Acute Toxicity of Chlorpyrifos to Silkworm (Bombyx mori)

Acute toxicity of chlorpyrifos to silkworm in different situations were conducted.For second-instar,third-instar,fourth-instar and fifth-instar larvae,LC_(50)(48 h,25 ℃)of chlorpyrifos to silkworm was 1.11,1.73,3.48 and 4.12 mg/L,respectively.When environmental temperature was 20,25,30 and 35 ℃,LC_(50)(48 h)to third-instar larvae was 1.70,1.80,0.49 and 0.40 mg/L,respectively.When immersion time of mulberry leaves in chlorpyrifos solution was 1 s,10 s,1 min,10 min and 1 h,LC_(50)(48 h,25 ℃)to fourth-instar larvae was 5.55,3.64,3.15,2.12 and 1.54 mg/L,respectively.After contact of silkworm with filter paper treated by chlorpyrifos solution in time of 1,10,30 and 60 min,LC_(50)(48 h,25 ℃)to third-instar larvae was 3.59,0.28,0.20 and 0.12 μg/cm~(2),respectively.