Morphological and molecular identification of Culicoides (Diptera: Ceratopogonidae) of the southern California desert

Culicoides biting midges are vectors of important animal pathogens including bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). While some Culicoides species present in the southern California desert are implicated in the transmission of these viruses to ruminant animals, these species have not been extensively studied due in part to the challenge of identifying Culicoides in this region. In particular, there is a lack of published gene sequences to support molecular identification of species. In this study, Culicoides were captured using suction traps baited with either carbon dioxide or UV light from transitional habitat between the southern California peninsular mountain ranges and the Colorado desert of southeastern California. Captured midges were initially identified using traditional morphological methods, with species identification subsequently confirmed by sequence analysis of COI and 28S rDNA genes. A total of 19 Culicoides species (or species aggregate) were collected in this study, with genetic sequences published for the first time for 16 of them. The published genetic sequences will support future research on these species, including studies on the ecology and habits of the immature stages of these Culicoides species.