Study on Toxicity of Azadirathtin and Rotenoid and Their Admixture Against Spodoptera Iitura F.

The toxicity of azadirachtin and rotenone and their admixture against the 3rd-instar larvae of Spodoptera litura F.were conducted in laboratory.The results showed that azadirachtin and rotenone enhanced their toxicity with increase of the dosage.For the admixture,the optimum proportion for contact toxicity was 2∶6 when azadirachitin and rotenone concentration was 200(μg/mL) and 100(μg/mL) respectively.On this condition the co-toxicity coefficient was up to 423.15.The admixture produced a maximum anti-feeding effect and the AFC_(50) was 1.2(mg/L) when the admixture was blended with azadirachitin and rotenone at the ratio of 3∶5.The admixture at 35(mg/L) could inhibit the larvae growth by more than 90%.