Culicoides (Diptera: Ceratopogonidae) and livestock in the Netherlands: comparing host preference and attack rates on a Shetland pony, a dairy cow, and a sheep.

Culicoides (Diptera: Ceratopogonidae) host preferences and attack rates were quantified in early summer at a dairy farm in the Netherlands using livestock tethered at pasture. Midges were aspirated hourly over seven consecutive hours (17:00-23:00) from a dairy cow, a Shetland pony, and a sheep and correspondingly yielded seventeen, thirteen, and nine species. Of the 14,181 midges obtained, approximately 95% belonged to the C. obsoletus complex, C. dewulfi, C. chiopterus, and C. punctatus that together include all proven or potential vectors for arboviral diseases in livestock in northwestern Europe. On average, 7.6 and 3.5 times more Culicoides were collected, respectively, from the cow and the Shetland pony than from the sheep. In descending order of abundance, the C. obsoletus complex, C. dewulfi, and C. chiopterus dominated attacks on all three hosts, whereas C. punctatus and C. pulicaris favored only the two larger hosts. Irrespective of the host species involved, the three body regions attracted the same component species, C. chiopterus favoring the legs, C. punctatus and C. achrayi the belly, and the C. obsoletus complex, C. dewulfi, and C. pulicaris the head, back, and flanks. That known and potential vectors for animal diseases feed indiscriminately on a broad range of mammal hosts means that all major livestock species, including equines, are rendered susceptible to one or more Culicoides-borne pathogens.