Abstract: The combinative rate measurement of (3-[I125] iodotyrosyl) α-bungarotoxin was applied in the analysis of the relation between nerve acetylcholine receptor and three types of insecticide resistance in diamondback moth, Plutella xylostella (L.). In the dimehypo resistant strain and the cartap resistant strain, the nerve acetylcholine receptor shown remarkable insensitivity to dimehypo and cartap, their binding rate to ligand was about 66% and 60% of the susceptible strain, respectively. The sensitivity to deltamethrin in the deltamethrin resistant strain did not show visible change. These results indicated that the decline in the sensitivity of nerve acetylcholine receptor to insecticide might be a potential mechanism to nereistoxin insecticides resistance in the diamondback moth.

Key words: diamondback moth, dimehypo, cartap, nerve acetylcholine receptor, insecticide resistance