The Test on Toxicity of a Newly Pesticide Chlorfenapyr to Silkworm

Chlorfenapyr is a newly synthetic arypyrrole insecticides. Acute toxicity of the pesticide to silkworms was conducted by seven grade concentration of chlorfenapyr solution :500 × (200 mg/L), 800 ×(125 mg/L),1000 × (100 mg/L),1300 × (77 mg/L),1500 × (70 mg/L),1800 × (56 mg/L),2000 × (50 mg/L) and CK. Chronic toxicity of pesticide chlorfenapyr to 3 and 4 instar silkworms was conducted by four grade consistence of chlorfenapyr solution:1000 × (100 mg/L), 1500 × (70 mg/L), 2000 × (50 mg/L), 2500 × (40 mg/L)and CK. The result shown that there was no acute toxicity of the pesticide to silkworms. Chronic accumulate toxicity was found after continued feeding the contaminated leaves resulting in the increase of dead worm cocoon percentage and the decrease of eclosion rate. There existed correlation between that and the concentration of chlorfenapyr.