2: Arbovirus transmission mechanisms of the Culicoides biting midge

Hematophagous Culicoides spp. biting midges are of great agricultural importance as livestock and wildlife pests. Additionally, they vector a variety of viruses including orbiviruses (bluetongue, epizootic hemorrhagic disease, African horse sickness), orthobunyaviruses (Schmallenberg), and rhabdoviruses (vesicular stomatitis, bovine ephemeral fever). Investigations of the midge-mammal interface for Culicoides sonorensis has provided insight as to why bite transmission of orbiviruses, in particular, is so exquisitely efficient. Most recently, a non-conventional transmission mechanism, venereal transmission, was demonstrated for C. sonorensis which may help explain maintenance of vesicular stomatitis virus in midge populations in the absence of infected animals. Venereal transmission shows the importance of males in transmission dynamics and in virus maintenance in nature. These results highlight how understanding the insect-animal interface can inform bite transmission efficiency and why we need to investigate alternative transmission routes to inform arbovirus epidemiology.