Toxicity Evaluation of Twenty-seven Pesticides to Bombyx mori

The acute toxicity of twenty-seven pesticides to silkworm, Bombyx mori L., was evaluated in laboratory using Leaf dipping method; the grade was compartmentalized according as toxicity scope and the safety evaluation was made for these pesticides. The results indicate that the LC_(50 ) of two insecticides is lower than 0.1 mg/L(belong to special high toxicity grade); that of eight (insecticides) between 0.1~10 mg/L(belong to high toxicity grade); that of seven pesticides between( 10~1 000 mg/L)(belong to middling toxicity grade; that of ten pesticides higher than 1 000 mg/L((belong to low toxicity grade)). And the method of toxicity determining of pesticide to silkworm was discussed.