| Abstrakt: |
Simple Summary: Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is an important invasive pest of small soft-skinned fruits globally. The combined application of insecticides and natural enemies can effectively control D. suzukii and reduce chemical insecticide residues. The pupal parasitoid Trichopria drosophilae (Hymenoptera: Diapriidae) has been evaluated as a biological agent of D. suzukii. However, little is known about the toxicity of common insecticides in T. drosophilae. Thus, this study assessed the toxicity of eight common insecticides against D. suzukii in fruit orchards and the effects of semilethal and sublethal doses on T. drosophilae. Emamectin benzoate, spinetoram, lambda-cyhalothrin, abamectin, and sophocarpidine showed high toxicity in adults and larvae of D. suzukii. The toxicities of lambda-cyhalothrin and imidacloprid in T. drosophilae adults were higher than those of the other six insecticides. Exposure to chlorantraniliprole, emamectin benzoate, sophocarpidine, abamectin, azadirachtin, and spinetoram at semilethal and sublethal doses decreased the parasitism of T. drosophilae or eclosion of the next generation. In conclusion, some insecticides at the recommended dose applied for D. suzukii had no effect on the survival of T. drosophilae adults, but insecticide residues can affect T. drosophilae development. The pupal parasitoid Trichopria drosophilae (Hymenoptera: Diapriidae) has been evaluated as a biological agent of Drosophila suzukii. Integrated pest management strategies mostly rely on combined application of multiple insecticides and natural enemies. This study assessed the toxicity of eight common insecticides against D. suzukii in fruit orchards and the effects of semilethal and sublethal doses on T. drosophilae. The eight insecticides had higher toxicities to D. suzukii larvae with lower LC50 values than those for adults. Adults and larvae showed high susceptibility to emamectin benzoate, spinetoram, lambda-cyhalothrin, abamectin, and sophocarpidine. The median lethal doses (LC50) of lambda-cyhalothrin and imidacloprid to T. drosophilae adults were 60.41 mg/L and 100.58 mg/L, higher than the toxicities of the other six insecticides. Applying chlorantraniliprole, emamectin benzoate, sophocarpidine, abamectin, azadirachtin, and spinetoram resulted in low toxicity to D. suzukii pupae. However, the exposure of D. suzukii pupae or larvae to these insecticides at semilethal and sublethal doses decreased the parasitism or eclosion rate of T. drosophilae. These results improve our understanding of the effects of insecticide residues on T. drosophilae development and provide a basis for the combined use of chemical and biological options for managing D. suzukii. [ABSTRACT FROM AUTHOR] |
