Measuring Culicoides sonorensis development in common substrates found in white-tailed deer-breeding facilities

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. Work conducted aimed to identify common areas of Culicoides sonorensis development in a deer facility. Samples of white-tailed deer manure, deer feed, the USDA rearing medium, and deionized water were used as substrate foundations. Substrates were inoculated with 50 C. sonorensis eggs, incubated at 28°C, 65% RH and 13:11 [L:D], and insect development was monitored until they reached the adult stage. Results demonstrated immature C. sonorensis completed development in a feed-based substrate more successfully than the rearing medium and deionized water. Initial measurements of pH and NH₄ were taken from the substrates and dissolved oxygen content was monitored over the 30 day experiment. There was a significant difference in the pH, NH₄, and dissolved oxygen concentrations between the tested growth substrates. This information will be utilized to design integrated pest management (IPM) recommendations for Texas white-tailed deer producers. Results from this C. sonorensis development study will soon prove to be an asset to entomological researchers and deer producers.