Susceptibility ofCulicoidesspecies biting midges to deltamethrin-treated nets as determined under laboratory and field conditions in the Balearic Islands, Spain

Abstract Culicoides L atreille ( D iptera: C eratopogonidae) are vectors of several arboviruses, including bluetongue virus ( BTV ) and A frican horse sickness virus ( AHSV ), which cause diseases in, respectively, sheep and cattle, and horses, and have economic repercussions mainly as a result of trade restrictions. Insecticides can be used to reduce vector populations and hence the spread of disease. Despite the economic importance of these diseases, relatively few studies have evaluated the efficacy of commercially available insecticides and the effectiveness of treated nets against C ulicoides species. The aim of the present study was to evaluate the insecticidal effect of commercially available polyethylene nets ( ZeroVector ® ) treated with deltamethrin (4.4 g/kg ± 15%) on C ulicoides species. Laboratory and field trials were conducted in C ulicoides populations collected in M ajorca in the B alearic I slands, S pain. The present study shows that deltamethrin‐treated nets provoke high and rapid mortality (90–100%) in C ulicoides midges under laboratory conditions and increase mortality by 13% when deployed in the field.