Li Cui1, Qinqin Wang1, Haoliang Qi1, Qiyuan Wang1, Huizhu Yuan1, Changhui Rui1. 1. Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China.
Abstract
BACKGROUND: The cotton bollworm Helicoverpa armigera is a worldwide insect pest with the ability to develop resistance to many insecticides. Indoxacarb, a sodium channel blocker, is an important insecticide that is used to control H. armigera. Cross-resistance, metabolic mechanisms and life history traits were established for an indoxacarb-selected (IND-SEL) population of H. armigera. RESULTS: After 11 generations of selection, the susceptibility to indoxacarb was decreased by 4.43-fold and the estimated realized heritability (h2 ) was only 0.072. Interestingly, the IND-SEL population was more susceptible to methoxyfenozide and abamectin than the susceptible population. The activities of cytochrome P450 monooxygenase (P450) and carboxyl esterase (CarE) were significantly increased in IND-SEL H. armigera. Thus, susceptibility to indoxacarb was increased by piperonyl butoxide and S,S,S-tributyl phosphorothioate, showing synergistic ratios of 2.54- and 1.82-fold, respectively. Moreover, the IND-SEL population had a reduced relative fitness (0.67), with a lower growth rate and fecundity than the susceptible population. CONCLUSIONS: Evidence from this study suggests that decreased susceptibility to indoxacarb may be associated with fitness costs in H. armigera and enhanced activities of P450 and CarE may be important detoxification mechanisms in the development of indoxacarb resistance. Methoxyfenozide and abamectin can be rotationally used to manage indoxacarb resistance.
BACKGROUND: The cotton bollwormHelicoverpa armigera is a worldwide insect pest with the ability to develop resistance to many insecticides. Indoxacarb, a sodium channel blocker, is an important insecticide that is used to control H. armigera. Cross-resistance, metabolic mechanisms and life history traits were established for an indoxacarb-selected (IND-SEL) population of H. armigera. RESULTS: After 11 generations of selection, the susceptibility to indoxacarb was decreased by 4.43-fold and the estimated realized heritability (h2 ) was only 0.072. Interestingly, the IND-SEL population was more susceptible to methoxyfenozide and abamectin than the susceptible population. The activities of cytochrome P450 monooxygenase (P450) and carboxyl esterase (CarE) were significantly increased in IND-SEL H. armigera. Thus, susceptibility to indoxacarb was increased by piperonyl butoxide and S,S,S-tributyl phosphorothioate, showing synergistic ratios of 2.54- and 1.82-fold, respectively. Moreover, the IND-SEL population had a reduced relative fitness (0.67), with a lower growth rate and fecundity than the susceptible population. CONCLUSIONS: Evidence from this study suggests that decreased susceptibility to indoxacarb may be associated with fitness costs in H. armigera and enhanced activities of P450 and CarE may be important detoxification mechanisms in the development of indoxacarb resistance. Methoxyfenozide and abamectin can be rotationally used to manage indoxacarb resistance.
Authors: Dionei Schmidt Muraro; Thaini M Gonçalves; Douglas Amado; Marcelo F Lima; Holly J R Popham; Paula G Marçon; Celso Omoto Journal: Insects Date: 2022-09-09 Impact factor: 3.139