title: Culicoides species associated with sheep in the Netherlands and the effect of a permethrin insecticide.
abstract: Culicoides spp. act as vectors for a number of viral diseases of animals including bluetongue in sheep. The aims of this study were to determine: (1) which Culicoides spp. are associated with sheep in The Netherlands; (2) the time of the day when they are most active; and (3) the effect of treatment of animals with a permethrin insecticide. Two pairs of sheep were each housed within mosquito tents of either one or two layers of netting and all trapped Culicoides spp. were identified microscopically. For the permethrin insecticide study, one of two pairs of sheep was treated with 3.6% permethrin and all animals were housed in tents of similar design. Of the 6210 midges captured, 54.1% were identified as C. chiopterus and 42.7% as C. obsoletus. C. imicola was not identified. The average insect feeding rate was 35-40% and midge activity was greatest around sunset. Permethrin treatment reduced the number of midges captured by 50% and also resulted in a decrease in the percentage of midges that had fed. The findings provide useful information on the behaviour and distribution of Culicoides spp. that will facilitate the development of appropriate control strategies to minimise the risk of insect-vector borne virus diseases such as bluetongue.
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Yalelaan 114, 3584 CM Utrecht, The Netherlands.
authors.forename: Karien
authors.initials: K
authors.lastname: Griffioen
authors.affiliation: Department of Farm Animal Health Management, Faculty of Veterinary Medicine, Yalelaan 7, 3584 CL Utrecht, The Netherlands.
authors.forename: Dennis B J
authors.initials: DBJ
authors.lastname: van Gemst
authors.affiliation: Department of Farm Animal Health Management, Faculty of Veterinary Medicine, Yalelaan 7, 3584 CL Utrecht, The Netherlands.
authors.forename: Maarten C
authors.initials: MC
authors.lastname: Pieterse
authors.affiliation: Laboratory of Entomology, Wageningen University, PO Box 8031, 6700 EH Wageningen, The Netherlands.
authors.forename: Frans
authors.initials: F
authors.lastname: Jacobs
authors.affiliation: Department of Equine Sciences, Faculty of Veterinary Medicine, Yalelaan 114, 3584 CM Utrecht, The Netherlands. Electronic address: m.sloet@uu.nl.
authors.forename: Marianne M
authors.initials: MM
authors.lastname: Sloet van Oldruitenborgh-Oosterbaan
mesh_terms: D000818:Animals; D058448:Biota; D001819:Bluetongue / Q000469:parasitology / Q000517:prevention & control*; D002519:Ceratopogonidae / Q000502:physiology; D005247:Feeding Behavior; D005260:Female; D007303:Insect Vectors / Q000502:physiology; D007306:Insecticides; D008297:Male; D009426:Netherlands; D026023:Permethrin; D016012:Poisson Distribution; D012756:Sheep
chemical_list: D007306:Insecticides; D026023:Permethrin