulfan 6G (ES) ab 3675 b T6 Phorate 10G cd 3200 bcd T7 Untreated control d 3109 cd Table 18: Yield Particulars of Rice during second season SEM (±) (0.05)

101 6G (NS) at 750 g a.i. ha -1 (386 kg ha -1 ), carbosulfan 6G (NS) at 600 g a.i. ha -1 (364 kg ha -1 ) and phorate 10G at 1000 g a.i.ha -1 (310 kg ha -1 ). The untreated check recorded the least yield of 480 kg ha -1 in first season (Table 19). During the second season also, carbosulfan 6G (NS) at 1000 g a.i. ha -1 recorded the highest yield of 389 kg ha -1 which was on par with carbosulfan 6G (NS) at 1250 g a.i. ha -1 (375 kg ha -1 ), and carbosulfan 6G (ES) at 1000 g a.i. ha -1 (368 kg ha -1 ). It was followed by carbosulfan 6G (NS) at 750 g a.i. ha -1 (352 kg ha -1 ), carbosulfan 6G (NS) at 600 g a.i. ha -1 (336 kg ha -1 ) and phorate 10G at 1000 g a.i.ha -1 (310 kg ha -1 ). The untreated check recorded the least yield of 270 kg ha -1 (Table 20) Evaluation of phytotoxicity of carbosulfan 6G (NS) on rice The field experiments conducted at Paddy Breeding Station, TNAU, Coimbatore for two seasons to assess the phytotoxic effect of carbosulfan 6G (NS) on rice revealed that rice plants applied with carbosulfan 6 G (NS) at 1000 (x) & 2000 (2x) g a.i. ha -1 and carbosulfan 6G at 1000 (x) & 2000 (2x) g a.i. ha -1 did not show any phytotoxic effects like injury to leaf tip and leaf surface, wilting, vein clearing, necrosis, epinasty and hyponasty at 1, 3, 5,7, 13, 15, 17, 19, 23, 25, and 28 days after application in rice (Table 21 and 22) a. Evaluation of phytotoxicity of carbosulfan 6G (NS) on succeeding crop (Black Gram) The field experiments conducted at Paddy Breeding Station, TNAU, Coimbatore for two seasons to assess the phytotoxic effect of carbosulfan 6G (NS) on rice fallowed by succeeding crop (Black gram) revealed that rice plants applied with carbosulfan 6G (NS) at1000 (x) & 2000 (2x) g a.i. ha -1 and carbosulfan 6G at 1000 (x) & 2000 (2x) g a.i. ha -1 did not show any phytotoxic effects like injury to leaf tip and leaf surface, wilting, vein clearing, necrosis, epinasty and hyponasty at 1, 3, 5,7, 13, 15, 17, 19, 23, 25, and 28 days after application in black gram (Table 23 and 24).

102 T. No. Treatment Formulation Dose (g.a.i./ha) Grain Yield (Kg/ha) T1 Carbosulfan 6G (NS) b T2 Carbosulfan 6G (NS) ab T3 Carbosulfan 6G (NS) a T4 Carbosulfan 6G (NS) a T5 Carbosulfan 6G (ES) ab T6 Phorate 10G c T7 Untreated control c Table 19: Yield Particulars of black gram during first season SEM (±) (0.05) 50.20

103 T. No. Treatment Formulation Dose (g.a.i./ha) Grain Yield (Kg/ha) T1 Carbosulfan 6G (NS) bc T2 Carbosulfan 6G (NS) abc T3 Carbosulfan 6G (NS) a T4 Carbosulfan 6G (NS) ab T5 Carbosulfan 6G (ES) ab T6 Phorate 10G cd T7 Untreated control d Table 20: Yield Particulars of black gram during second season SEM (±) (0.05) 46.26

104 1. T1- Carbosulfan 6G (NS) T2- Carbosulfan 6G (NS) T5- Untreated control Table 21. Phytotoxicity symptoms of carbosulfan 6G on rice - Season I Sl no Treatments Dose g a.i. ha -1 Leaf tip injury Necrosis Wilting Phytotoxicity ratings * Vein Clearing Epinasty Hyponasty T3- Carbosulfan 6 G (ES) T4- Carbosulfan 6 G (ES)) *Observed on 1, 3, 5, 7, 13, 15, 17, 19, 23, 25 and 28 days after treatment

105 1. T1- Carbosulfan 6G (NS) T2- Carbosulfan 6G (NS) T3- Carbosulfan 6 G (ES) T4- Carbosulfan 6 G (ES)) T5- Untreated control Table 22. Phytotoxicity symptoms of carbosulfan 6G on rice - Season II Sl No Treatments Dose g a.i. ha -1 Leaf tip injury Necrosis Wilting Phytotoxicity ratings * Vein Clearing Epinasty Hyponasty *Observed on 1, 3, 5, 7, 13, 15, 17, 19, 23, 25 and 28 days after treatment

106 1. T1- Carbosulfan 6G (NS) T2- Carbosulfan 6G (NS) T3- Carbosulfan 6 G (ES) T4- Carbosulfan 6 G (ES)) T5- Untreated control Table 23. Phytotoxicity symptoms of carbosulfan 6G on succeeding crop (black gram) - Season I Sl no Treatments Dose g a.i. ha -1 Leaf tip injury Necrosis Wilting Phytotoxicity ratings * Vein Clearing Epinasty Hyponasty *Observed on 1, 3, 5, 7, 13, 15, 17, 19, 23, 25 and 28 days after treatment

107 1. T1- Carbosulfan 6G (NS) T2- Carbosulfan 6G (NS) T3- Carbosulfan 6 G (ES) T4- Carbosulfan 6 G (ES)) T5- Untreated control Table 24. Phytotoxicity symptoms of carbosulfan 6G on succeeding crop (black gram) - Season II Sl no Treatments Dose g a.i. ha -1 Leaf tip injury Necrosis Wilting Phytotoxicity ratings * Vein Clearing Epinasty Hyponasty *Observed on 1, 3, 5, 7, 13, 15, 17, 19, 23, 25 and 28 days after treatment

108 Perionyx excavatus y = x Cyprinus carpio y = 8.532x Cirrhinus mrigala y = x Table. 25 Acute toxicity of carbosulfan 6G to earthworms Organisms LC 50 (g/kg) Eudrilus eugeniae per cent fiducial limit Regression equation χ 2 at P = 0.05 UL LL y = x Table. 26 Acute toxicity of carbosulfan 6G to fishes Organisms LC 50 (ppm) 95 per cent fiducial limit UL LL Regression equation χ 2 at P = 0.05

109 Mean recovery percentage (%) Table 27. Recovery studies of Carbosulfan 6G (NS) in rice grain, husk, bran, straw and soil-first season Substrate Quantity fortified (ppm) Recovery percentage (%) Rice grain Husk Bran Straw Soil

110 Mean recovery percentage (%) Table 28. Recovery studies of Carbosulfan 6G (NS) in rice grain, husk, bran, straw and soil-second season Substrate Quantity fortified (ppm) Recovery percentage (%) Rice grain Husk Bran Straw Soil

111 4.2. Laboratory Experiments Safety of carbosulfan 6G (NS) to non target organisms Acute toxicity of Carbosulfan 6G (NS) to earthworms Eudrilus eugeniae (Kinberg) and Perionyx excavatus (Perrier) The LC 50 values of carbosulfan 6G (NS) to E. euginea and P. excavatus by artificial soil test bioassay method were 8.75 and 9.10 g kg -1 of soil, respectively (Table 24) Acute toxicity of Carbosulfan 6G (NS) to C. carpio and Cirrhinus mrigala The LC 50 of Carbosulfan 6G (NS) formulation to common carp C. carpio and Cirrhinus mrigala by static method were 125 and 133 ppm, respectively (Table 25) Residue Analysis Recovery studies The analytical method of carbosulfan 6G was standardised with the known purity standards in HPLC. Recovery studies were conducted to assess the validity of the present method and rice samples were fortified with 0.05, 0.1 and 0.5 ppm of technical grade carbosulfan (93.36% purity). The results are furnished in Table 28 and the standard chromatogram is illustrated in Fig- Recovery studies using control samples of rice (grain, straw, husk and brawn) were conducted by fortifying with known quantities of carbosulfan at three concentrations viz., 0.05, 0.1 and 0.5 ppm to find out the efficiency of analytical procedure. The recoveries ranged between and per cent for matrices with an average recovery of per cent (Table 29). Recovery studies using control samples of black gram (grain and husk) were conducted by fortifying with known quantities of carbosulfan at three concentrations viz., 0.05, 0.1 and 0.5 ppm to find out the efficiency of analytical procedure. The recoveries ranged between and per cent for matrices with an average recovery of per cent (Table 30).

112 Mean recovery percentage (%) Table 29. Recovery studies of Carbosulfan 6G (NS) in succeeding crop (black gram)-first season Substrate Quantity fortified (ppm) Recovery percentage (%) Black gram Husk

113 Mean recovery percentage (%) Table 30. Recovery studies of Carbosulfan 6G (NS) in succeeding crop (black gram)-second season Substrate Quantity fortified (ppm) Recovery percentage (%) Black gram Husk

114 Determinability The minimum level of quantification was 0.01 µg -1 for rice with a sample size of 20 g Harvest time residues of carbosulfan 6G (NS) a. Rice The terminal residues of carbosulfan applied twice at 1000 and 2000 g a.i. ha -1 were analysed after harvest. The results revealed that the residues of carbosulfan 6 G (NS) at test doses were below detectable level in rice (grain, straw, husk, bran and soil) (Table 31) b. Black gram The terminal residues of carbosulfan applied twice at different doses in rice fallowed by succeeding (black gram) crop viz., 1000 and 2000 g a.i. ha -1 were analysed after harvest. The results revealed that the residues of carbosulfan 6 G (NS) at test doses were below detectable level in black gram (grain and husk) (Table 32) c. Soil The harvest time residues of carbosulfan 6 G (NS) applied at different doses viz., 1000 and 2000 g a.i. ha -1 were analysed in the soil samples collected at the time of harvest and the results are presented in (Table 31 and 32).The results revealed that the residues of carbosulfan 6 G (NS) at test doses were below detectable level in the soil Biodiversity studies The results obtained on the various aspects of the present study conducted viz., collection and identification of arthropods and biodiversity indices in rice ecosystems are presented here Collection and identification of arthropods under rice ecosystem Arthropods collected at weekly intervals from August (2012) to December (2012) in rice field have been documented, identified to the extent of possible taxons (order, family, genus or species level) and various biodiversity indices were worked out. The survey yielded a wide array of 118 species under 113 genera, 65 families and 11 orders (Tables 33-38).

115 I season harvest Rice straw Husk Bran soil Carbosulfan 6G (NS) 1000 g a.i. ha -1 BDL BDL BDL BDL BDL Carbosulfan 6G (NS) 2000 g a.i. ha -1 BDL BDL BDL BDL BDL Carbosulfan 6 G (ES) 1000 g a.i. ha -1 BDL BDL BDL BDL BDL Carbosulfan 6 G (ES) 2000 g a.i. ha -1 BDL BDL BDL BDL BDL Carbosulfan 6G (NS) 1000 g a.i. ha -1 BDL BDL BDL BDL BDL Carbosulfan 6G (NS) 2000 g a.i. ha -1 BDL BDL BDL BDL BDL Carbosulfan 6 G (ES) 1000 g a.i. ha -1 BDL BDL BDL BDL BDL Table 31. Harvest time residue of carbosulfan 6G in rice, straw, husk, bran and soil Treatments Residue in (mg kg -1 ) II season harvest Carbosulfan 6 G (ES)) 2000 g a.i. ha -1 BDL BDL BDL BDL BDL BDL: Below detectable limit > 0.01 µg g -1.

116 Treatments Residue in (mg kg -1 ) I season harvest Grain Husk Soil Carbosulfan 6G (NS)@1000 g a.i ha -1 BDL BDL BDL Carbosulfan 6G (NS)@2000 g a.i ha -1 BDL BDL BDL Carbosulfan 6 G (ES)@1000 g a.i ha -1 BDL BDL BDL Carbosulfan 6 G (ES)@2000 g a.i ha -1 BDL BDL BDL Carbosulfan 6G (NS) 1000 g a.i. ha -1 BDL BDL BDL Carbosulfan 6G (NS) 2000 g a.i. ha -1 BDL BDL BDL Carbosulfan 6 G (ES) 1000 g a.i. ha -1 BDL BDL BDL Table 32. Harvest time residues of carbosulfan 6G (NS and ES) in succeeding crop (black gram) II season harvest Carbosulfan 6 G (ES)) 2000 g a.i. ha -1 BDL BDL BDL BDL: Below detectable limit > 0.01 µg g -1.

117 4.4. Occurrence of arthropods Arthropoda The collection yielded two classes of arthropods viz., Arachnida and Insecta, the maximum number of individuals were from class Insecta (4,019) followed by Arachnida (982). Totally, 5001 arthropods were collected from rice field (Table 34) Arachnida Under class Arachnida, Araneae (982) was the most ubiquitous (Table 34; Plates-). Totally nine families of Araneae were collected with majority of individuals falling under families Araneidae (243) Salticidae (176), Lycosidae (147), Tetragnathidae (97) and Oxyopidae (75), (Table 33). Majority of individuals under family Araneidae belonged to the genus Leucauge while under Salticidae the most common one was Plexippus. The next largest family was Lycosidae with majority of the members falling under genus Pardosa. Under Tetragnathidae, Tetragnatha was the major genus and Oxyopidae by oxyapes (Table 35) Insecta Totally 4,019 individuals of sub class Pterygota were collected (Table 37 and 38). Among the Pterygotes, the majority of individuals belonged to the division Endopterygota (Table 38) Exopterygota The Exopterygotes (1,855) were represented by six orders viz., Hemiptera, Thysanoptera, Orthoptera, Odonata, Dictyoptera, and Dermaptera in the descending order of occurrence (Table 37). Of the ten families of Hemiptera collected, majority of individuals fell under the family Cicadillidae (496) followed by Alydidae (212), Delphacide (167), Pentatomidae (123), Miridae (117), Reduviidae (43), Gerridae (25), Meenoplidae(13), Lygaeidae (04), Tingidae (01), (Table 33). Cicadellidae was represented by three genera with majority of individuals from the genus nephotettix (373), followed by Cofana (105) (Table 2). Similarly, Leptocorisa

118 Table 33. Diversity of arthropods at familial and generic level in rice ecosystem Order Family Geneus Sprayed Unsprayed Total Pardosa pseudoannulata Araneae Lycosidae (Boes. and Str.) Araneae Lycosidae Arctosa sp Araneae Oxyopidae Oxyopes javana (Thorel) Araneae Araneae Tetragnathidae Thomisidae Tetragnatha maxillosa (Thorel). Thomisus cherapunjeus (Tickdr) Araneae Linyphidae Atypena formosa (Oi) Araneae Araneae Areaneidae Areaneidae Argiope catenulata (Doleschall). Leucauge decorata (Walckenaer) Araneae Areaneidae Tetragnatha javana (Thorel) Araneae Areaneidae Neoscona sp Araneae Clubionidae Clubiona japonicola (Bosenberg) Araneae Salticidae Plexippus paykulli (Savig) Araneae Salticidae Bianor sp Araneae Salticidae Phidippus sp Araneae Salticidae Marpissa sp Araneae Corinnidae Oedignatha sp Coleoptera Coccinellidae Coccinella repanda (Thunberg) Coleoptera Coccinellidae Cryptocephalus schestidii Coleoptera Coleoptera Coccinellidae Coccinellidae Chilochorus circumdatus (Gyllenhal). Menochilus sexmaculatus (Fabricius) Coleoptera Coccinellidae Micraspis hirashimai Sasaji Coleoptera Coccinellidae Micraspis sp Coleoptera Coleoptera Coccinellidae Coccinellidae Coccinella transversalis (Fabricius) Harmonia octomaculata (Fabricius) Coleoptera Chrysomelidae Leptispa pygmaea Baly Coleoptera Chrysomelidae Cryptocephalus schestedti Fabricius Coleoptera Chrysomelidae Oulema oryzae (Kuwayama)

119 Order Family Geneus Sprayed Unsprayed Total Coleoptera Chrysomelidae Chaetocnema basalis (Baly) Coleoptera Chrysomyllidae Menolepta signata (Olivier) Coleoptera Chrysomelidae Menolepta sp Coleoptera Chrysomelidae Haltica cyanea (Weber) Coleoptera Coleoptera Chrysomelidae Carabidae Aulacophora foveicollis (Lucas) Ophionea nigrofasviata (Schmidt-Goebel) Coleoptera Staphylinidae Paederus fuscipes (Curtis) Coleoptera Bruchidae Callosobruchus sp Coleoptera Bruchidae Unidentified sp Coleoptera Curculionidae Myllocerus dentifer (Fabricius) Coleoptera Curculionidae Apion ampulum (Fabr) Coleoptera Curculionidae Balaninus bomfordi Coleoptera Cicindellidae Cicindela sp Coleoptera Cicindellidae Porthyma pardoxa Coleoptera Cicindellidae Cicindela lacticolor Coleoptera Dytiscidae Dytiscus sp Coleoptera Buprestidae Sphenoptera deducta Kerremans Coleoptera Buprestidae Sphenoptera sp Coleoptera Scarabaeidae Anomala dimidiata Hope Coleoptera Scarabaeidae Unidentified sp Coleoptera Elateridae Unidentified sp Coleoptera Cerambycidae Unidentified sp Coleoptera Lampyridae Unidentified sp Coleoptera Cetoninae Chiloloba acuta (Wiedemann) Dermptera Carcinophoridae Euborellia stali (Dohrn) Diptera Muscidae Musca sp Diptera Muscidae Stomoxys sp Diptera Tachinidae Argyrophylax nigrotibialis (Baranov) Diptera Tachinidae Miltogramma sp Diptera Tachinidae Misicira sp

120 Order Family Geneus Sprayed Unsprayed Total Diptera Tachinidae Unidentified sp Diptera Syrphidae Syrpha sp Diptera Stratiomyidae Sergus sp Diptera Ortilidae Ortils sp Diptera Schiomyzidae Sepedon sp Diptera Schiomyzidae Sciomodon sp Diptera Sarcophagidae Sarcophaga sp Diptera Calliphoridae Ochromya sp Hemiptera Reduviidae Polytoxus fuscovittatus (Stal) Hemiptera Reduviidae Acanthaspis siva Distant Hemiptera Hemiptera Gerridae Miridae Limnogonus fossarum (Fabricius). Cyrtorhinus lividipennis Reuter Hemiptera Miridae Calocoris sp Hemiptera Alydidae Leptocorisa oratorius (Fabricius) Hemiptera Pentatomidae Menida versicolor (Gmelin) Hemiptera Pentatomidae Eysarcoris sp Hemiptera Pentatomidae Pygomenida varipennis (West Hood) Hemiptera Pentatomidae Nezara viridula (Linnaaeus) Hemiptera Pentatomidae Scotinophara lurida (Burm.) Hemiptera Delphacide Nilaparvata lugens (Stal) Hemiptera Hemiptera Hemiptera Hemiptera Delphacide Cicadillidae Cicadillidae Cicadillidae Sogatella furcifera (Horvath). Nephotettix nigropictus (Stal). Nephotettix virescens (Distant). Recilia dorsalis (Motschulsky) Hemiptera Cicadillidae Cofana spectra (Distant) Hemiptera Meenoplidae Nisia nervosa (Motschulsky) Hemiptera Lygaeidae Geocoris sp Hemiptera Tingidae Stephanitis tipcus (Distant) Hymenoptera Braconidae Rhogas sp

121 Order Family Geneus Sprayed Unsprayed Total Hymenoptera Braconidae Stenobracon nicevillei (Bingham) Hymenoptera Braconidae Macrocentrus philippinensis Ashmead Hymenoptera Braconidae Cotesia (=Apanteles) angustibasis (Gahan) Hymenoptera Braconidae Apanteles sp Hymenoptera Braconidae Microplitis sp Hymenoptera Ichneumonidae Hymenoptera Ichneumonidae Hymenoptera Ichneumonidae Xanthopimpla flavolineata Cameron Temelucha philippinensis (Ashmead) Charops brachypterum Gupta Hymenoptera Ichneumonidae Unidentified sp Hymenoptera Elasmidae Elasmus sp Hymenoptera Trichogramatidae Trichogramma japanicum Ashmead Hymenoptera Mymaridae Anagrus sp Hymenoptera Formicidae Componotus compastris Hymenoptera Pteromalidae Unidentified sp Hymenoptera Formicidae Solenopsis geminata (Fabricius) Hymenoptera Apidae Apis florea Hymenoptera Apidae Apis sp Hymenoptera Vespidae Vespa cincta (Fab.) Hymenoptera Platygastridae Telenomus sp Hymenoptera Eulophidae Unidentified sp Hymenoptera Undetermined Unidentified Lepidoptera Lepidoptera Lepidoptera Lepidoptera Lepidoptera Lepidoptera Crambidae Hesperidae Hesperidae Satyridae Pyralidae Noctuidae Scirpophaga incertulus (Walker) Pelopidas mathias (Fabricius). Parnara guttata Bremer and Grey. Melanitis leda ismene Cramer. Cnaphalocoris medinalis (Guenee). Spodoptera litura (Fabricius) Lepidoptera Noctuidae Mocis frugalis (Fabricius)

122 Order Family Geneus Sprayed Unsprayed Total Mantodea Mantidae Mantis sp Odonata Odonata Odonata Coenagriidae Coenagriidae Libellulidae Agriocnemis pygmaea (Rambur). Agriocnemis femina (Brauer). Crocothemis servillia (Drury) Odonata Libellulidae Orthetrum Sabina (Drury) Odonata Libellulidae Brachythemis contaminata (Fab.) Orthoptera Acrididae Oxya sp Orthoptera Acrididae Oxya sp Orthoptera Acrididae Acrida turricata (L.) Orthoptera Acrididae Acrida sp Orthoptera Tettigonidae Acrida exaltata (Walker) Orthoptera Orthoptera Tettigonidae Gryllidae Conocephalus longipennis (de Haan) Anaxipha longipennis (Serville) Orthoptera Gryllidae Metioche vittaticollis (Stal) Orthoptera Gryllidae Thysanoptera Thripidae Euscyrtus concinnus (de Haan) Stenchaetothrips biformis (Bannall) Total

123 Class Order Total Grand total Arachnida Araneae Grand Total Table 34. Diversity of arthropods at ordinal level in rice ecosystem Insecta Exopterygota Endopterygota Dermaptera 11 Dictyoptera 22 Hemiptera 1201 Odonata Orthoptera 210 Thysanoptera 230 Coleoptera 1000 Diptera Hymenoptera 595 Lepidoptera 290

124 Table 35. Diversity of arthropods at familial and generic level in rice ecosystem Class 982 Order Family Genus Total Grant Total Areaneidae Argiope 73 Leucauge 80 Tetragnatha 53 Neoscona 37 Clubionidae Clubiona 59 Corinnidae Oedignatha 43 Linyphidae Atypena 83 Lycosidae Pardosa 78 Arctosa 69 Oxyopidae Oxyopes 75 Salticidae Plexippus 64 Bianor 33 Phidippus 38 Marpissa 47 Tetragnathidae Tetragnatha 97 Thomisidae Thomisus 53 Arachnida Araneae Insecta Dermptera Carcinophoridae Euborellia Dictyoptera Mantidae Mantis Hemiptera Alydidae Leptocorisa Cont., table Nephotettix 373 Cicadillidae Recilia 18 Cofana 105 Delphacide Nilaparvata Sogatella 105 Gerridae Limnogonus 25 25

125 Class Order Family Genus Total Grant Total Lygaeidae Geocoris Meenoplidae Nisia Miridae Cyrtorhinus 63 Calocoris 54 Menida 34 Eysarcoris 27 Pentatomidae Pygomenida 17 Nezara 25 Scotinophara 20 Reduviidae Polytoxus Acanthaspis 16 Tingidae Stephanitis Odonata Agriocnemis Coenagriidae Agriocnemis 58 Crocothemis Libellulidae Orthetrum 17 Brachythemis 18 Orthoptera Oxya Acrididae Acrida 30 Gryllidae Tettigonidae Anaxipha Cont., table Metioche 25 Euscyrtus 21 Acrida Conocephalus 31

126 Class Order Family Genus Total Grant Total Thysanoptera Thripidae Stenchaetothrips Bruchidae Callosobruchus Unidentified 11 Buprestidae Sphenoptera Sphenoptera 13 Carabidae Ophionea Cerambycidae Unidentified Cetoninae Chiloloba acuta Leptispa Cryptocephalus 25 Oulema 16 Chrysomelidae Chaetocnema 10 Menolepta 25 Haltica 162 Coleoptera Aulacophora 38 Cicindellidae Cicindela Porthyma 34 Coccinella Cryptocephalus 25 Coccinellidae Chilochorus 22 Menochilus 28 Micraspis 74 Harmonia 18 Cont., table 35 Curculionidae Myllocerus Apion 13 Balaninus 14 Dytiscidae Dytiscus Elateridae Unidentified 05 05

127 Class Cont., table 35 Order Family Genus Total Grant Total Lampyridae Unidentified Scarabaeidae Anomala Unidentified 03 Staphylinidae Paederus Calliphoridae Ochromya Muscidae Musca Stomoxys 05 Sarcophagidae Sarcophaga Schiomyzidae Sepedon Sciomodon 18 Diptera Stratiomyidae Sergus Syrphidae Syrpha Argyrophylax Tachinidae Miltogramma 45 Misicira 27 Unidentified 52 Ortilidae Ortils Apidae Apis Rhogas sp Stenobracon 02 Braconidae Macrocentrus 25 Cotesia (=Apanteles) 117 Hymenoptera Microplitis 32 Elasmidae Elasmus Eulophidae Unidentified Formicidae Componotus Solenopsis 22 Ichneumonidae Xanthopimpla 22 42

128 Class Order Family Genus Total Grant Total Temelucha 06 Charops 03 Unidentified 11 Mymaridae Anagrus Platygastridae Telenomus Pteromalidae Unidentified Trichogramatidae Trihcogramma Vespidae Vespa cincta Crambidae Scirpophaga Hesperidae Pelopidas Lepidoptera Noctuidae Parnara guttata 38 Spodoptera Mocis 12 Pyralidae Cnaphalocrocis Satyridae Melanitis Total 4889

129 oratorius (Fabricius). was the dominant species under the family Alydidae. Sogatella furcifera (Horvath). (105) was the prominent species found under the family Delphacide and Menida versicolor (Gmelin). (34), Eysarcoris sp. (27) were the dominant species under the family Pentatomidae. Cyrtorhinus lividipennis Reuter. (63) was the dominant species found under the family Miridae. Polytoxus fuscovittatus (Stal) (27) was the most frequently encountered species under the family Reduviidae. Nisia nervosa (Motschulsky) (13) was the dominant species under the family Meenoplidae, while Lygaeidae was represented by the genus Geocoris sp. (04) (Table 37). In case of order Thysanoptera, Thripidae (230) was the dominant family and represented by genus Stenchaetothrips biformis (Bannall) (230). Under order Orthoptera, Acrididae (81) was the dominant family followed by Gryllidae (76) and Tettigoniidae (53) (Table 2). Acrididae was represented by two genera. Among these, the majority of individuals collected were oxya sp. (51). Similarly, Anaxipha longipennis (Serville) (30) was most commonly collected from the family Gryllidae. Conocephalus longipennis (de Haan) (31) was the prominent species found under the family Tettigoniidae (Table 37). In case of Odonata, Agriocnemis femina (Brauer). (63) was the dominant species found under the family Coenagriidae. Crocothemis servillia (25) was the prominent species found under the family Libellulidae. In case of order Dictyoptera, 26 individuals of Mantis sp. (Mantidae) were collected. Under Dermptera, Euborellia stali (Dohrn). (22) was the most common Carcinophoridae (Table 37) Endopterygota Endopterygota (2,164) was represented by four orders viz., Coleoptera, Hymenoptera, Lepidoptera and Diptera in the descending order of occurrence (Table 34). Coleopterans were represented by 11 families with maximum number of individuals collected belonging to the family Chrysomelidae (225) followed by Coccinellidae (130), Cicindellidae (75), Carabidae (64), Curculionidae (40), (Table 33). Among Chrysomelidae, Haltica cyanea (Weber) (162) was the dominant species followed by Leptispa pygmaea Baly (43). Majority of the members of Coccinellidae

130 belonged to the genus Micraspis (74), followed by Coccinella (71). Similarly Cicindela sp. (41) was the dominant species followed by Porthyma pardoxa (34) under family Cicindellidae (Table 33). Most of the members of Carabidae belonged to the genus Ophionea (64) (Table 46). Under Curculionidae, the majority of individuals belonged to the genus Balaninus (14), followed by Myllocerus (13) (Table 2). Under Buprestidae, Sphenoptera (20) was the major genera collected. Cetoninae was represented by a single genus Chiloloba (11). (Table 35). Totally eleven families of Hymenoptera were collected (Plates). The maximum number of individuals were from Braconidae (174), followed by Formicidae (122), Mymaridae (51) and Trichogramatidae (42). The majority of individuals from Braconidae were represented by the genus Cotesia (=Apanteles) (117) followed by Microplitis (32) and Macrocentrus (25). Componotus (100) was the dominant genus collected from the family Formicidae. Anagrus (51) was the predominant genus collected from the family Mymaridae. Trichogramma (42) was the dominant genus collected from the family Trichogramatidae. Similarly, Apis (43) was the dominant genus collected from the family Apiidae. (Table 35). Lepidoptera was represented by five families with majority of individuals collected falling under Crambidae (94) followed by Hesperidae (91), Noctuidae (37), Pyralidae (34), Satyridae (34) (Table 35). Family Crambidae was represented by majority of individuals being Scirpophaga incertulas (Walker) (94). Similarly Pelopidas mathias (Fabricius) (53) was the most common species found under the family Hesperidae. Spodoptera litura (Fabricius ) (25), was the most dominant species found under the family Noctuidae. Pyralidae was represented by Cnaphalocrocis medinalis (Guenee) (34). Melanitis leda ismene Cramer (34), was the most common species found under the family Satyridae (Table 35) Dipterans were represented by eight families viz., Tachinidae (160), Schiomyzidae (34), Stratiomyidae (21), Ortilidae (18), Muscidae (16), Sarcophagidae (12), Syrphidae (11) and Calliphoridae (7) in the descending order of occurrence (Table 35; Plate -). Tachinidae was represented by the genus Miltogramma (45) fallowed by Argyrophylax (36), Misicira (27). Similarly, Sciomodon sp. (18) was the most common species

131 collected under the family Schiomyzidae. Among the Stratiomyidae, majority of individuals collected were Sergus sp. (21), while under Ortilidae 18 individuals belonging to the species Ortils sp.were collected. Similarly,11 individuals of Stomoxys sp. were collected under the family Muscidae. Sarcophaga sp. (5) was the dominant species collected under the family Sarcophagidae (Table 33) Diversity of arthropods in rice ecosystem Diversity of arthropods in rice field was presented in tables 3, 4 and 5. The collection yielded two classes of arthropods viz., Arachnida and Insecta in rice field. The maximum number of individuals was from class Insecta followed by Arachnida in rice ecosystem Arachnida Majority of individuals from Arachnida fell under Araneae (Table 45). The major families represented under order Araneae belonged to Araneidae, Salticidae, Lycosidae, Tetragnathidae and Oxyopidae (Table 36). Leucauge decorate, Argiope catenulata (Doleschall) and Tetragnatha javana (Araneidae), Plexippus paykulli, Phidippus sp. and Bianor sp. (Salticidae), Pardosa pseudoannulata (Boes. and Str.) and Arctosa sp (Lycosidae), Tetragnatha maxillosa (Thorel) (Tetragnathidae) and Oxyopes javana (Oxyopidae) were common in rice ecosystem (Table 36) Insecta Exopterygota Under Exopterygota, six insect orders were represented from rice field, with majority of individuals falling under order Hemiptera (1201), Thysanoptera (230), Orthoptera (210), Odonata (181), Dictyoptera (22), and Dermaptera (11) in the descending order of occurrence (Table 33). Totally 10 families of Hemipterans were collected with the majority of individuals falling under the family Cicadillidae followed by Alydidae, Delphacide, Pentatomidae, Miridae, Reduviidae, Gerridae, Meenoplidae, Lygaeidae, Tingidae in rice ecosystems (Table 33).

132 Marpissa sp. Clubiona japonicola (Bosenberg). Arctosa sp. Plate 8. Arthropods observed in Rice ecosystem (Order: Araneae)

133 Plexippus paykulli Female (Savig). Plexippus paykulli Male (Savig). Thomisus cherapunjeus (Tickdr). Plate 9. Arthropods observed in Rice ecosystem (Order: Araneae)

134 Tetragnatha javana (Thorel). Arctosa sp. Plate 10. Arthropods observed in Rice ecosystem (Order: Araneae)

135 Phidippus sp. Oxyopes javana (Thorel). Paradosa pseudoannulata (Boes. and Str.) Oedignatha sp. Plate 11. Arthropods observed in Rice ecosystem (Order: Araneae)

136 Menida sp. Menida versicolor (Gmelin). Eysarcoris sp. Pygomenida varipennis (West Hood). Scotinophara lurida (Burm). Plate 12. Arthropods observed in rice ecosystems (Order: Hemiptera)

137 Acanthaspis siva Distant. Limnogonus fossarum (Fabricius). Cyrtorhinus lividipennis Reuter. Calocoris sp. Nephotettix nigropictus (Stal). Nephotettix virescens (Distant). Plate 13. Arthropods observed in rice ecosystems (Order: Hemiptera)

138 Sogatella furcifera (Horvath) Nilaparvata lugens (Stal) Recilia dorsalis (Motschulsky) Cofana spectra (Distant) Plate 14. Arthropods observed in rice ecosystems (Order: Hemiptera)

139 Eggs Nymph Adult Chaffy panicle Plate 15. Arthropods observed in rice ecosystems (Leptocorisa oratorius (Fabricius).

140 Oxya sp1. Oxya sp. Conocephalus longipennis (de Haan) Acrida sp. Plate 16. Arthropods observed in rice ecosystems (Order: Orthoptera)

141 Orthetrum sp. Brachythemis contaminata (Fab.) Crocothemis servillia (Drury) Orthetrum Sabina (Drury) Agriocnemis femina (Brauer). Plate 17. Arthropods observed in rice ecosystems (Order: Odonata)

142 Table 36. Diversity of arthropods at familial, generic and species level in rice ecosystem (Class: Arachnida) Class Order Family Species Sprayed Unsprayed Total Arachnida Araneae Areaneidae Argiope catenulata (Doleschall) Leucauge decorata Tetragnatha javana Neoscona sp Clubionidae Clubiona japonicola Corinnidae Oedignatha sp Linyphidae Atypena formosa (Oi) Lycosidae Pardosa pseudoannulata (Boes. and Str.) Arctosa sp Oxyopidae Oxyopes javana Salticidae Plexippus paykulli Bianor sp Phidippus sp Marpissa sp Tetragnathidae Tetragnatha maxillosa (Thorel) Thomisidae Thomisus cherapunjeus Total

143 In case of order Orthoptera, family Acrididae was the most prevalent family followed by Gryllidae and Tettigoniidae. Acrididae was represented by two genera, among these, the majority of individuals collected was oxya sp from rice field. Similarly, species Anaxipha longipennis (Serville) was the most commonly collected from the family Gryllidae with maximum population from rice field. Under Dictyoptera, Mantis sp was the dominant family Mantidae (Table 35). In the case of order Thysanoptera, 230 individuals of Stenchaetothrips biformis (Bannall) (Thripidae). Two families represented under the order Odonata were Coenagrionidae and Libellulidae (Table 33). Members of family Libellulidae and Coenagrionidae. Under Dermaptera, the family Carcinophoridae was represented by the species Euborellia stali (Dohrn) were collected only from rice field (Table 37) Endopterygota Under Endopterygota four orders were collected from rice field. Among these, Coleoptera were the most common with 1000 individuals followed by Hymenoptera (595), Lepidoptera (290), and Diptera (279) in the descending order of occurrence (Table 33). Under order Coleoptera, 14 families were encountered with majority of individuals belonging to the family Chrysomelidae followed by Coccinellidae, Cicindellidae, Staphylinidae, Carbidae, Curculionidae, Dytiscidae, Buprestidae, Bruchidae, Elateridae, Cerambycidae, Cetoniidae, Scarabaeidae, and Lampyridae. in rice field (Table 38). Eleven families of Hymenoptera were collected, the maximum number of individuals falling under Braconidae followed by Formicidae, Mymaridae, and Trichogramatidae. Majority of individuals collected were Cotesia (=Apanteles) angustibasis (Gahan) most dominant species in the family Braconidae. Componotus compastris most predominant species in the family formicidae. Apis sp. the prominent species collected from the family Apidae was present in rice field. Similarly, Xanthopimpla flavolineata Cameron was dominant under the family Ichneumonidae. Under family Mymaridae, genus Anagrus was mostly found in rice field (Table 38).

144 Menochilus sexmaculatus (Fabricius). Chilochorus circumdatus (Gyllenhal). Dytiscus sp. Coccinella repanda (Thunberg). Cicindela lacticolor Ophionea nigrofasviata (Schmidt-Goebel). Plate 18. Arthropods observed in rice ecosystems (Order: Coleoptera)

145 Myllocerus dentifer (Fabricius) Apion ampulum (fabr) Balaninus bomfordi Unidentified sp1. Unidentified sp2. Plate 19. Arthropods observed in rice ecosystems (Order: Coleoptera)

146 Sepedon sp. Sciomodon sp. Haltica cyanea (Weber). Cryptocephalus schestidti Fabricius. Unidentified sp. Chiloloba acuta (Wiedemann). Plate 20. Arthropods observed in rice ecosystems (Order: Diptera and Coleoptera)

147 Larva Pupa Adult White ear symptom Plate 21. Arthropods observed in Rice ecosystem Scirpophaga incertulus (Walker).

148 Damaging symptom Larvae Adult Plate 22. Arthropods observed in Rice ecosystem Cnaphalocor is medinalis (Guenee)

149 Vespa cincta Vespa sp. Componatus compastris Unidentified sp. Apis florea Apis sp1 Plate 23. Arthropods observed in rice ecosystems (Order: Hymenoptera)

150 Apis sp 2. Apis sp 3. Stenobracon nicevillei (Bingham). Rhogas sp. Unidentified sp. Unidentified sp. Plate 24. Arthropods observed in rice ecosystems (Order: Hymenoptera)

151 Unidentified sp. Unidentified sp. Microplitis sp. Unidentified sp. Unidentified sp. Unidentified sp. Plate 25. Arthropods observed in rice ecosystems (Order: Hymenoptera)

152 Table 37. Diversity of arthropods at familial, generic and species level in rice ecosystem (Sub class: Exopterygota) Class Order Family Species Sprayed Unsprayed Total Insecta Dermptera Carcinophoridae Euborellia stali (Dohrn) Dictyoptera Mantidae Mantis sp Hemiptera Cont., table 37 Alydidae Leptocorisa oratorius (Fabricius) Nephotettix nigropictus (stal) Cicadillidae Nephotettix virescens (Distant) Recilia dorsalis (Motschulsky) Cofana spectra (Distant) Delphacide Nilaparvata lugens (stal) Sogatella furcifera (Horvath) Gerridae Limnogonus fossarum (Fabricius) Lygaeidae Geocoris sp Meenoplidae Nisia nervosa (Motschulsky) Miridae Cyrtorhinus lividipennis Reuter Calocoris sp Menida versicolor (Gmelin) Eysarcoris sp Pentatomidae Pygomenida varipennis (West Hood) Nezara viridula (Linnaaeus) Scotinophara lurida Reduviidae Polytoxus fuscovittatus (Stal) Acanthaspis siva Tingidae Stephanitis tipcus Odonata Agriocnemis pygmaea (Rambur) Coenagriidae Agriocnemis femina (Brauer) Libellulidae Crocothemis servillia Orthetrum Sabina (Drury)

153 Class Order Family Species Sprayed Unsprayed Total Brachythemis contaminata (Fab.) Orthoptera Oxya sp Acrididae Oxya sp Acrida turricata Acrida sp Anaxipha longipennis (Serville) Gryllidae Metioche vittaticollis (Stal) Euscyrtus concinnus (de Haan) Tettigonidae Acrida exaltata (Walker) Conocephalus longipennis (de Haan) Thysanoptera Thripidae Stenchaetothrips biformis (Bannall) Total

154 Table 38. Diversity of arthropods at familial, generic and species level in rice ecosystem (Sub class: Endopterygota) Class Cont., table 38 Order Family Species Sprayed Unsprayed Total Insecta Coleoptera Callosobruchus sp Bruchidae Unidentified sp Buprestidae Sphenoptera deducta Sphenoptera sp Carabidae Ophionea nigrofasviata (Schmidt-Goebel) Cerambycidae Unidentified sp Cetoninae Chiloloba acuta Leptispa pygmaea Baly Cryptocephalus schestedti Fabricius Oulema oryzae (Kuwayama) Chrysomelidae Chaetocnema basalis (Baly) Menolepta signata (Olivier) Menolepta sp Haltica cyanea (Weber) Aulacophora foveicollis (Lucas) Cicindela sp Cicindellidae Porthyma pardoxa Cicindela lacticolor Coccinella repanda Cryptocephalus schestidii Chilochorus circumdatus Coccinellidae Menochilus sexmaculatus Micraspis hirashimai Sasaji Micraspis sp Coccinella transversalis (Fabricius)

155 Class Order Family Species Sprayed Unsprayed Total Harmonia octomaculata (Fabricius) Myllocerus dentifer (Fabricius) Curculionidae Apion ampulum (Fabr) Balaninus bomfordi Dytiscidae Dytiscus sp Elateridae Unidentified sp Lampyridae Unidentified sp Anomala dimidiata Hope Scarabaeidae Unidentified sp Staphylinidae Paederus fuscipes (Curtis) Diptera Calliphoridae Ochromya sp Hymenoptera Muscidae Cont., table 38 Musca sp Stomoxys sp Sarcophagidae Sarcophaga sp Schiomyzidae Sepedon sp Sciomodon sp Stratiomyidae Sergus sp Syrphidae Syrpha sp Argyrophylax nigrotibialis (Baranov) Tachinidae Miltogramma sp Misicira sp Unidentified sp Ortilidae Ortils sp Apidae Apis florea Apis sp Rhogas sp Braconidae Stenobracon nicevillei (Bingham) Macrocentrus philippinensis Ashmead Cotesia (=Apanteles) angustibasis (Gahan)

156 Class Order Family Species Sprayed Unsprayed Total Apanteles sp Microplitis sp Elasmidae Elasmus sp Eulophidae Unidentified Formicidae Componotus compastris Solenopsis geminata (Fabricius) Xanthopimpla flavolineata Cameron Temelucha philippinensis Ichneumonidae (Ashmead)? Charops brachypterum Gupta Unidentified sp Mymaridae Anagrus sp Platygastridae Telenomus sp Pteromalidae Unidentified sp Trichogramatidae Trichograma japanicum Vespidae Vespa cincta Lepidoptera Crambidae Scirpophaga incertulus (Walker) Hesperidae Pelopidas mathias (Fabricius ) Noctuidae Parnara guttata Bremer and Grey Spodoptera litura (Fabricius ) Mocis frugalis (Fabricius) Pyralidae Cnaphalocrocis medinalis (Guenee) Satyridae Melanitis leda ismene Cramer Total

157 Dipterans were represented by eight families viz., Tachinidae, Schiomyzidae, Stratiomyidae, Ortilidae, Muscidae, Sarcophagidae, Syrphidae and Calliphoridae (Table 2). Families Tachinidae and Schiomyzidae were dominated by the genus Miltogramma and Sciomodon respectively with the highest numbers observed in rice. (Table 38). Lepidoptera was made up of five families with most of the collected individuals belonging to Crambidae. Family Hesperidae was represented by two genera with majority being Pelopidas mathias (Fabricius ) (53). Family Noctuidae was represented by two genera with majority being Spodoptera litura (Fabricius). Families Pyralidae and Satyridae were represented by single species each viz., Cnaphalocrocis medinalis (Guenee) and Melanitis leda ismene Cramer. respectively (Table 38) Biodiversity index From the collection, 11 orders of arthropods were documented. Based on this primary arthropod data, two different sets of indices namely alpha diversity indices and beta diversity indices were calculated Alpha diversity indices at ordinal, familial and species level Species richness indices Species number The species number calculated based on ordinal level varied between a minimum of four during the fourth week of December to maximum of 11 during first week of October in rice in sprayed field. On the contrary, in unsprayed field, the minimum of four during fourth week of December to maximum of 11 during first and third week of October in rice unsprayed field was recorded. Analysis of data based on familial level revealed that index value peaked in the fourth week of August (41) in sprayed rice field and lowest in the fourth week of December (10). In case of unsprayed field index value peaked in the fourth week of August (48) and lowest in the fourth week of December (13) On the generic level it was found that the index value was maximum in the fourth week of August (54) in unsprayed field and lowest in the fourth week of December (15).

158 It was maximum in the third week of October (64) and lowest in the first week of August (9) in the unsprayed field. On the species level, in rice, the index value varied between a minimum of 12 in the last week of December to a maximum of 40 in the first week of December in sprayed field. The index value was minimum 6 in the first week of August to a maximum of 40 in the fourth week of September and first week of December in unsprayed field (Table 39) Fisher s Index Based on ordinal level analysis, the Fisher s index value fluctuated between a maximum of during the second week of November and minimum of during the fourth week of December in sprayed rice field. In case of unsprayed field, maximum of during the fourth week of October and minimum of during the fourth week of December were recorded. At the familial level, the value was maximum in the fourth week of December (28.233) and minimum in the first week of August (9.430) in sprayed field. However in unsprayed field the value was maximum in the fourth week of December (25.267) and minimum in the first week of August (10.650). At species level, Fisher s index ranged between in the second week of December and 6.00 in first week of August in sprayed field. In case of unsprayed field, the index ranged between 6.00 in the first week of August and 1.04 in the fourth week of October (Table 40) Margelef D index From table 36, it could be seen that Margelef D value based on ordinal diversity varied between a minimum of in the fourth week of December and maximum of in the third week of September in sprayed field. Similarly, In case of unsprayed field a minimum of in the fourth week of December and maximum of in the third week of September was observed. Analysis of data based on family revealed the maximum value during the fourth week of August (7.678) in sprayed field. In unsprayed field the maximum values were observed in the fourth week of August (8.721).

159 Table 39. Arthropod diversity in rice ecosystem Alpha diversity (Species number) Species richness indices (Species number) Month August September Sampling weekly Ordinal level Sprayed field Familial level Generic level Species level Ordinal level Unsprayed field Familial level Generic level Species level First week Second week Third week Fourth week First week Second week Third week Fourth week First week October Second week Third week Fourth week First week November Second week Third week Fourth week First week December Second week Third week Fourth week

160 Table 40. Arthropod diversity in rice ecosystem Alpha diversity (Fishers alpha) Species richness indices (Fishers alpha) Month August Sampling weekly Ordinal level Sprayed field Familial level Generic level Species level Ordinal level Unsprayed field Familial level Generic level Species level First week E E E+06 Second week E E+01 Third week E E+01 Fourth week E E+01 September First week E E+01 Second week E E+01 Third week E E+01 Fourth week E E+01 First week E E+01 October Second week E E+01 Third week E E+01 Fourth week E E+01 First week E E+01 November Second week E E+01 Third week E E+01 Fourth week E E+01 First week E E+01 December Second week E E+01 Third week E E+01 Fourth week E E+01

161 Based on species level, the index ranged between (first week of August) and (fourth week of September) in sprayed field. While in unsprayed field the index value was the highest in the first week of December (8.250) and the lowest in the first week of August (2.791) (Table 41) Q statistic Analysis of data using Q statistic is presented in table 37. The Index value based on ordinal level was maximum in the first week of September (9.865) and minimum in the fourth week of December (0.923) in sprayed field. In case of unsprayed field, the index varied between a minimum of in the fourth week of December and a maximum of in the third week of September. On the familial level, the value was maximum in the fourth week of August (15.474) and minimum in the third week of August (9.738) in sprayed field. However, in unsprayed field, index value was highest in the fourth week of August (20.936) and lowest in the first week of August (8.656). At the species level, Q statistic value varied between a minimum of in the fourth week of December to a maximum of during the first week of December in sprayed field. In unsprayed field, the index was highest in the third week of October (20.936) and lowest during the fourth week of December (8.656) (Table 42) Brillouin s index From table 43, it could be seen that Brillouin s index value based on ordinal level fluctuated between a maximum of in the second week of November and a minimum of in the fourth week of December in sprayed field. In unsprayed field, the value was the highest during the third week of September (2.020). On familial level, the index varied between a minimum of during the fourth week of December and maximum of during the fourth week of August in sprayed field. In unsprayed field, the index varied between in the first week of August and in the fourth week of August. Analysis based on species showed that the value fluctuated between in the first week of August and in the first week of December in sprayed field.

162 Table 41. Arthropod diversity in rice ecosystem Alpha diversity (Margalef s D) Species richness indices (Margalef s D) Month August September October November December Sampling weekly Ordinal level Sprayed field Familial level Generic level Species level Ordinal level Unsprayed field Familial level Generic level Species level First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week

163 Table 42. Arthropod diversity in rice ecosystem Alpha diversity (Q Statistic) Month August September October November December Sampling weekly First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week Species richness indices (Q Statistic) Sprayed field Unsprayed field Ordinal level Familial level Generic level Species level Ordinal level Familial level Generic level Species level

164 Table 43. Arthropod diversity in rice ecosystem Alpha diversity (Brillouin diversity index) Month August September October November December Sampling weekly First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week Species richness indices (Brillouin diversity index) Sprayed field Unsprayed field Ordinal level Familial level Generic level Species level Ordinal level Familial level Generic level Species level

165 In unsprayed field, the value varied between (first week of August) and (first week of December (Table 43) Shannon Weiner index The Shannon-Weiner index calculated based on ordinal, familial and species levels is presented in table 44. It could be seen that maximum value on ordinal level was observed during the second week of November (2.118) and minimum in the fourth week of December (0.734) in sprayed field. However, in case unsprayed field, the value varied between (fourth week of December) and (third week of September). With reference to familial level, the index value fluctuated between in the first week of August and in the fourth week of August in sprayed field. In unsprayed field, the diversity value was the highest in the fourth week of August (3.624) and lowest in the first week of August (2.268). In species level, the maximum was observed in the first week of December (3.441) and minimum in first week of august (1.792) in sprayed and unsprayed field respectively (Table 44) Dominance indices Simpson s index The Simpson s index calculated based on ordinal level revealed a maximum of in the third week of September and a minimum of in the fourth week of December in sprayed field. In unsprayed field, it varied between in fourth week of December and in first week of September. On the familial level, Simpson s index varied between a maximum of in the fourth week of December and a minimum of in the first week of August in sprayed field. In unsprayed field, the index value varied between in the first week of August and in the fourth week of December. However, Simpson s index (species level) varied between a minimum of in the first week of August and a maximum of in the fourth week of December in sprayed field. In unsprayed field too, it fluctuated between in the first week of August and in the fourth week of December (Table 45).

166 Table 44. Arthropod diversity in rice ecosystem Alpha diversity (Shannon- Weiner index) Month August September October November December Sampling weekly First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week Species richness indices (Shannon- Weiner index) Sprayed field Unsprayed field Ordinal level Familial level Generic level Species level Ordinal level Familial level Generic level Species level

167 Table 45. Arthropod diversity in rice ecosystem Alpha diversity (Simpson s index) Month August September October November December Sampling weekly First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week Species dominance indices (Simpson s index) Sprayed field Unsprayed field Ordinal level Familial level Generic level Species level Ordinal level Familial level Generic level Species level

168 McIntosh index Analysis following McIntosh index of ordinal, familial and species level in the three situations is presented in table 46. On ordinal level, it fluctuated between a minimum of in the fourth week of December and a maximum of during the third week of September in sprayed field. In unsprayed field, the index value varied between (fourth week of December) and (first week of September). On family level, McIntosh index fluctuated between during the second week of December and during the fourth week of December in sprayed field. In unsprayed field, the index value varied between (first week of August) and (fourth week of December). McIntosh diversity index of species in sprayed field varied between in the fourth week of August and in the first week of August. In unsprayed field, maximum value was observed during the first week of August (1.000) and minimum in the fourth week of October (0.768) (Table 46) Berger Parker index The Berger parker index value (ordinal level) varied between in the third week of November and in the fourth week of December in sprayed field. In unsprayed field, it varied between a minimum of in the third week of November and maximum of in the fourth week of December. On the familial level, the index valued varied between in the fourth week of August to in the second week of December in sprayed field. In unsprayed field, the maximum index value was observed in third week of December (0.231) and minimum in the fourth week of August (0.055). The species level index value varied between a maximum of in the second week of August and minimum of in the second week of December in sprayed field. In unsprayed field, index value was highest in the fourth week of October (0.188) and lowest in the first week of October (0.075) (Table 47).

169 Table 46. Arthropod diversity in rice ecosystem Alpha diversity (McIntosh index) Month August Species dominance indices (McIntosh index) Sampling Sprayed field Unsprayed field weekly Ordinal Familial Generic Species Ordinal Familial Generic Species level level level level level level level level First week Second week Third week Fourth week First week September Second week Third week Fourth week First week October Second week Third week Fourth week First week November Second week Third week Fourth week First week December Second week Third week Fourth week

170 Table 47. Arthropod diversity in rice ecosystem Alpha diversity (Berger Parker diversity index) Month August Species dominance indices (Berger parker diversity index) Sampling Sprayed field Unsprayed field weekly Ordinal Familial Generic Species Ordinal Familial Generic Species level Level level level level level level level First week Second week Third week Fourth week First week September Second week Third week Fourth week First week October Second week Third week Fourth week First week November Second week Third week Fourth week First week December Second week Third week Fourth week

171 Evenness index Equitability J Ordinal level analysis indicated that the value of J varied between a minimum of in the fourth week of December and a maximum of in the third week of September in sprayed field. In unsprayed field, the index value ranged between a minimum of in the first week of August and a maximum of in the fourth week of August. With reference to family, the index value fluctuated between in the fourth week of December and in the fourth week of August in sprayed field. In unsprayed field, it varied between in the first week of August and in the fourth week of August. Based on species level, the index value ranged between in the first week of August and in the first week of December in sprayed field. While in unsprayed field, the index value was highest in the first week of December (0.731) and lowest in the first week of August (0.380) (Table 48) Beta diversity indices at ordinal, genus, familial and species level In the current study of beta diversity indices, Whittaker B w, Cody B c, Routledge B r, Routledge B i, Routledge B e and Wilson and Shmida B t indices were used to compare the species composition of different communities in the rice ecosystem. Analysis based on Whittaker B w revealed that variation in sprayed field (0.33) and unsprayed field (0.27) in ordinal level existed. In familial level, variation in sprayed field (1.31) when compared to unsprayed field (0.94) was noticed. In species level, variation was observed between sprayed field (1.84) and unsprayed field (1.77) (Table 49). Comparison based on ordinal level according to Cody B c index value, it was found that sprayed and unsprayed field diversity (6.00) only. At family level, sprayed field recorded the index value of 52.50, and unsprayed field index value of At species level, sprayed field recorded the index value of and in unsprayed field index value of was recorded (Table 49).

172 Table 48. Arthropod diversity in rice ecosystem Alpha diversity (Equitability J) Month August September October November December Sampling weekly First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week First week Second week Third week Fourth week Evenness indices (Equitability J) Sprayed field Unsprayed field Ordinal level Familial level Generic level Species level Ordinal level Familial level Generic level Species level \

173 Table 49. Arthropod diversity in rice ecosystem Beta diversity. Beta diversity index Ordinal level Sprayed field Familial level Generic level Species level Ordinal level Unsprayed field Familial level Generic level Species level Whittaker Bw Cody Bc Routledge Br Routledge Bi Routledge Be Wilson & Shmida Bt

174 Table 50. Values of similarities recorded between families of Araneae in rose using Bray-curtis per cent similarity Araneae Areaneidae Clubionidae Corinnidae Linyphidae Lycosidae Oxyopidae Salticidae Tetragnathidae Thomisidae Areaneidae Clubionidae * Corinnidae * * Linyphidae * * * Lycosidae * * * * Oxyopidae * * * * * Salticidae * * * * * * Tetragnathidae * * * * * * * Thomisidae * * * * * * * *

175 Table 51. Values of similarities recorded between families of Hemiptera in rose using Bray-curtis per cent similarity Hemiptera Alydidae Cicadillidae Delphacide Gerridae Lygaeidae Meenoplidae Miridae Pentatomidae Reduviidae Tingidae Alydidae Cicadillidae * Delphacide * * Gerridae * * * Lygaeidae * * * * Meenoplidae * * * * * Miridae * * * * * * Pentatomidae * * * * * * * Reduviidae * * * * * * * * Tingidae * * * * * * * * *

176 Table 52. Values of similarities recorded between families of Coleoptera in rose using Bray-curtis per cent similarity Bruchidae Cerambycidae * * * Cetoninae * * * * Chrysomelidae * * * * * Cicindellidae * * * * * * Coccinellidae * * * * * * * Curculionidae * * * * * * * * Elateridae * * * * * * * * * Lampyridae * * * * * * * * * * Scarabaeidae * * * * * * * * * * * Coleoptera Bruchi dae Bupresti dae Carabi dae Cerambyci dae Cetonin ae Chrysomeli dae Cicindelli dae Coccinelli dae Curculioni dae Elaterid ae Lampyri dae Scarabaei dae Buprestidae * Carabidae * *

177 Table 53. Values of similarities recorded between families of Hymenoptera in rose using Bray-curtis per cent similarity Trichogra matidae Apidae Braconidae * Elasmidae * * Eulophidae * * * Formicidae * * * * Ichneumonidae * * * * * Mymaridae * * * * * * Platygastridae * * * * * * * Pteromalidae * * * * * * * * Trichogra matidae * * * * * * * * * Vespidae * * * * * * * * * * Vespi dae Hymenoptera Apidae Braconidae Elasmidae Eulophidae Formicidae Ichneu monidae Mymari dae Platygastri dae Pteromali dae

178 Analysis based on ordinal level, using Routledge B r index revealed the maximum in sprayed field. At family and species level also, the maximum value was observed in sprayed field. Comparison based on ordinal level and familial level according to Routledge B i and Routledge B e, it was concluded that sprayed field recorded the highest index value among both fields studied (Table 49).

179 CHAPTER V DISCUSSION Indiscriminate use of insecticides, resistance development by insects and ill effects posed on environment, have opened the new era of chemicals safer to environment and having novel mode of action with higher bioefficacy against target insects. One of the new source of insecticide is carbosulfan 6G belonging to the group, carbamate. This group showed increased efficacy against rice pests and were relatively safe to non target organisms. Hence, detailed investigation were carried out with this insecticide during first season (November ) and second season (August ) at the Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore. The results on the evaluation of bioefficacy of carbosulfan 6G against rice pests, phytotoxicity, safety to natural enemies, impact on arthropod biodiversity, harvest time residues in rice (grain, husk, bran, straw and soil) and its effects on succeeding crop (black gram) are discussed in this chapter Field Experiments Bioefficacy of carbosulfan 6G (NS) against insect pests of rice Stem borer The results obtained from the field experiments of two seasons revealed that the carbosulfan 6G (NS) at 1250 g a.i. ha -1 was effective against rice stem borer and was on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1, carbosulfan 6G (NS) at 750 g a.i. ha -1 as well as carbosulfan 6G (ES ) at 1000 g a.i. ha -1. Its efficacy was found to be better than the standard check phorate 10G 1000 g a.i. ha -1. The order of efficacy of treatments in recording per cent reduction of dead heart and white ear was, carbosulfan 6G (NS) at 1250 g a.i. ha -1, carbosulfan 6G (NS) at 1000 g a.i. ha 1, carbosulfan 6G (NS) at 750 g a.i. ha -1, carbosulfan 6G (NS) at 600 g a.i. ha -1, carbosulfan 6G (ES) at 1000 g a.i. ha -1, phorate 10G 1000 g a.i. ha -1 and untreated check. These results are in accordance with (Karthikeyan and Purshothaman, 2000) who found that carbosulfan 6G at 1000 g a.i. ha -1 applied for the management of the rice stem

180 borer, resulted in per cent reduction in dead heart and per cent reduction in white ear with a significant increase in grain yield by 31.4 per cent over control. Baruah et al. (2008) reported that carbosulfan 20 EC at 350 g a.i ha -1 recorded the lowest stem borer incidence in rice than the lower doses at 250 and 300 g a.i ha -1. Similar results were reported by Hugar et al. (2009) that carbosulfan at 1000 g a.i. ha -1 applied at 50 days after sowing in aerobic rice reduced the dead heart incidence to 5.49 per cent which was significantly lower than the control (15.2 %). Krishnaiah et al., (2003) reported that carbosulfan (1 kg a.i. ha -1 ) was as effective as check insecticide carbofuran (1 kg a.i. ha -1 ) against the rice stem borer. Jena (2004) also found that seedling root dip with carbosulfan (0.02%) and fipronil (0.01%) was effective against rice yellow stem borer under field conditions. Singh et al., (1996) also reported that application of carbosulfan 3G at 1 kg a.i. ha -1 followed by monocrotophos 0.5 kg a.i. ha -1 gave effective protection against yellow stem borer and recorded minimum incidence of 2.35 to 4.13 per cent dead heart than all other treatments tested (Fig 1 and 2) Leaf folder The per cent leaffolder damage was found to be minimum in carbosulfan 6G (NS) at 1250 g a.i. ha -1 and at par with carbosulfan 6G (NS) at 1000 g a.i. ha -1, carbosulfan 6G (ES) at 1000 g a.i. ha -1 in both season field trials. The standard check phorate 10G 1000 g a.i. ha -1 caused only and per cent reduction in leaf damage in the first and second seasons respectively, where as reduction in test doses of carbosulfan 6G ranging from to and to per cent in first and second season respectively. The result of the present findings is in conformity with the observations made by Saroja and Raju (1982) who observed that carbosulfan 24 EC was more effective in checking the leaffolder at 15 DAT (7.1% leaf damage) as against 68.9 per cent leaf damage recorded in untreated control. Watanasit et al. (2000) found that under laboratory conditions, the entomopathogenic nematode, Steinernema carpocapsae Weiser when mixed with carbosulfan insecticide at 24 hours before applying them on larvae of leaffolder (Cnaephalocrocis medinalis) on filter paper were able to kill 80 per cent of C. medinalis larvae. Gowda and Naik (2005) reported that flubendiamide 20 WDG at 12.5, 25 and 50 g a.i. ha -1 was found ineffective in reducing the leaffolder damage.

181 Per Cent Damage Reduction Over Control Per Cent Damage Reduction Over Control Fig.1 Efficacy of Carbosulfan 6G (NS) on the per cent damage of stem borer and leaf folder in rice Season I T1 T2 T3 T4 T5 T6 Treatments Stem Borer Leaf Folder Fig.2 Efficacy of Carbosulfan 6G (NS) on the per cent damage of stem borer and leaf folder in rice Season II T1 T2 T3 T4 T5 T6 Treatments Stem Borer Leaf Folder Treatment Details: T 1 : Carbosulfan 6G 600 g a.i. ha -1 T 2 : Carbosulfan 6G 750 g a.i. ha -1 T 3 : Carbosulfan 6G 1000 g a.i. ha -1 T 4 : Carbosulfan 6G 1250 g a.i. ha -1 T 5 : Carbosulfan 6G 1000 g a.i. ha -1 T 6 : Phorate 1000 g a.i. ha -1

182 Per Cent Reduction Over Control Per Cent Reduction Over Control Fig.3 Efficacy of Carbosulfan 6G (NS) on the population of GLH, BPH and WBPH, in rice Season I T1 T2 T3 T4 T5 T6 Treatments GLH BPH WBPH Fig.4 Efficacy of Carbosulfan 6G (NS) on the population of GLH, BPH and WBPH, in rice Season II T1 T2 T3 T4 T5 T6 Treatments GLH BPH WBPH Treatment Details: T 1 : Carbosulfan 6G 600 g a.i. ha -1 T 2 : Carbosulfan 6G 750 g a.i. ha -1 T 3 : Carbosulfan 6G 1000 g a.i. ha -1 T 4 : Carbosulfan 6G 1250 g a.i. ha -1 T 5 : Carbosulfan 6G 1000 g a.i. ha -1 T 6 : Phorate 1000 g a.i. ha -1

183 The efficacy of flubendiamide at 24, 50 g a.i. ha -1 was found to be on par with carbosulfan 6G (NS) at 1000 g a.i. ha -1 (Thilagam, 2006). who reported that the combination products (fipronil +fenobucarb) at 1000 and 1250 ml ha -1 were effective in reducing the leaffolder incidence followed by triazophos at 750 ml ha -1 during both kharif and rabi seasons (Fig 1 and 2) Green leafhopper Carbosulfan 6G (NS) recorded a significant reduction in the GLH population and the effect was remarkable in both the seasons. Carbosulfan 6G (NS) at the test doses viz., 600, 750, 1000 and 1250 g a.i. ha -1 registered to and to per cent mean reduction in GLH population in season I and season II, respectively. Carbosulfan 6G (ES) at 1000 g a.i. ha -1 was effective in reducing GLH population than the untreated control. Several workers confirmed the effectiveness of carbosulfan against rice leafhoppers. Foliar application of carbosulfan g a.i ha -1 was found to be effective in controlling the green leaf hopper in rice (Asaf Ali and Chinniah, 1999). Reissig et al. (1986) reported that monocrotophos and carbosulfan treatments significantly reduced the density of Green leafhopper than the untreated check. Krishnaiah and Kalode (1986a) reported that root dip treatment of carbosulfan showed the best control against green leafhopper, N. virescens. Superiority of higher doses of carbosulfan 6G in these studies were in accordance with the findings of Jasmine (2002) who reported that the highest dose of carbosulfan 25 EC at 300 g a.i. ha -1 was superior to the lower dose of 200 g a.i. ha -1 in controlling the thrips on cotton (Fig 3 and 4) Brown planthopper (BPH) and White backed brown planthopper (WBPH) The BPH incidence was reduced to an extent of to and to per cent in first and second season, respectively in the test doses of carbosulfan 6G (NS). The highest dose of carbosulfan 6G (NS) at 1250 g a.i. ha -1 gave satisfactory control of N.lugens on rice.

184 Carbosulfan 6G (NS) at test doses 1250, 1000, 750 and 600g a.i. ha -1 recorded 71.34, 68.50, 62.42, per cent WBPH reduction in first season and 76.95, 68.73, 65.33, per cent reduction in second season, respectively. The efficacy was dose dependent. The results of present findings are in agreement with findings of Krishnaiah et. al., (1982) who reported that among the 14 spray insecticides, carbosulfan at 0.05% had good knock down effect of BPH and persisted for a longer period, exhibiting high contact toxicity when tested by Potters Tower method. Henrichs and Valencia (1981) found that carbosulfan (0.75 kg a.i. ha -1 ) as foliar spray had good ovicidal effect on BPH. Krishnaiah and Kalode (1986b) also reported that carbosulfan was the most effective in controlling WBPH with highest persistence among the tested insecticides. Brown planthopper N. lugens, white backed planthopper S. furcifera in rice were effectively controlled by granular insecticides viz., cartap hydrochloride 4G, chloropyriphos 15G, carbosulfan 5G, quinolphos 5G, carbofuram 3G and phorate 10G (Lal, 2000). Krishnaiah et al. (2008) also found that carbosulfan (0.02%) emulsion as seedling root dip is the best treatment against GLH, BPH and WBPH among the several insecticides tested. They also observed that carbosulfan had excellent translocation in the plant system moving through xylem from lower to upper portions of the plant and then disbursing into the phloem through other tissues, which alone can bring about excellent control of BPH and WBPH which are purely phloem feeders. High innate toxicity of carbosulfan to leaf and planthoppers might be considered as the reason for its effectiveness (Fig 3 and 4) Safety of carbosulfan 6G (NS) to natural enemies in rice Field experiments to evaluate the safety of carbosulfan 6G (NS) against natural enemies viz., spiders, mirids and rove beetle revealed that carbosulfan at lower doses were comparatively less toxic to the natural enemies than higher doses. The insecticides evaluated for toxicity against spiders in rice ecosystem showed that there was considerable decrease in spider population in all the treatments. Later it started increasing, but it was less than in untreated check.

185 The effect of insecticides on a particular natural enemy involves numerous biotic and abiotic factors. An extensive use of synthetic chemicals may result in the destruction of non target organisms directly or indirectly by entering into the niche of the organisms. Therefore, safety studies should be done to know the selectivity of the chemical (Nasreen et al., 2005). In the present study, the safety of carbosulfan 6G (NS) to spiders, mirid bugs and rove beetle of rice ecosystem was evaluated. The rice ecosystem normally includes beneficial predators and parasites in numbers that frequently provide partial or satisfactory pest control. Carbosulfan 6G (NS) at 1250 and 1000 g a.i. ha -1 recorded a mean spider population of 6.90, 6.92 and 6.02, 6.39numbers per five hills after the second application in season I and II respectively whereas untreated check recorded 8.37 and 6.44 numbers per five hills. Though there was sudden decline in the spider population on 7 DAT, the number started increasing gradually from 14 th day onwards and at 21 days after treatment even the highest dose recorded a population that was more or less equal to untreated check. The effect of carbosulfan 6G (NS) on mirid bugs revealed that there was minimum population at 7 DAT and increased gradually. Among the insecticidal treatments, the lowest mean mirid bug population of 5.37 and 5.47 per five hills in the first season and 4.63 and 4.77 per five hils in second season were recorded after the second application, in phorate 10G 1000 g a.i. ha -1 and carbosulfan 6G (NS) 1250 g a.i. kg -1, respectively, where as the untreated check recorded 6.15 and 5.54 numbers per five hills in first and second season, respectively. The influence of carbosulfan 6G (NS) on rove beetle revealed that there was minimum population at 7 DAT and increased gradually. Among the insecticidal treatments, the lowest mean mirid bug population of 6.26 and 6.38 per five hills in the first season and 6.29 and 6.34 per five hills in second season were recorded after the second application, in phorate 10G 1000 g a.i. ha -1 and carbosulfan 6G (NS) 1250 g a.i. kg -1, respectively, where as the untreated check recorded 7.13 and 6.65 numbers per five hills in first and second season, respectively. Results of the present study are similar to the earlier study of Raman and Uthamasamy (1983) who observed the least mortality of spider, Lycosa psuedoannulata

186 Yield (Kg/ha) Grain Yield (Kg/ha) Fig.5 Effect of Carbosulfan 6G (NS) on rice yield T1 T2 T3 T4 T5 T6 T7 Treatments Grain Yield (Kg/ha) I Season Grain Yield (Kg/ha) II Season Fig.6 Effect of Carbosulfan 6G (NS) on black gram yield T1 T2 T3 T4 T5 T6 T7 Treatments Grain Yield (Kg/ha) I Season Grain Yield (Kg/ha) II Season Treatment Details: T 1 : Carbosulfan 6G 600 g a.i. ha -1 T 2 : Carbosulfan 6G 750 g a.i. ha -1 T 3 : Carbosulfan 6G 1000 g a.i. ha -1 T 4 : Carbosulfan 6G 1250 g a.i. ha -1 T 5 : Carbosulfan 6G 1000 g a.i. ha -1 T 6 : Phorate 1000 g a.i. ha -1 T 7: Untreated control