Monitoring and management of Culicoides spp. (Diptera: Ceratopogonidae) in white-tailed deer (Odocoileus virginianus) production facilities in Texas, USA

Biting midges, Culicoides spp. (Diptera: Ceratopogonidae), are important ectoparasites which disturb white-tailed deer (Odocoileus virginianus) populations in Texas. Biting midges are vectors of disease agents causing epizootic hemorrhagic disease (EHD) and bluetongue (BT). These diseases are easily recognized and feared by white-tailed deer producers, yet there is limited literature on biting midge management. The objectives of this dissertation study aimed to identify entomological problems faced by white-tailed deer producers in Texas. Four objectives were designed to address the questions of which insects were present in the deer-breeding pens, insect abundance, specifically presence of which Culicoides spp., distribution of BTV and EHDV, identification of the common organic materials in deer-breeding facilities used by Culicoides spp. for development, and integrated pest management recommendations specifically designed for Texas deer breeders. Twenty-four ranches across Texas participated in a two-year sampling study of Ceratopogonidae near deer-breeding pens. Results showed that filth flies were the most abundant group measured throughout the experiment and up to eight ceratopogonids were sampled at a time for a specific location. The second objective was to identify specific Culicoides species present in East Texas. Five Culicoides species were identified from seven ranches. Three species tested positive for EHDV or BTV using a real- time PCR procedure. Results from this study will be used to target insect control to specific Culicoides spp. in Texas white-tailed deer-breeding facilities. Work conducted also aimed to identify common areas of Culicoides sonorensis development in a deer facility. Samples of manure, deer feed, the USDA rearing medium and deionized water were used as a substrate foundation and C. sonorensis development. Results demonstrated immature C. sonorensis more successfully completed development in a feed-based substrate than the rearing medium and deionized water. This information was utilized to design integrated pest management (IPM) recommendations for Texas white-tailed deer producers. Management of these insects, particularly the biting flies, will take an integrated approach. Biological, chemical, physical, and cultural recommendations are commonly used for pest control in production systems. There has previously not been an IPM program designed for white-tailed deer producers. Results from this collection of Culicoides spp. studies will soon prove to be an asset to entomological researchers and deer producers.