MECHANISM OF TOXICITY OF BIOLOGICAL PESTICIDE GCSC-BTA AGAINST PLUTELLA XYLOSTELLA L.

GCSC-BtA was composed of Bt-crystal toxin and Avermectin, and had similar mechanism of toxicity to Avermectin against Plutella xylostella. Both BtA and Avermectin had contact poison and stomach poison and had not systemic toxicity and fumigant toxicity. However Bt-crystal toxin had only stomach poison. Contact poison of 1mg/mL BtA against P. xylostella in 72h leaded to mortality of 36.7%, higher than that of Avermectin (20.0%). Stomach toxicities of BtA, Bt-crystal toxin and Avermectin against P. xylostella in 48h were 0.0136mg/mL, 0.0059mg/mL and 0.7274mg/mL of LC 50 respectively.