Cross‐resistance spectrum in pyrethroid‐resistantCulex quinquefasciatus

摘要

AbstractStrains ofCulex quinquefasciatusSay, selected with biopermethrin (1R)‐trans‐permethrin or with (1R)‐cis‐permethrin, were examined in the larval stage for crossresistance to 30 pyrethroids, DDT, dieldrin, temephos, propoxur, and two organotin compounds. The (1R)‐trans‐Permethrin‐R strain resistance factor (RF) = 4100‐fold and the (1R)‐cis‐Permethrin‐R strain (RF= 450‐fold) ofC. quinquefasciutuswere cross‐resistant to all pyrethroids tested RF= 12‐fold for an allethrin isomer to about 6000‐fold for (RS,RS)‐fenvalerate as well as to DDT (RF= about 2000‐fold). However, they were not significantly Cross‐resistant to dieldrin, temephos, propoxur, and the two organotin compounds. Changes in the alcohol moiety, structural isomerism, and susceptibility of the cyclopropane C‐3 side chain to oxidative attack are important factors in determining the level of cross‐resistance to various pyrethroids. Limited synergism of the pyrethroids byS,S,S‐tributyl phosphorotrithioate and piperonyl butoxide (PB), and of DDT by chlorfenethol and PB, suggested that some non‐metabolic mechanism, such askdr, may be an important component of resistance to pyr