Evaluation of Cyantraniliprole, Spinetoram, and Chromobacterium subtsugae Extract in Bait for Killing and Reducing Oviposition of Rhagoletis indifferens (Diptera: Tephritidae).

Abstract

Insecticides mixed in sugar-protein baits or insecticides alone have been used to control tephritid fruit flies for many years. Here, effects of cyantraniliprole, spinetoram, and the biopesticide Chromobacterium subtsugae extract in sucrose-yeast extract bait or alone on kill and oviposition of western cherry fruit fly, Rhagoletis indifferens Curran (Diptera: Tephritidae), were evaluated in the laboratory. Flies were exposed to dry insecticide bait or insecticide alone in the presence or absence of a nontoxic food strip. Spinetoram alone caused greater mortality than cyantraniliprole alone, while cyantraniliprole in bait caused mortality as high as spinetoram bait and greater mortality than cyantraniliprole alone. Chromobacterium subtsugae extract alone but not in bait caused significant mortality compared with controls, but was much less effective than cyantraniliprole and spinetoram. Spinetoram alone reduced oviposition more than cyantraniliprole alone. However, cyantraniliprole bait reduced oviposition as much or more than spinetoram alone or spinetoram bait. Cyantraniliprole and spinetoram baits caused greater mortality when a nontoxic food strip was absent than present, but there was no corresponding reduction in oviposition. Chromobacterium subtsugae extract did not significantly reduce oviposition compared with controls. Potential benefits of using cyantraniliprole baits as an additional or alternative method to using more toxic spinosyn insecticides for controlling R. indifferens warrant study.