Inheritance of Permethrin Resistance in Culex quinquefasciatus

Abstract

The toxicity of permethrin to different life stages of Culex quinquefasciatus (Say) was examined in three field insecticide resistant strains, HAmCq(G0), MAmCq(G0), and BAmCq(G0); two permethrin selected strains, HAmCq(G8) and MAmCq(G6); and a laboratory susceptible strain, S-Lab. The levels of tolerance to permethrin differed among the developmental stages of Culex mosquito larvae with an ascending order from first to fourth instar. A developmentally regulated pattern of permethrin resistance in Culex mosquito larvae was identified, once again increasing from first to fourth instar. Adult mosquitoes had relatively lower levels of resistance in general compared with their larval stages, suggesting that different mechanisms may be involved in the response to insecticide selection pressure between larvae and adults. Inheritance of resistance to permethrin was examined using reciprocal crosses between resistant HAmCq(G8) and susceptible S-Lab strains; the resulting logarithm concentration-probit response curves for reciprocal F1 lines were similar to those for the susceptible strain, with degree of dominance values of -0.2 to -0.3, suggesting that the inheritance of permethrin resistance in Cx. quinquefasciatus is incompletely recessive. No significant difference was found in the values of LC50 and the slope of the log concentration-probit lines between reciprocal F1 lines, indicating that the resistance to permethrin was inherited autosomally. Both chi2 goodness-of-fit test and log concentration-probit line analysis on responses of backcross and self-bred progeny to permethrin indicated that permethrin resistance in the HAmCq(G8) strain did not follow a monogenic gene inheritance model, revealing that permethrin resistance in Cx. quinquefasciatus is controlled by more than one gene.

Current Susceptibility Status of MalaysianCulex quinquefasciatus(Diptera: Culicidae) Against DDT, Propoxur, Malathion, and Permethrin

“…The occurrence of these incidences might be because of the differences between the insecticide resistance gene expression in larval and adult stages. A number of studies have indicated that insecticide resistance is more accentuated in the larval stage Selvi et al 2006Selvi et al , 2007Li and Liu 2010), while a lack of expression was observed in the adult stage (Huchard et al 2006). However, higher levels of insecticide resistance in the adult stage also have been observed (Chavasse and Yap 1997).…”

Cis-acting mutation and duplication: History of molecular evolution in a P450 haplotype responsible for insecticide resistance in Culex quinquefasciatus

“…Recently, Li and Liu (2010) found strong larval resistance against permethrin in C. quinquefasciatus populations collected in the United States in the 2000s. According to their study, the resistance in those populations showed significant reduction in the adult stage which is the characteristic identical to the resistance in JPP.…”

Global spread and genetic variants of the two CYP9M10 haplotype forms associated with insecticide resistance in Culex quinquefasciatus Say

“…Pyrethroid insecticides are usually used to combat adult mosquitoes in the field. However, the resistance associated with the D-Cu( þ ) and Cu( þ ) haplotypes decreases markedly in the adult stage, because the overexpression of CYP9M10 almost halts after the larval stage (Hardstone et al, 2007;Komagata et al, 2010;Li and Liu, 2010;Itokawa et al, 2011). Although nontargeted organisms, such as Drosophila (Catania et al, 2004;Schlenke and Begun, 2004), could be subject to selective pressure of insecticides, perhaps as off-target victims of agricultural pesticide usage (Antonio-Nkondjio et al, 2011), it is unclear how often in the field C. quinquefasciatus encounters aquatic environments with high pyrethroid concentrations, where the D-Cu( þ ) haplotype is advantageous over Cu( þ ) haplotypes.…”