BACKGROUND Pyrethroid insecticides are the most commonly used residential insecticides in the United States. OBJECTIVES Our objective was to assess human exposure via biomonitoring to pyrethroid insecticides in a representative sample of the general U.S. population >or= 6 years of age. METHODS By using isotope-dilution high-performance liquid chromatography/electrospray chemical ionization/...

Triatomine insects are vectors of the protozoan Trypanosoma cruzi , causative agent Chagas disease. Although residual pyrethroid spraying has been a successful vector control strategy for many years, growing number pyrethroid-resistance foci is being documented, mainly in Triatoma infestans that led to failures elimination. Insecticide resistance multifactorial phenomenon often implies combinat...

Cochliomyia hominivorax larvae are known for their parasitic habit in living vertebrates, causing considerable economic losses to livestock industry. This ectoparasite has been controlled mainly by applying insecticides, but this method usually results in the selection of resistant individuals. The resistance mechanism known as knockdown resistance (kdr) is a generic term for amino acid substit...

Two mutations have been found in five closely related insect esterases (from four higher Diptera and a hymenopteran) which each confer organophosphate (OP) hydrolase activity on the enzyme and OP resistance on the insect. One mutation converts a Glycine to an Aspartate, and the other converts a Tryptophan to a Leucine in the enzymes' active site. One of the dipteran enzymes with the Leucine mut...

A novel pyrethroid-degrading esterase gene pytY was isolated from the genomic library of Ochrobactrum anthropi YZ-1. It possesses an open reading frame (ORF) of 897 bp. Blast search showed that its deduced amino acid sequence shares moderate identities (30% to 46%) with most homologous esterases. Phylogenetic analysis revealed that PytY is a member of the esterase VI family. pytY showed very lo...

Anopheles funestus, one of the main African malaria vectors, caused a major malaria outbreak in South Africa during 1999/2000, even though South Africa had an effective vector control program in place. The outbreak was due to pyrethroid resistant An. funestus invading KwaZulu/Natal. Increased activity of cytochrome P450 (monooxygenase) was responsible for the pyrethroid resistance in this speci...

Five BC₁ lines and 16 house fly mass-cross homozygous lines were generated from crosses of the pyrethroid resistant ALHF (wild-type) and susceptible aabys (bearing recessive morphological markers on each of five autosomes) strains. Each of the resulting homozygous lines had different combinations of autosomes from the resistant ALHF strain. Levels of resistance to permethrin were measured for e...

Paresthesias have previously been reported among adults in occupational and non-occupational settings after dermal contact with pyrethroid insecticides. In this report, we describe a preverbal 13-month-old who presented to his primary care pediatrician with approximately 1 week of odd facial movements consistent with facial paresthesias. The symptoms coincided with a period of repeat indoor spr...

A total of 53 strains of onion thrips, Thrips tabaci Lindeman, were established, of which 14 strains were collected from persimmon fruit and 39 strains from a vetch weed, Vicia angustifolia, in commercial persimmon orchards in Wakayama Prefecture. Susceptibility to insecticides was evaluated by the Petri dish-spraying tower method. Pyrethroid-resistant strains and pyrethroid-susceptible strains...

Owing to the spread of pyrethroid resistance in Anopheles gambiae s.s. (Diptera: Culicidae) and other vector mosquitoes, there is an urgent need to develop alternative insecticides to supplement the pyrethroids for malaria control. Indoxacarb is an oxadiazine insecticide initially commercialized by DuPont for control of agricultural pests. Performance against An. gambiae bearing kdr (pyrethroid...