A previous study identified 3 nonsynonymous and 6 synonymous mutations in the entire mosquito sodium channel of Culex quinquefasciatus, the prevalence of which were strongly correlated with levels of resistance and increased dramatically following insecticide selection. However, it is unclear whether this is unique to this specific resistant population or is a common mechanism in field mosquito...

The expression of some insect P450 genes can be induced by both exogenous and endogenous compounds and there is evidence to suggest that multiple constitutively overexpressed P450 genes are co-responsible for the development of resistance to permethrin in resistant mosquitoes. This study characterized the permethrin induction profiles of P450 genes known to be constitutively overexpressed in re...

Two strains of Aedes aegypti, one resistant to DDT but susceptible to permethrin(RdSp), and the other resistant to both DDT and permethrin (RdRp), were established in mosquitoes collected from Chiang Mai province, northern Thailand. Comparisons with a susceptible reference strain indicated that DDT resistance in both RdSp and RdRp strains was mainly due to an increase in DDTase activity. Simila...

Field populations of tobacco budworm. Heliothis virescens (F.). have been monitored annually since 1977 with topical applications of synthetic pyrethroid insecticides (primarily permethrin) and methyl parathion to detect changes in insecticide susceptibility. These data showed that LD50's fluctuated somewhat from year to year with permethrin. but with one possible exception. the fluctuations we...

Four cytochrome P450 cDNAs, CYP6AA7, CYP9J40, CYP9J34, and CYP9M10, were isolated from mosquitoes, Culex quinquefasciatus. The P450 gene expression and induction by permethrin were compared for three different mosquito populations bearing different resistance phenotypes, ranging from susceptible (S-Lab), through intermediate (HAmCq(G0), the field parental population) to highly resistant (HAmCq(...

the susceptibility of 5 wild strains of german cockroach collected from five infected flats in tehran were assessed by tests of surface contact method to cyfluthrin, permethrin, sumithrin and lambdacyhalothrin. comparison of the result of knockdown tests on the wild strains with a standard susceptible strain indicated that all the strains are resistant to sumithrin, i.e., resistance ratio, the ...

Insecticide resistance in the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae),has been demonstrated previously, but mostly with insecticides that are no longer used, such as the organochlorines. Resistance to commonly used pyrethroids has been evaluated twice, but only in the midwestern United States. Stable fly susceptibility to a commonly used pyrethroid, permethrin, was determined i...

The susceptibility of two New Zealand populations of diamondback moth, Plutella xylostella, to insecticides from three classes was compared with the susceptibility of a standard North American population (Geneva 88) in laboratory assays at the New York Experiment Station during 1993. Leaf dip assays showed that the New Zealand populations had developed moderate resistance to permethrin compared...

BACKGROUND Increasing incidences of insecticide resistance in malaria vectors are threatening the sustainable use of contemporary chemical vector control measures. Fungal entomopathogens provide a possible additional tool for the control of insecticide-resistant malaria mosquitoes. This study investigated the compatibility of the pyrethroid insecticide permethrin and two mosquito-pathogenic fun...