Acute Toxicity of 9 Acaricides to Silkworm

With leaf dipping method,9 common acaricides were tested for determination of their acute toxicity to silkworm and observation of toxic symptom.Results showed that the LC_(50) of emamectin benzoate and abamectin to silkworm were0.000697 and 0.001 94 mg/L respectively,which were virulent toxicity.Fipronil,etoxazole and lufenuron were high toxicity,with LC_(50) 0.785,2.17 and 5.94 mg/L respectively.Above pesticides with virulent and high toxicity should be banned for silkworm area use.Chlorfenapyr and fenpyroximate were of moderate toxicity with LC_(50) 65.6 and 171.4 mg/L respectively.Spirodiclofen and fenbutatin oxide were low toxicity,and the LC_(50) were 234.0 and 261.3 mg/L respectively.However,besides the toxicity,selectivity,residual interval and other factors of a pesticide also should be considered for usage to silkworm area.