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Update on Duet ™ and insecticide-treated surfaces Sandra A. Allan Center for Medical, Agricultural and Veterinary Entomology ARS/ USDA Gainesville FL DoD Pest Management Workshop Jacksonville NAS February 12 2010. Update
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Update on Duet™ and insecticide-treated surfaces Sandra A. Allan Center for Medical, Agricultural and Veterinary Entomology ARS/ USDA Gainesville FL DoD Pest Management Workshop Jacksonville NAS February 12 2010
Update 1. Effect of ULV droplets of DUET™ on mosquito (Culex quinquefasciatus) responses 2. Behavioral effects of ULV droplets of DUET™ on the sand fly (Lutzomyia shannoni) 3. Effect of different insecticides on surfaces on landing by mosquitoes and sand flies
1. Effect of ULV droplets of DUET™ on Culex quinquefasciatus responses Duet™ New product Hypothesis Prallethrin contained in Duet enhances flight activity and results in greater mortality Objective Quantify mosquito excitation and mortality caused by Duet and its components applied as an ultra-low-volume aerosol Military Relevance Duet may be a ULV formulation useful for military applications
Formulations obtained from Clarke Mosquito Control Sprays delivered at a sublethal rate so that behavior can be observed sublethal
Video recording • Individual mosquitoes placed in screened cage in wind tunnel downwind of spray inlet Video recordings were 12.5 min long: pre-spray spray post-spray 5 min 2.5 min 5 min Laminizer Laminizer 4 ft Reducer Pesticide filters Filters Door Door Filters Fan air flow Fan * * Output o screened cage with mosquito Intake Side view of wind tunnel Pesticide cloud delivery
Video Analysis using behavioral analysis software (Observer) Behaviors of individual insects are coded with start and stop times by different keys and data exported to Excel for analysis Event time Behavior Assay cage in wind tunnel Event panel
Video Analysis using motion analysis software (Motus) Manual tracking of individual insect produces a flight track and x-and y-coordinates that are exported to Excel for further analysis Resulting flight track Assay cage in wind tunnel Cursor on top of insect
ULV Droplet analysis • Mosquitoes treated in the wind tunnel were dissected and body parts placed on slides • Droplets were measured and counted 50 microns
Conclusions Behavior: (pre-spray compared with spray and post-spray) • Prallethrin produced increasedflight activity (excitation) during spray • Sumithrin produced increased flight activity post-spray • Controls: no differences in behavior were observed Mortality: Increased mortality appears to be linked to increased activity levels during spray, especially when exposed to treatments with prallethrin
Droplets Pre-spray Spray Post-spray Increased flight results in increased droplet contact
2. Behavioral effects of ULV droplets of DUET™ on the sand fly (Lutzomyia shannoni) Objective Quantify sand fly excitation and mortality caused by Duet™ and its components applied as an ULV spray Methods Similar to study with mosquitoes except: • Used field-collected Lutzomyia shannoni • Smaller assay cages • Double screening to contain sand flies
Detection of ULV droplets of Duet on body parts 50 microns Sand fly wing Droplets most detected on wings of sand flies
Droplet size distribution – Comparison between sand flies and mosquitoes 10 microns Sand fly wing More small droplets detected on sand flies than on mosquitoes
Mortality of sand flies after treatment with Duet formulations in wind tunnel Treatments containing prallethrin Treatments containing prallethrin had higher mortality at 24 hr
Flight tracks of sand flies (Lutzomyia shannoni) exposed to ULV spray of Duet in wind tunnel During spray Sumithrin, PBO + inerts Prallethrin + inerts Prallethrin, PBO + inerts Duet (sumithrin, prallethrin, PBO + inerts) More movement by sand flies exposed to prallethrin Control (inerts)
Conclusions • Similar to mosquitoes, sand fly activity and mortality is enhanced in the presence of prallethrin
3. Effect of different insecticides on surfaces on landing by mosquitoes and sand flies If given a choice, will mosquitoes land on surfaces treated with residual pesticides? Are there differences between mosquitoes and sand flies? Objective To compare landing of mosquitoes and sand flies on surfaces treated with different residual pesticides Military Relevance To identify the most effective available residual pesticides for control of mosquitoes and sand flies
Methods Selected residual insecticides approved for application on vegetation and other surfaces for mosquito control Applied to surfaces at maximum label rate Active ingredient Formulation AI (%) Bifenthrin Talstar One 7.9 Cyfluthrin Tempo Ultra (SC) 11.8 Deltamethrin Suspend SC 4.75 Permethrin Dragnet 36.8 Lambda-cyhalothrin Triazicide 0.002%
Methods Species Aedes albopictus (lab-reared) Lutzomyia shannoni (field-collected) Phlebotomus papatasi (lab-reared) Approach Each test cage with: Filter paper Wax myrtle leaves Treated surface Control surface
Methods – Mosquito videotaping Assay cage Camera
Methods – Sand fly videotaping Camera Assay cage
Preliminary Conclusions • Mosquitoes were more sensitive than sand flies to pesticide-treated substrates • Repellent responses were stronger to treated filter paper than to treated leaves which likely reflects a higher dose on the filter paper • Landing responses were least affected by lambdacyhalothrin and most decreased by permethrin
Acknowledgements CMAVE Gary Clark Miriam Cooperband (USDA/APHIS) Erin Vrzal Fran Ellison William Jany, Clarke Mosquito Control Larry Pitts Eric Paulsen Lee Cohnstaedt This study was supported in part by funds from the Deployed War-Fighter Protection Research Program from the U.S. Department of Defense through the Armed Forces Pest Management Board to the Agricultural Research Service of the U.S. Department of Agriculture.