Molecular identification of bloodmeals and species composition in Culicoides biting midges

Investigations of host preferences in haematophagous insects, including Culicoides biting midges (Diptera: Ceratopogonidae), are critical in order to assess transmission routes of vector‐borne diseases. In this study, we collected and morphologically identified 164 blood‐engorged Culicoides females caught in both light traps and permanent 12‐m high suction traps during 2008–2010 in Sweden. Molecular analysis of the mitochondrial cytochrome c oxidase subunit I (COI) gene in the biting midges was performed to verify species classification, discern phylogenetic relationships and uncover possible cryptic species. Bloodmeal analysis using universal vertebrate cytochrome b primers revealed a clear distinction in host selection between mammalophilic and ornithophilic Culicoides species. Host sequences found matches in horse (n = 59), sheep (n = 39), cattle (n = 26), Eurasian elk (n = 1) and 10 different bird species (n = 18). We identified 15 Culicoides species previously recorded in Scandinavia and four additional species haplotypes that were distinctly different from the described species. All ornithophilic individuals (n = 23) were caught exclusively in the suction traps, as were, interestingly, almost all mammalophilic species (n = 41), indicating that many biting midge species may be able to cover long distances after completing a bloodmeal. These results add new information on the composition of Culicoides species and their host preferences and their potential long‐distance dispersal while blood‐engorged.