Temperature-dependent variations in toxicity of diamide insecticides against three lepidopteran insects.

The effect of temperature on the toxicities of four diamide insecticides (chlorantraniliprole, cyantraniliprole, flubendiamide, tetraniliprole) against three lepidopteran insects (Helicoverpa armigera, Plutella xylostella, Athetis lepigone) were determined from 15 to 35 degrees C by exposing third-instar larvae to dip-treated cabbage leaf. The results indicated that increase in temperature led to an increase significantly and regularly in the toxicities of the four diamide insecticides against P. xylostella and H. armigera, but not for A. lepigone. The temperature coefficients (TCs) of the four diamide insecticides increased from 15 to 35 degrees C. Tetraniliprole for H. armigera (+825.83), chlorantraniliprole for P. xylostella (+315.65) and cyantraniliprole for H. armigera (+225.77) exhibited high positive TCs. For A. lepigone, temperature had a positively weak or no effect on the toxicities of most of the diamide insecticides from 20 to 30 degrees C, but a higher effect from 30 to 35 degrees C. In addition, the toxicities of chlorantraniliprole, cyantraniliprole and tetraniliprole all decreased from 15 to 20 degrees C. This study can guide pest managers in choosing suitable ambient field temperature when spraying diamide insecticides against lepidopteran insects.