Characterization and fitness cost of bifenthrin resistance in Rhopalosiphum padi (Hemiptera: Aphididae)

Abstract

Rhopalosiphum padi is an important global wheat pest. The pyrethroid insecticide bifenthrin is widely used in the control R. padi. We explored the resistance potential, cross-resistance, adaptive costs, and resistance mechanism of R. padi to bifenthrin using a bifenthrin-resistant strain (Rp-BIF) established in laboratory. The Rp-BIF strain developed extremely high resistance against bifenthrin (1033.036-fold). Cross-resistance analyses showed that the Rp-BIF strain had an extremely high level of cross-resistance to deltamethrin (974.483-fold), moderate levels of cross-resistance to chlorfenapyr (34.051-fold), isoprocarb (27.415-fold), imidacloprid (14.819-fold), and thiamethoxam (11.228-fold), whereas negative cross-resistance was observed to chlorpyrifos (0.379-fold). The enzymatic activity results suggested that P450 played an important role in bifenthrin resistance. A super-kdr mutation (M918L) of voltage-gated sodium channel (VGSC) was found in the bifenthrin-resistant individuals. When compared with the susceptible strain (Rp-SS), the Rp-BIF strain was significantly inferior in multiple life table parameters, exhibiting a relative fitness of 0.69. Our toxicological and biochemical studies indicated that multiple mechanisms of resistance might be involved in the resistance trait. Our results provide insight into the bifenthrin resistance of R. padi and can contribute to improve management of bifenthrin-resistant R. padi in the field.

Overexpression of the Chemosensory Protein CSP7 Gene Contributed to Lambda-Cyhalothrin Resistance in the Bird Cherry-Oat Aphid Rhopalosiphum padi

“…The expression of RpCSP7 is significantly induced in the aphid after exposure to lambda-cyhalothrin. Previous studies showed that increasing expression of detoxifying enzymes and target-site VGSC mutation is related to pyrethroid resistance in this aphid. ,− In this study, we provided evidence that RpCSP7 was involved in the high resistance of R. padi to lambda-cyhalothrin.…”

“…padi to bifenthrin and deltamethrin. We speculated that the cross-resistance of the LC-RR strain to deltamethrin and bifenthrin is likely due to other resistance mechanisms, such as target-site insensitivity and increased metabolism through detoxifying enzymes. ,− …”

“…Previous studies have identified some mechanisms associated with high levels of resistance to bifenthrin and lambda-cyhalothrin in R. padi, including a target-site VGSC (voltage-gated sodium channel) M918L mutation and overexpression of cytochrome P450 monooxygenases (P450) genes or uridine diphosphate (UDP)-glycosyltransferase (UGTs) genes. ,− Additionally, a carboxylesterase (CarE) has been found to be involved in the resistance of R. padi to cyhalothrin .…”

“…padi strain (LC-RR) exhibited an extremely high resistance to lambda-cyhalothrin. Complicated resistance mechanisms, including voltage-gated sodium channel mutation and increased expression level of detoxifying enzymes, were found to contribute to the resistance. ,− However, the resistance level of the LC-RR strain was increased under the selection of lambda-cyhalothrin, indicating that some novel mechanisms may be involved in the resistance.…”

Uridine Diphosphate-Glycosyltransferase RpUGT344D38 Contributes to λ-Cyhalothrin Resistance in Rhopalosiphum padi

“…padi, namely, the λ-cyhalothrin-resistant strain LCR (previously referred to as LC-R or LC-RR) and the bifenthrin-resistant strain BTR (previously referred to as BIF). We found that the presence of M918L target-site mutations in the VGSC gene, along with increased expression of P450 (cytochrome P450) genes, contributed to the resistance observed in these two strains. − However, further exposure to pyrethroids resulted in a significant increase in the resistance ratio of R. padi to λ-cyhalothrin and bifenthrin, indicating the presence of additional mechanisms involved in the high levels of resistance of these aphids to pyrethroids.…”