Toxicity of abamectin series compounds to four important lepidopteral pests

The toxicity of abamectin and abamectin derivatives (emamectin benzoate and emamectin) to lepidopteran pests was tested in the lab. The toxicity of emamectin was the highest. Toxicity of emamectin and emamectin benzoate were 9.5-65 and 4-15 times respectively as that of abamectin. Chilo suppressalis and Plutella xylostella were very susceptable to emamectin and emamectin benzoate (LC_(50): 0.004-0.283 mg·L~(-1)); Spodoptera exigua and Helicoverpa armigera were susceptable to emamectin and emamectin benzoate (LC_(50): 1.017-(8.1081) mg·L~(-1)) , but less susceptable to abamectin (LC_(50): 18.091-65.992 mg·L~(-1)). So, the two abamectin derivatives can be used to control Spodoptera exigua and Helicoverpa armigera in field.