Residual Efficacy of Diamide Insecticides against Larvae of Summer Fruit Tortrix, Adoxophyes orana fasciata

Abstract

The residual efficacy of diamide insecticides against summer fruit tortrix larvae, Adoxophyes orana fa­sciata, was evaluated by collecting apple tree leaves at 7, 16, and 37 days after spraying, and rearing larvae on these field-aged leaves. At 7 days after spraying, diamide insecticides exhibited robust efficacy, with larval mortality of 92%–100% across all treatments. At 16 days after spraying, the efficacy varied among insecticides: flubendiamide achieved 96% mortality, tetraniliprole and chlorantraniliprole reached 87%, cyclaniliprole resulted in 57%, and cyantraniliprole achieved 16%. Flubendiamide maintained a high larval mortality rate of 92% even after 37 days. No diamide insecticide was effective when larvae were reared on leaves from terminal shoots that emerged after spraying and were collected at 16 days after spraying. The residual efficacy of diamide insecticides in the field appears to depend on the differential potency of these insecticides and the seasonal variations in apple tree shoot development.