Murchie, Archie K.Thompson, Geoff M.Clawson, SamBrown, AndrewGordon, Alan WesleyJess, Stephen2020-06-052020-06-052019-08-08Murchie, A. K., Thompson, G. M., Clawson, S., Brown, A., Gordon, A. W. and Jess, S. (2019) ‘Field Evaluation of Deltamethrin and Ivermectin Applications to Cattle on Culicoides Host-Alighting, Blood-Feeding, and Emergence’, Viruses. MDPI AG, 11(8), p. 731. doi: 10.3390/v11080731.1999-4915https://doi.org/10.3390/v11080731Publication history: accepted - 2 August 2019, published - 8 August 2019The impact of topical applications of deltamethrin and ivermectin to cattle on Culicoides spp. landing and blood-feeding was studied in this work using sticky traps mounted on Friesian heifers’ backs. There was no effect of the insecticides on total numbers of Culicoides trapped or the proportion engorged. Deltamethrin and ivermectin treatment did not prevent blood-feeding on these animals. Deltamethrin did result in significant Culicoides mortality as evidenced by the numbers of dead midges combed from heifers’ upper flanks. The proximity of engorged midges on traps to dead midges in the hair suggests that blood-feeding took place despite midges receiving an ultimately lethal dose of deltamethrin. Ivermectin application resulted in a smaller proportion of nulliparous than parous females caught. There was no significant effect of ivermectin on the numbers of Culicoides that emerged from dung samples (but p was small at 0.095 for the Obsoletus group Culicoides). In cases of suspect animal imports, pour-on or spray applications of deltamethrin could reduce the risk of onward transmission of bluetongue virus.en© 2019 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) licenseculicoides, bluetongue, deltamethrin, ivermectin, sticky trapping, onward transmissionArticle