One of the most effective ways of managing adult mosquitoes that vector human and animal pathogens is the use of ultra-low-volume (ULV) insecticides. Because of the lack of environmental fate studies and concerns about the safety of the insecticides used for the management of adult mosquitoes, we conducted an environmental fate study after truck-mounted applications of permethrin and naled. One...

Although synergism between pesticides has been widely documented, the physiological mechanisms by which an insecticide synergizes another remains unclear. Toxicological and electrophysiological studies were carried out on two susceptible pest species (the mosquito Culex quinquefasciatus and the cockroach Periplaneta americana) to understand better the physiological process involved in pyrethroi...

Three studies were conducted to evaluate the effectiveness of insecticide-impregnated ear tags in controlling face flies, Musca autumnalis DeGeer, and horn flies, Haematobia irritans (Linn.), on pastured beef cattle. In one 16-week trial, polyvinyl chloride (PVC) ear tags treated with stirofos (Rabon) insecticide reduced horn fly numbers by 79% (P less than .05) and face fly numbers by 30% (P l...

A trial to determine the effectiveness of sisal eaves-curtains impregnated with permethrin for malaria control was conducted in the malaria holoendemic western Kenya between 1991 and 1993. Indoor resting densities of Anopheles gambiae s.l. and Anopheles funestus were reduced by 90.9% and 93.8% respectively in protected houses. The entomological inoculation rate (EIR) was reduced by 72% in the i...

INTRODUCTION Tick-borne diseases such as Lyme disease, Rocky Mountain spotted fever, and ehrlichiosis are a significant concern for many thousands of workers who have frequent and unavoidable exposure to tick-infested habitats. Many North Carolina state employees with outdoor occupations report multiple tick bites each year, indicating that existing tick preventive strategies may be underutiliz...

The efficacy of insecticide mixtures of permethrin (pyrethroid) and propoxur (carbamate) was tested by larval bioassays on two strains of Culex quinquefasciatus (Say), one resistant to pyrethroids and the other resistant to carbamates. The method consisted in combining one insecticide at the highest concentration causing no mortality (LC0) with increasing concentrations of the second one. The c...

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...

Resistance in a dual malathionand permethrin-resistant head louse strain (BR-HL) was studied. BR-HL was 3.6and 3.7-fold more resistant to malathion and permethrin, respectively, compared to insecticide-susceptible EC-HL. S,S,S-Tributylphosphorotrithioate synergized malathion toxicity by 2.1-fold but not permethrin toxicity in BR-HL. Piperonyl butoxide did not synergize malathion or permethrin t...

Permethrin is a widely used pyrethroid insecticide for which the toxicokinetics of exposure biomarkers in humans is not fully documented. The time courses of key biomarkers of permethrin exposure were thus assessed in accessible biological matrices of orally exposed volunteers. Six volunteers ingested 0.1 mg/kg body weight of permethrin (60:40 trans/cis). Blood samples were withdrawn at fixed p...

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...