First description of the pupa of the biting midge Culicoides sonorensis (Diptera: Ceratopogonidae), vector of Bluetongue

Species of Culicoides (Diptera: Ceratopogonidae) are of enormous economic importance as vectors of many disease pathogens affecting livestock worldwide. Despite their importance, there are still huge taxonomic gaps in our understanding of this genus. Of the 1,343 known species, only 13% and 17% are known as larvae and pupae, respectively. Our study describes, for the first time, the pupa of C. sonorensis. This species is responsible for the transmission the Bluetongue virus (BTV) in North America, which causes the loss of an estimated $3 billion USD a year worldwide. The pupa of Culicoides sonorensis can now be recognized in the field, which will aid in future biological, control, and systematic studies. Our study also provides the first complete Scanning Electron Microscope (SEM) study of any species in the genus. An SEM and a compound microscope were used to obtain digital images of the defining characteristics of this species, and illustrations were used to supplement difficult to interpret structures. This description can be used as a format for further descriptions of pupae of Culicoides and will enhance our understanding of the breeding sites of this interesting and economically important species.