Cross-resistance and Fitness Cost Analysis of Resistance to Thiamethoxam in Melon and Cotton Aphid (Hemiptera: Aphididae)

摘要: The melon/cotton aphid, Aphis gossypii Glover, is a notorious pest in many crops. neonicotinoid insecticide thiamethoxam widely used for A. control. To evaluate resistance risk, aphid strain with an extremely high level of to (>2,325.6-fold) was established after selection 24 generations. Additionally, the cross-resistance pattern other neonicotinoids and fitness were analyzed. results showed thiamethoxam-resistant had levels against clothianidin (>311.7-fold) nitenpyram (299.9-fold), dinotefuran (142.3-fold) acetamiprid (76.6-fold), low imidacloprid (9.3-fold). Compared life table susceptible strain, relative 0.950, significant decreases oviposition days fecundity prolonged developmental duration. molecular mechanism costs studied by comparing mRNA expression juvenile hormone acid O-methyltransferase (JHAMT), hormone-binding protein (JHBP), epoxide hydrolase (JHEH), ecdysone receptor (EcR), ultraspiracle (USP), Vitellogenin (Vg) strains. Significant overexpression JHEH JHBP downregulation EcR Vg found strain. These indicate that has potential develop continuous exposure, considerable cost neonicotinoids.