Permethrin resistance associated with inherited genes in a near-isogenic line of Musca domestica.

BACKGROUND Permethrin has been used frequently in control of Musca domestica worldwide including Pakistan, with reports of resistance development in different field strains. A near-isogenic line of M. domestica with permethrin resistance (Perm-R) was constructed to elucidate mode of inheritance and cross-resistance analyses. RESULTS Toxicity responses of reciprocal progenies F1 and F1' revealed no significant difference in their LD50 values, suggesting that permethrin resistance was inherited in an autosomal fashion with neither sex linkage nor maternal effects in the Perm-R strain of M. domestica. The values of degree of dominance were 0.6 and 0.7 for F1 and F1' progenies, respectively, which suggest that permethrin resistance was expressed as incompletely dominant trait. Chi-square analyses for the self-bred (F2), and backcross progenies (BC1, BC2, BC3, and BC4) revealed significant differences between the observed and expected mortality, indicating the possibility of multiple genes responsible for permethrin resistance. Moreover, the Perm-R strain did not show cross-resistance to propoxur, chlorpyrifos, profenofos, or spinetoram. CONCLUSION Permethrin resistance in the Perm-R strain of M. domestica was inherited as autosomal, incompletely dominant, and governed by more than one gene. Lack of cross-resistance between permethrin and propoxur, chlorpyrifos, profenofos, or spinetoram provides an opportunity for rotational use of these insecticides in control of M. domestica. These data could help to manage M. domestica and the permethrin resistance problem. This article is protected by copyright. All rights reserved.