Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/6/2020
Publication Date: 4/1/2020
Citation: Yee, W.L. 2020. Evaluation of Cyantraniliprole, Spinetoram, and Chromobacterium subtsugae extract in bait for killing and reducing oviposition of Rhagoletis indifferens (Diptera: Tephritidae). Journal of Economic Entomology. 113(3):1256-1362. https://doi.org/10.1093/jee/toaa056.
Interpretive Summary: Western cherry fruit fly is a major quarantine pest of cherries in western North America that is commonly controlled using a few select insecticides, but use of newer insecticides could protect potential resistance development. Personnel at the USDA-ARS laboratory in Wapato, WA compared the efficacies of the newer diamide insecticide cyantraniliprole with that of spinetoram and a bacterium insecticide, alone and mixed in food, against the fly. It was found that cyantraniliprole in food was as effective as spinetoram alone or in food for killing flies even though cyantraniliprole alone was less effective, while the bacterium insecticide was relatively ineffective. Results are important in that they suggest cyantraniliprole could be included in fly control programs to prevent or delay potential resistance development of flies to older insecticides.
Technical Abstract: Diamides are a relatively new class of insecticides that appears effective in controlling tephritid fruit flies. Here, the main objective was to compare efficacies of the diamide cyantraniliprole with that of spinetoram and the biopesticide Chromobacterium subtsugae extract, either alone or mixed in sucrose-yeast extract food, against western cherry fruit fly Rhagoletis indifferens Curran (Diptera: Tephritidae) in the laboratory. Flies were exposed to dry drops of insecticide treatments in dishes, and fly mortality and oviposition recorded. When alone, spinetoram caused significantly greater mortality than cyantraniliprole, but in food, cyantraniliprole and spinetoram caused similarly high mortality. Cyantraniliprole alone caused significantly lower mortality than cyantraniliprole in food, while spinetoram alone and in food caused similar mortality. Chromobacterium subtsugae extract alone or in food usually did not cause mortality higher than controls. Spinetoram alone reduced oviposition significantly more than cyantraniliprole alone, but when in food, the opposite occurred, as cyantraniliprole in food reduced oviposition significantly more than spinetoram in food. Cyantraniliprole alone reduced oviposition significantly less than cyantraniliprole in food, but spinetoram alone and in food reduced oviposition similarly. Cyantraniliprole and spinetoram in food caused significantly greater mortality in the absence than presence of a food strip, but there was no corresponding reduction in oviposition. Chromobacterium subtsugae extract had no effect on oviposition levels. Results indicate that kill and oviposition reduction of R. indifferens using cyantranilirpole is most efficacious when it is in food, in contrast to use of spinetoram, at least in the form or type used in this study.