Toxicities and sublethal effects of seven neonicotinoid insecticides on survival, growth and reproduction of imidacloprid-resistant cotton aphid, Aphis gossypii

摘要

BACKGROUND: Imidacloprid has been a major neonicotinoid insecticide for controlling Aphis gossypii (Glover) (Homoptera: Aphididae) and other piercing-sucking pests. However, the resistance to imidacloprid has been recorded in many target insects. At the same time, cross-resistance of imidacloprid and other insecticides, especially neonicotinoid insecticides, has been detected.RESULTS: Results showed that the level of cross-resistance was different between imidacloprid and tested neonicotinoid insecticides (no cross-resistance: dinotefuran, thiamethoxam and clothianidin;;a 3.68-5.79-fold cross-resistance: acetamiprid, nitenpyram and thiacloprid). In the study of sublethal effects, imidacloprid at LC_(20) doses could suppress weight gain and honeydew excretion, but showed no significant effects on longevity and fecundity of the imidacloprid-resistant cotton aphid, A. gossypii. However, other neonicotinoid insecticides showed significant adverse effects on biological characteristics (body weight, honeydew excretion, longevity and fecundity) in the order of dinotefuran > thiamethoxam and clothianidin > nitenpyram > thiacloprid and acetamiprid.CONCLUSION: The results indicated that dinotefuran is the most effective insecticide for use against imidacloprid-resistant A. gossypii. To avoid further resistance development, the use of nitenpyram, acetamiprid and thiacloprid should be avoided on imidacloprid-resistant populations of A. gossypii.