Project Title: Development and Implementation of Novel Trapping Systems for Monitoring Cranberry Fruitworm and Cranberry Weevil Populations

Transcription

1 Program: RIPM Project Title: Development and Implementation of Novel Trapping Systems for Monitoring Cranberry Fruitworm and Cranberry Weevil Populations Project Director Cesar Rodriguez-Saona, Rutgers University Co-PDs Rufus Isaacs, Michigan State University Stelinski Lukasz, University of Florida Anne Averill, University of Massachusetts Start Date: Jun End Date: Jun Extension Funding: $ 15,000 Research Funding: $ 115,000 Total Funding: $ 130,000 Summary This project was conducted in New Jersey, Michigan, and Massachusetts on two native North American specialty crops: blueberries and cranberries. These are two of the most economically important domesticated and commercially-produced Vaccinium spp. (Ericaceae) in North America. Massachusetts and New Jersey, account for more than 40% of the total US cranberry acreage and for more than 30% of the total US production, valued at $65.3 million. Most blueberries are grown in Michigan and New Jersey. These two states account for approximately 50% of the total US blueberry acreage and for more than 45% of the total utilized production, valued at $139 million. The two insect pests in this study, the cranberry fruitworm and cranberry weevil can cause major economic losses in blueberries and cranberries in the northeastern US. These insects feed on the plant's reproductive organs (flower buds, flowers, and fruit), which makes them major direct pests in the growing areas where they occur; thus, even few individuals may cause a substantial loss to growers. Current monitoring techniques for cranberry weevil and cranberry fruitworm populations are very limited, which restrict the scope of current management practices. The purpose of this study was to provide cranberry and blueberry growers with new tools for monitoring cranberry weevil and cranberry fruitworm populations that can be implemented into reduced-risk IPM programs. An important breakthrough from this project was the first identification of the cranberry weevil aggregation pheromone. The cranberry weevil pheromone was identified as a mixture of Grandlure II, Grandlure III, Grandlure IV, and geraniol at approximately 2.3, 0.73, 0.5, and 0.07 ng/adult/day, respectively. Field experiments showed that adult cranberry weevils are attracted to the pheromone blend in commercial blueberry and cranberry farms. This work contributed towards our ongoing efforts to implement better monitoring techniques and new reduced-risk strategies into pest management programs in cranberries and blueberries. This project identified a lure that can be used to monitor adult cranberry weevil populations in blueberry and cranberry IPM programs.

2 Problem, Background, and Justification Highbush blueberries (Vaccinium corymbosum) and cranberries (Vaccinium macrocarpon) are both native to North America, and have been under commercial cultivation for many years. Blueberries and cranberries are two of the most important crops in the northeast US: highbush blueberries are grown on 60,180 acres, mainly in Michigan (18,600 acres), Georgia (9,500 acres), and New Jersey (7,600 acres), while cranberries are grown in over 39,000 acres, primarily in Wisconsin (17,700 acres), Massachusetts (13,000 acres), and New Jersey (3,100 acres). Michigan and New Jersey, two of the states involved in this proposal, account for approximately 50% of the total US blueberry acreage and for more than 45% of the total utilized production, valued at $139 million. Massachusetts and New Jersey, account for more than 40% of the total US cranberry acreage and for more than 30% of the total US production, valued at $65.3 million. The two insect pests in this study, cranberry weevil, Anthonomus musculus, and the cranberry fruitworm, Acrobasis vaccinii, can cause major economic losses in the northeast US. Both insects feed on the plant s reproductive organs (flower buds, flowers, and fruit), which makes them major direct pests in blueberries and cranberries in the growing areas where they occur. In New Jersey blueberries, cranberry weevil adults are monitored using beating trays. In cranberries, weevil adults are monitored using sweeping. These monitoring methods are labor-intensive. No pheromone has been identified for cranberry weevil. In blueberries, monitoring techniques for cranberry fruitworm involve the use of sex-pheromone baited traps for capturing male moths, combined with berry inspections. In cranberries, IPM programs do not rely on monitoring for determining the timing of the initial sprays and instead, recommend two prophylactic sprays based upon crop phenology; these are followed by collection and visual examination of fruit for presence of visible eggs. Berry inspection is laborintensive. A cost-effective and reliable method for monitoring cranberry weevil and cranberry fruitworm adults is critical to accurately time insecticide applications. This study s ultimate goal was to provide cranberry and blueberry growers with new tools for monitoring populations of these two major pests. This project investigated a low-cost, easy-to-use, and reliable monitoring technique based on combinations of insect pheromones and host-plant attractants to eliminate or precisely time insecticide applications. The present project addressed a top research priority stated by the Fruit IPM Working Group, which is to develop and implement Effective monitoring strategies for key pests in which technologies currently do not exist By better monitoring and timing applications of insecticides to control cranberry weevil and cranberry fruitworm, we expect a reduction in insecticide use in cranberry and blueberry fields. This reduction of insecticide use coupled with an increase in use of selective reduced-risk practices will have a positive impact on the environment. Furthermore, use of traps will reduce the need for scout visits that are costly and laborintensive, and minimize exposure of scouts to pesticide residues. Objectives The ultimate goal of this project was to provide cranberry and blueberry growers with new tools for monitoring cranberry fruitworm and cranberry weevil populations.

3 The following were specific objectives: 1) Assess the behavioral responses of adult cranberry fruitworm and cranberry weevil to host-plant volatiles; 2) Identify volatiles important in attraction of the cranberry fruitworm and cranberry weevil to plants; 3) Evaluate potential compounds and techniques to attract and trap adults in the field; 4) Implement traps into a reduced-risk IPM program; 5) Distribute information on monitoring and control of cranberry fruitworm and cranberry weevil populations to growers. Approach and Procedures Populations of cranberry weevil and cranberry fruitworm from Michigan, Massachusetts, and New Jersey were tested for their behavioral and electro-antennogram (EAG) responses to blueberry and cranberry volatiles. The behavioral responses of these insects were studied using olfactometers. Y-tube olfactometer assays were conducted to assess the attractiveness of cranberry weevil to damaged and undamaged buds and flowers. Volatiles from blueberry buds and open flowers were collected and identified using headspace volatile collections, gas chromatography (GC), and GC-mass spectrometry (GC-MS) (Appendix A). Results from these studies were published in Szendrei, Z., Malo, E. Stelinski, L., and Rodriguez-Saona, C Response of cranberry weevil (Anthonomus musculus Say, Coleoptera: Curculionidae) to host plant volatiles. Environ. Entomol. 38: (Appendix B). In the field, traps baited with cinnamyl alcohol, the major volatile component of blueberry flowers, and pepper weevil pheromone were investigated for cranberry weevil attraction. Two types of traps were compared: soil traps (placed at ground level) and yellow sticky traps (placed at canopy level). Cinnamyl alcohol was formulated in two different types of lures: Bubbles (manufactured by AgBio Inc.) and SPLAT (manufactured by ISCA Technologies). Cranberry weevil attraction to the commercially available pepper weevil sex-pheromone lure was also tested. Traps were placed at four commercial highbush blueberry farms located in the main blueberry growing regions of New Jersey, along the field edge near wooded borders. Traps were monitored weekly for cranberry weevils starting in early April and ending in July To identify the cranberry weevil pheromone, headspace volatiles were collected from adults feeding on blueberry buds and analyzed via GC-MS. In 2009, field experiments were conducted in four blueberry farms in New Jersey and four cranberry farms in Massachusetts to test the attraction of cranberry weevil to traps baited with the cranberry weevil pheromone alone and combined with the host-plant volatiles (Z)-3- hexenyl acetate and hexyl acetate. The cranberry weevil pheromone was also compared with the pepper weevil and boll weevil lures. A total of ten treatment lures, including a non-lure control, were tested in a randomized complete block design with four replicates at each of the eight farms. In 2010, the cranberry weevil pheromone was used in combination with reduced-risk insecticides to monitor and control this pest. Experiments were also conducted to test the attraction of cranberry fruitworm to blueberry volatiles and synergistic effects of host-plant volatiles with its sex pheromone. These experiments were conducted in eight commercial blueberry farms: four in New

4 Jersey and four in Michigan. In 2008, we tested 29 blueberry volatile lures in a randomized complete block design with one replicate per farm: 26 single-component leaf and flower lures, 1 leaf blend, 1 flower blend, and 1 non-lure control. Each lure was tested at 30 and 100 mg. In 2009, ten treatment lures were compared at two different doses (1 and 5 g): 1 green leaf volatile (GLV) blend ((Z)-3-hexenyl acetate, hexyl acetate, (Z)-3-hexen-1-ol, and hexanol), 1 GLV blend + CBFW sex pheromone, 1 GLV + linalool, 1 GLV + linalool + pheromone, 1 phenylacetaldehyde (PAA), 1 PAA + pheromone, 1 PAA blend, 1 PAA blend + pheromone, 1 sex pheromone, and 1 control. Several methods were used to transfer the data from this study to growers: the results from this study were presented at New Jersey, Michigan, and Massachusetts grower meetings, the information was transferred to IPM coordinators in each state, Fact sheets (please see Appendix C and D) and newsletters were written on cranberry weevil and cranberry fruitworm biology and control. Scientific articles were written on the development and efficacy of traps (please see Appendix B and E). Information was transferred to major pheromone suppliers (ISCA Technologies and AgBio, Inc.). Progress In 2009, we identified the main components of the cranberry weevil aggregation pheromone. Headspace volatiles collected from adult male and female cranberry weevil feeding on flowering blueberry and cranberry plants were analyzed by gaschromatography (GC) and mass spectrometry (GC-MS). Male specific compounds were identified as a mixture of Grandlure II (Z isomer), Grandlure III, and Grandlure IV (Fig. 1A). In addition, geraniol was released by males and females (Fig. 1B). The emissions of these compounds were approximately 2.3, 0.73, 0.5 and 0.07 ng/male/day, respectively (cranberry weevil pheromone blend). Fig 1. A. Male Grandlure II Grandlure III Grandlure IV B. Female Geraniol retention time (min) Fig 1. Cranberry weevil pheromone. Male-producing compounds (A). Female-producing compounds (B)

5 Weevils per trap (Mean SEM) The cranberry weevil pheromone was tested in 2009 field experiments. These experiments were conducted using yellow sticky traps baited with the male pheromone blend (grandlure blend) alone or combined with geraniol (CBW pheromone full blend) at four commercial cranberry farms in Massachusetts and four blueberry farms in New Jersey. Lures with specific cranberry weevil pheromone blends were compared to commercially available pepper and boll weevil lures. The experiment was a randomized complete block design, with four replications at each of the eight farms. In both states and crops, the lure that contained the grandlure blend supplemented with geraniol (CBW pheromone full blend) attracted the highest number of adults (Fig. 2). More weevils were caught on traps from the summer generation, perhaps indicating a stronger response to the pheromone. Fig Blueberry Overwintered, NJ 16 Blueberry Summer generation, NJ 16 Cranberry Summer generation, MA a ab ab 8 8 a 8 4 c c a a c abc 4 d d b d c 4 b b b 0 Fig 2. Results from our 2009 field experiment. Different letters above bars and within graphs indicate significant differences, (Tukey test: P 0.05) among treatments Further analyses of the headspace emissions of adult cranberry weevil done in 2009 indicated that there are two previously undetected minor compounds (an acid similar to nerolic/geranic acid and an alcohol similar to nerol/geraniol; Fig. 3) released by males, which might have behavioral significance. However, we have yet to determine their biological activity. Future studies need to optimize the trap and lure by investigating different trap colors, designs, placement, formulations, and refined pheromone blends to determine the most attractive combination to cranberry weevil.

6 Abundance (x1000) Fig New-ol New-acid 160 Grandlure II Grandlure III Grandlure IV 40 Geraniol retention time (min) Fig 3. Minor cranberry weevil pheromone components found in 2009 In 2010, experiments were conducted to evaluate the cranberry weevil pheromone combined with reduced-risk insecticides. These experiments tested the efficacy of Asana (grower standard), Assail, Avaunt, and Mustang Max against cranberry weevil in blueberries in New Jersey. The experiments were conducted in four fields at three commercial farms. Pheromone-baited traps were used to time insecticide sprays. In addition, samples were taken using a standard beating sheet. Insecticide applications were done when populations reached a threshold of ~5 weevils per bush. Data on cranberry weevil counts per bush were analyzed using ANOVA followed by Fisher s LSD test. Results showed that the reduced-risk insecticide Avaunt was as effective as the grower standard Asana in reducing weevil populations. These results indicate that an effective trapping system for cranberry weevil may be used with the reduced-risk insecticide Avaunt in blueberry and cranberry IPM programs. Treatment Rate No. Weevils per Bush (Mean±SE) 1 Pre-Spray 6 April Assail 30SG 5.3 oz/ac 4.5 ± 1.6 a 2.2 ± 1.0 a 52.4 Asana XL 9.6 floz/ac 5.3 ± 1.2 a 0.0 ± 0.0 b Avaunt 30WDG 6.0 oz/ac 5.3 ± 1.1 a 0.0 ± 0.0 b 99.4 Mustang Max EC 4.0 floz/ac 5.5 ± 1.2 a 0.3 ± 0.2 b Means within a column followed by different letters are significantly different 2 %Control = (1- (No. CBW Postspray / No. CBW Prespray)) x 100 Post-Spray April % Control 2

7 Outcomes This project identified the first lure that can be used to monitor adult cranberry weevil populations in blueberry and cranberry IPM programs. In the laboratory, Y-tube olfactometer assays showed that female cranberry weevil are attracted to blueberry flowers, while males are attracted to undamaged flower buds and are repelled by damaged flower buds. Nineteen volatiles were identified from blueberry buds, nine of these were also emitted from blueberry flowers including the green leaf volatiles (GLV) (Z)-3-hexenyl acetate and hexyl acetate. Cinnamyl alcohol was the major component of blueberry flowers. A field experiment conducted in 2008 showed that yellow sticky traps baited with cinnamyl alcohol capture similar cranberry weevil adults as compared with unbaited traps. In the same study, cranberry weevil attraction to the commercial pepper weevil aggregation pheromone was tested and found to be highly attractive. To identify the cranberry weevil pheromone, headspace volatiles were collected from adults feeding on blueberry buds and analyzed via GC-MS. The cranberry weevil aggregation pheromone was identified as a mixture of Grandlure II, Grandlure III, Grandule IV, and geraniol at approximately 2.3, 0.73, 0.5, and 0.07 ng/adult/day, respectively (cranberry weevil pheromone lure). In 2009, field experiments were conducted in four blueberry farms in New Jersey and four cranberry farms in Massachusetts to test the attraction of cranberry weevil to traps baited with the cranberry weevil pheromone alone and combined with (Z)-3-hexenyl acetate and hexyl acetate. The cranberry weevil pheromone was also compared with the pepper weevil and boll weevil lures. The cranberry weevil pheromone lure attracted the highest number of adults. Addition of the GLV skewed the sex ratio of the captured weevils towards females. Experiments were also conducted to test the attraction of cranberry fruitworm to blueberry volatiles and synergistic effects of GLV with its sex pheromone. None of the host-plant volatiles tested attracted adults cranberry fruitworm or affected the response to its sex pheromone. Several venues were used to disseminate the results from this project to our various stakeholders, i.e., scientific community, blueberry and cranberry growers, students, general public, research and extension specialists, county agricultural agents, and private industry. These included presentations at several scientific meetings and invited seminars. Work from this project was presented by Dr. Zsofia Szendrei (Rutgers research associate hired to work on this project) at the 2008 XXIII International Congress of Entomology (Durban, South Africa), 2008 Annual Entomological Society of America (Reno, NV), 2008 International Society of Chemical Ecology Annual Meeting (State College, PA), 2009 North American Cranberry Research and Extension Workshop (New Brunswick, Canada), and 2009 Entomological Society of America Annual Meeting (Indianapolis, Indiana). Dr. Rodriguez-Saona (project PI) also gave invited seminars on the project s findings at Michigan State University (Fall 2009), Simon Fraser University (Spring 2010), Pennsylvania State University (Spring 2010), and Rutgers University (Spring 2010). This work was also presented at growers meetings. Dr. Szendrei presented her results at the 2009 Vegetable and Fruit Conference (Atlantic City, NJ). Dr. Rufus Isaacs (project co-pi, Michigan State University) was invited by Dr. Rodriguez-Saona to present current work on cranberry fruitworm to blueberry growers at the 2009 Vegetable and Fruit Conference (Atlantic City, NJ). Dr. Anne Averill (project co-pi, University of

8 Massachusetts) was invited by Dr. Rodriguez-Saona to present current research on cranberry fruitworm to cranberry growers at the American Cranberry Growers Association (Bordentown, NJ). Two extension factsheets were produced during the course of this project: one on cranberry weevil biology and management (The cranberry weevil in blueberries. Rutgers NJAES Cooperative Extension FS1087) and one on cranberry fruitworm biology and management (Cranberry Fruitworm: A Pest of Blueberries in New Jersey. Rutgers NJAES Cooperative Extension FS1114). Copies of these factsheets were given to growers at the 2010 Blueberry Open House (Hammonton, NJ). A project website was created to inform the public about the project s goals and outcomes ( Information on cranberry weevil and cranberry fruitworm biology and control recommendations was also available via the Rutgers Blueberry Bulletin, Plant & Pest Advisory Newsletters, Michigan Blueberry Newsletters, and UMass Cranberry Station Newsletters. During the course of this project, we partnered with two commercial companies for the development of lures: AgBio Inc. (Westminster, CO) and ISCA Technologies (Riverside, CA). Impacts We identified the first lure that can be used to monitor adult cranberry weevil populations. This lure can be implemented with reduced-risk insecticides in blueberry and cranberry IPM programs. Our findings addressed one of the top research priorities - stated by the Fruit IPM Working Group - to develop and implement Effective monitoring strategies for key pests in which technologies currently do not exist. By monitoring and better timing of insecticide applications to control cranberry weevil, as well as the cranberry fruitworm, we expect a reduction in overall pesticide use in cranberry and blueberry fields. Furthermore, an effective monitoring tool for cranberry weevil and cranberry fruitworm will reduce the need for costly and labor-intensive scouting. In 2010, we evaluated the cranberry weevil lure in several blueberry farms to evaluate its efficacy at large-scale blueberry fields in combination with reduced-risk insecticides. We are currently working with two companies in the development, evaluation, and future commercialization of this lure. However, before this is achieved the cranberry weevil pheromone needs to be optimized by testing different trap colors, designs, placement, formulations, and refined pheromone blends. We will seek future funding to conduct research on the optimization of the cranberry weevil pheromone. In the long-term, there are several environmental, health, and economic benefits that are anticipated from this and future studies. By monitoring and better timing of insecticide applications to control cranberry weevil and cranberry fruitworm, we expect a reduction in overall pesticide use in cranberry and blueberry fields. This reduction coupled with an increase in use of selective reduced-risk pesticides and alternative management practices will have a positive impact on the consumers health and the environment. Furthermore, the effective monitoring tools will reduce the need for costly and labor-intensive scouting and thus minimize exposure of scouts to pesticide residues.

9 List of Publications Szendrei, Z., Malo, E. Stelinski, L., and Rodriguez-Saona, C Response of cranberry weevil (Anthonomus musculus Say, Coleoptera: Curculionidae) to host plant volatiles. Environ. Entomol. 38: (Appendix B) Szendrei, Z., and C. Rodriguez-Saona Cranberry Weevil in Blueberries. Fact Sheet FS1087. Rutgers Cooperative Extension. (Appendix C) Szendrei, Z., and C. Rodriguez-Saona Cranberry Fruitworm: A Pest of Blueberries in New Jersey. Fact Sheet FS1114. Rutgers Cooperative Extension. (Appendix D) Szendrei, Z., and Rodriguez-Saona, C A meta-analysis of behavioral manipulation of insect pests with plant volatiles. Entomol. Exp. et Appl. 134: (Appendix E) Szendrei Z Developing a cranberry weevil monitoring strategy for highbush blueberries. Proceedings of the 54rd New Jersey Annual Vegetable Growers Meeting. Atlantic City, NJ. List of Presentations Rodriguez-Saona, C The ecological roles of plant volatiles and their implications in insect pest management. Entomology Department. Rutgers University. New Brunswick, New Jersey. Rodriguez-Saona, C Integrating applied insect chemical ecology into blueberry pest management. Department of Entomology. Penn State University. State College, Pennsylvania. Rodriguez-Saona, C The ecological functions and applications in pest management of herbivore-induced plant volatiles. Department of Biological Sciences. Simon Fraser University. Vancouver, Canada. Rodriguez-Saona, C The scent of plants in insect-plant interactions and pest management. Department of Entomology. Michigan State University. East Lansing, Michigan. Szendrei, Z., H. Alborn, and C. Rodriguez-Saona Using semiochemicals for cranberry weevil (Anthonomus musculus Say) management. Entomological Society of America Annual Meeting. Indianapolis, Indiana. Szendrei, Z., H. Alborn, A. Averill, and C. Rodriguez-Saona Identification and field activity of the cranberry weevil pheromone. North American Cranberry Research and Extension Workers Conference. New Brunswick, Canada. Szendrei, Z., E. Malo, and C. Rodriguez-Saona Identification of volatile attractants for the cranberry weevil, Anthonomus musculus Say (Coleoptera: Curculionidae). Entomological Society of America Annual Meeting. Reno, Nevada.

10 Szendrei, Z., E. Malo, and C. Rodriguez-Saona Identification of host-plant attractants for the cranberry weevil, Anthonomus musculus Say (Coleoptera: Curculionidae). International Society of Chemical Ecology. 25th ISCE meeting, State College, Pennsylvania. Szendrei, Z., E. Malo, and C. Rodriguez-Saona Identification of host-plant attractants for the cranberry weevil, Anthonomus musculus Say (Coleoptera: Curculionidae). XXIII International Congress of Entomology. Durban, South Africa.