Species composition of Culicoides (Diptera: Ceratopogonidae) in the western United States

Culicoides (Diptera: Ceratopogonidae) are small (1-5mm), haematophagous diptera with about 1,000 known extant species globally. In North America, there are 151 recognized species within 13 subgenera and seven species groups. These species are known to inhabit diverse habitats across a broad geographic range. However, for many species, the extent to which their geographic range reaches is unknown. This knowledge gap is especially acute in locations where animal production is not prevalent and for Culicoides species that do not play an important role in pathogen transmission. Current research has also shown that known distributions of species may be misrepresented due to the presence of cryptic species.



The purpose of this study is to: (1) identify Culicoides species present in the western United States, and (2) model the distribution of species identified in (1) above. Culicoides in the western U.S. were captured as by-catch (non-target species) by partner agencies including mosquito and vector control districts and NSF-funded National Ecological Observatory Network (NEON) researchers and then shipped to UC Riverside for further processing. By-catch samples received at UCR were sorted to family and genus, with Culicoides further sorted into morphologically similar groups. A subset of individuals from each morphologically similar group were identified to species using published keys to Culicoides in North America and then further identified using molecular means. Species distributions in the western USA were modeled to geographical and environmental characteristics of collection sites to evaluate species distributions.