Elevated expression of esterase and cytochrome P450 are related with lambda–cyhalothrin resistance and lead to cross resistance in Aphis glycines Matsumura

•High level resistance to lambda–cyhalothrin was developed in laboratory-selected stain of A. glycines.•PBO, DEF and TPP significantly increased the toxicity of lambda–cyhalothrin in the resistant strain.•The expression levels of CarE, E4 esterase and P450s significantly increased in the resistant strain.•Increased expression of esterase and P450 cause cross-resistance to other insecticides. A resistant strain of the Aphis glycines Matsumura (CRR) has developed 76.67-fold resistance to lambda–cyhalothrin compared with the susceptible (CSS) strain. Synergists piperonyl butoxide (PBO), S,S,S-Tributyltrithiophosphate (DEF) and triphenyl phosphate (TPP) dramatically increased the toxicity of lambda–cyhalothrin to the resistant strain. Bioassay results indicated that the CRR strain had developed high levels of cross-resistance to chlorpyrifos (11.66-fold), acephate (8.20-fold), cypermethrin (53.24-fold), esfenvalerate (13.83-fold), cyfluthrin (9.64-fold), carbofuran (14.60-fold), methomyl (9.32-fold) and bifenthrin (4.81-fold), but did not have cross-resistance to chlorfenapyr, imidacloprid, diafenthiuron, abamectin. The transcriptional levels of CYP6A2-like, CYP6A14-like and cytochrome b-c1 complex subunit 9-like increased significantly in the resistant strain than that in the susceptible. Similar trend were observed in the transcripts and DNA copy number of CarE and E4 esterase. Overall, these results demonstrate that increased esterase hydrolysis activity, combined with elevated cytochrome P450 monooxygenase detoxicatication, plays an important role in the high levels of lambda–cyhalothrin resistance and can cause cross-resistance to other insecticides in the CRR strain.