SPATIAL DISTRIBUTION OF ANOPHELINE SPECIES IN MEGHALAYA HIGHLANDS: EFFECT OF LAND USE AND TOPOGRAPHY

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1 SPATIAL DISTRIBUTION OF ANOPHELINE SPECIES IN MEGHALAYA HIGHLANDS: EFFECT OF LAND USE AND TOPOGRAPHY THESIS ABSTRACT SUBMITTED IN FULFILLMENT OF THE REQUIREMENTS OF THE DEGREE OF DOCTOR OF PHILOSOPHY IN ZOOLOGY BY ATIN KUMAR SRIVASTAVA DEPARTMENT OF ZOOLOGY NORTH-EASTERN HILL UNIVERSITY SHILLONG , INDIA 2013

2 SPATIAL DISTRIBUTION OF ANOPHELINE SPECIES IN MEGHALAYA HIGHLANDS: EFFECT OF LAND USE AND TOPOGRAPHY THESIS ABSTRACT SUBMITTED IN FULFILLMENT OF THE REQUIREMENTS OF THE DEGREE OF THE DOCTOR OF PHILOSOPHY IN ZOOLOGY BY ATIN KUMAR SRIVASTAVA DEPARTMENT OF ZOOLOGY NORTH EASTERN HILL UNIVERSITY SHILLONG , INDIA 2013

3 Anopheles (Family: Culicidae) is one of the best-known groups of Order: Diptera, due to their importance in transmission of disease such as malaria. The genus Anopheles consists of about 469 formally named and more than 50 unnamed species. Out of these, 70 species have capacity to transmit human malaria parasite and 41 are considered dominant vector species. Anopheles mosquitoes have been more closely studied in India then in other country. Anopheles has been reported to be found from each and every part of India wherever careful search for them has been made. They have been reported, even from the places situated at height 3,530 meters above the sea level or at the 92 meter depth of coal- mine of Bihar. Now, 58 species of Anopheline are known in India, of which six are primary vectors namely Anopheles culicifacies, An. dirus, An. fluviatilis, An. minimus, An. sundaicus and An. stephensi and their distribution strictly follows the physiography, climate and hydrology. Anophelines are well known as only potential vector of human malaria but their importance in the transmission of certain other diseases has also been recognized. Their involvement in different diseases such as Japanese encephalitis, bancroftian filariasis, Malayan filariasis, Filariasis, Ross River virus, Cache Valley virus and O Nyong nyong virus etc has also been suggested. These diseases are wide spread in tropical and sub-tropical regions of the world and impose great socio-economic burden on humanity with six other diseases like HIV/AIDS, tuberculosis, leprosy, measles, hepatitis B and pneumonia. All these diseases including malaria cover around 85% of global infectious disease burden. Of these diseases, malaria is one of the most important killers of humans worldwide, threatening the lives of more than one-third of the world s population. World Health Organization (WHO) in 2010 estimated that there are 106 countries in the world where 1 P a g e

4 malaria is endemic and India is one of them. About 36% of the world population (i.e., 2020 million) living in these countries are at risk, with fatal rates being extremely high among young children below 5 year of age. As per WHO report in 2010 concerning South-east Asian region, out of 1.4 billion people living in 11 countries of South-east Asia, 1.2 billion (about 87%) are exposed to the risk of malaria and most of them live in India. The disease primarily affects poor population in tropical and subtropical areas, where the temperature and rainfall are suitable for the development of vectors and parasites. Within South-east Asian countries, India is one of the most dangerous foci of malaria which has contributed about 76% of the total reported cases in Southeast Asia during There are total 28 States and 7 Union territories in India in which Rajasthan, Gujarat, Karnataka, Goa, southern Madhya Pradesh, Chhattisgarh, Jharkhand Orissa, and also the North-eastern States are malaria endemic where annual parasite incidence (API) is more than 5. Meghalaya is an important North-eastern State of India famous for the place of highest rainfall in the world. Its geographical territory lies between latitude N to N and longitudes E to E. At present the State has eleven administrative districts. The study was started in 2008 and at that time there were only seven districts i.e. East Khasi Hills, West Khasi Hills, Jaintia Hills, Ri-Bhoi, East Garo Hills, West Garo Hills and South Garo Hills and in the description of the study, same nomenclature of seven districts is being used. These districts are predominantly inhabited by three major ethnic groups e.g. the Khasis, the Jaintias and the Garos. These tribal communities are the descendents of very ancient people having distinctive traits and ethnic origins. 2 P a g e

5 In Meghalaya, incidence of malaria has been reported to increase significantly from the year The annual average prevalence of malaria in India is 106 per 100,000 population, whereas in Meghalaya it is 920 per 100,000 population, which is about 8.6 times more than the national average. The prevalence rate of malaria in Meghalaya is highest in the North-eastern States and second in India. Climatic condition of low land areas of the State is warm and humid, but highland areas are cold. The occurrence of malaria has been reported to be prevalent in foothills and valleys of Meghalaya, but now it has been noted to gradually spread in the highland areas also. The main cause for this rise in infection is may be land use and human settlement pattern. Land use and land cover (LULC) are two related biophysical characteristics of the earth where land cover refers to the cover of earth surface and land use is the way in which human exploit the land cover. A land cover change occurs in the form of urbanization, deforestation, industrialization, reforestation, water control systems and agricultural development. The driving force to this activity could be economic, technological, demographic, scenic, and or other factors. These modified land sizes are expanding at the expense of natural vegetation. This type of land use divides big land area into small land patches and alters elements of local ecosystem such as soil character, ph, ecology of local flora and fauna and most important surrounding area temperatures patches are situated in the same locality, each has a different environmental character. In each patch, several types of resources are available to Anopheline mosquitoes. 3 P a g e

6 The understand and establish the effect of land use and land cover modification on Anopheles mosquitoes distribution and abundance in different districts of Meghalaya, the present study has been undertaken with following objectives: 1) General survey of Anopheles mosquitoes in Meghalaya 2) Understand population dynamics, breeding biology, and distribution status of mosquito species 3) Generate baseline data about mosquito bionomic in different land use 4) To examine the effect of land use/ land cover types on distribution of Anopheles in Meghalaya highlands The findings from the present study may help a lot in constructing new work strategy and target specific action plans to control mosquito borne diseases. In this survey, effects of LULC changes on the distribution of Anopheline species abundance and density in Meghalaya over a four-year period (February 2008 to March 2012) was observed. For study, land use in Meghalaya was initially classified into two broad categories, natural (essentially consisting areas with typical natural vegetation (NFA) covers, with little or no human interference) and artificial. The artificial land use type was further subdivided into following categories: Farm land area (FLA); Urban land area (ULA); Pasture land area (PLA); and converted or Open forest area (OFA). Five sites were selected from each district and each site representing a land use category (NFA, FLA, ULA, PLA and OFA). The LULC change detection was achieved by using prepared LULC maps , procured from ISRO s new web portal Bhuvan. The maps were re-projected using Erdas Imagine 9.1 software to give map properties to the images. The verification of these land use types was done through field surveys in both the rainy as well as dry seasons 4 P a g e

7 for three years , using handheld global positioning system (GPS) devices. In order to calculate the area of each class of LULC map, the calculated geometry function in attribute table of ArcGIS 9.2 software was used. The changes in LULC of each class were obtained by comparing the area in 2008 with that in 2012; these changes were presented graphically. Environmental variables recorded for each habitat were: size, water temperature, ph, dissolved oxygen, water surface area, water turbidity, distance from colony, canopy cover, aquatic animals and substrate type. Substrate type was classified as muddy, sandy with gravel and soil, and artificial without soil. Water ph, temperature, conductivity, dissolved oxygen, turbidity, and light intensity of larval habitat were recorded by means of a portable meter. Mosquitoes density and diversity of neighbouring seven villages located along natural swamps (less disturbed) were also compared with twenty eight villages located near disturbed area (cultivated area, urban area, pastures land are open forest area). The association between LULC type and occurrence of Anopheline larvae was statistically significant. The distribution of anopheline positive habitats varied significantly between seasons. The mean density of Anopheles was significantly higher in urban area in all the seasons, but higher in farm land and pasture land areas only in rainy and post-rainy seasons. The six most common species collected were Anopheles maculatus (21.7%), An. vagus (15.2%), An. annularis (12.9%), An. philippinensis (9.8%), An. nigerimus (9.8%) and An. minimus (8.7%). Comparison of 2012 LULC assessment with the previous 2008 assessment shows LULC changes significantly at State level as well as districts level also. There was general increase in OFA sq. km (4%) which is evident in the reduction in the NFA and PLA. The 5 P a g e

8 analysis also revealed that 8.2% sparsely cultivated land in 2008 were converted in intensively cultivated land and 3.6% shifting cultivated land were converted in moderately cultivated land. On the basis of various findings from the present study, it may be concluded that Meghalaya highlands are heavily forested, providing an environment unfavorable to Anopheles mosquitoes. Clearance of the forest for agricultural activity or urbanization provided further suitable mosquitoes breeding sites. Thus, deforestation may be one of the main reasons for increased mosquitoes in Meghalaya. These types of land use practices mainly affect the growing conditions of anopheline larvae and habitat availability. The results of this survey also support the hypothesis that recent LULC changes in Meghalaya provide suitable habitat conditions for Anopheles mosquitoes. Deforestation and unplanned urbanization creates suitable habitats for Anopheles. These findings also improve the understanding of LULC effects on anopheline ecology and may be useful in formulating new and effective malaria control programmers in Meghalaya. Extended studies were also carried with the idea to identify and document all traditionally antimalarial plants that is used by the ethnic groups i.e. Garos, Khassi and Jaintias of the Meghalaya State and to provide comprehensive details to back up their antimalarial potential based on the information obtained during the survey such as frequency of usage, number of times the plant was mentioned, and previous literature on said plant. The result of the study shows that traditional medicine is still playing a significant role in health care need of indigenous people of Meghalaya. Around 60% of total population and 80% of rural population are depending on the traditional 6 P a g e

9 antimalarial medicines. Main cause of dependency on traditional medicine could be the availability of treatment in health services at high cost and lack of poor services or lack of affordability in rural areas, Total 27 plant species were identified in which 18 are well known antimalarials Thus, It may be concluded that ethnic people of Meghalaya have specialized indigenous knowledge about antiplsomodial as well as antimosquito plants. As the people of these community inherit a rich traditional knowledge and documentation of this knowledge has provided novel information from the area. This will not only provide recognition of this undocumented knowledge but this information can also assist identify which species should be given priority. This study may also be providing ethical support to their folklore knowledge of medicinal plants. 7 P a g e