Monitoring of Culicoides spp. as disease vectors in white-tailed deer (Odocoileus virginianus) production facilities

The biting midge, Culicoides spp. (Diptera: Ceratopogonidae), is an important ectoparasite disturbing white-tailed deer (Odocoileus virginianus) populations in Texas. Biting midges are vectors of disease agents causing epizootic hemorrhagic disease (EHD) and bluetongue (BTV).  These diseases are easily recognized and feared by white-tailed deer producers, yet there is limited literature on biting midge management. Sampling of Culicoides spp. on six Texas deer ranches located in different biomes in Texas began in 2013 and will continue throughout 2014.  The sampled Culicoides spp. have been identified to the species level and submitted to the Texas Veterinary Medical Diagnostics Laboratory for viral isolation. Successful isolation of EHD – 1 and 2, and BTV, has shown that several species of Culicoides sampled in the southern regions of Texas are possible threats to surrounding white-tailed deer. The BTV serotype sampled is currently in the identification process. After monitoring arthropods for over a year on different deer production ranches, it is apparent that insects are commonly associated with deer held in intense management units. Management of these insects, particularly the biting flies, will take an integrated approach. Several deer management facilities in Texas have incorporated pesticide misting systems, which automatically apply pesticides several times a day. The impacts of these systems have not been adequately evaluated to determine if they control insect populations, or reduce incidences of EHD or BTV diseases in captive cervid operations. Results from this statewide insect trapping and sampling will soon prove to be an asset to entomological researchers and deer producers.