Natural sugar-source associations of <i>Culicoides</i> biting midges (Diptera: Ceratopogonidae) in a Kansas tallgrass prairie

Culicoides Latreille is a diverse genus of approximately 1,300 species of small biting flies found across the globe, containing numerous species of medical and veterinary importance. Many diseases associated with Culicoides have no specific treatment or vaccine, necessitating prevention through vector control. Current surveillance and control methods are limited by a lack of ecological knowledge about most Culicoides species, including phytophagous (sugar-feeding) behavior. The plants fed on by wild Culicoides are largely unknown, as are the driving forces behind selection of specific plants. To determine which plants midges are sugar-feeding on in nature, Culicoides were collected from five sites within a tallgrass prairie ecosystem in northeastern Kansas. Molecular sugar meal analysis was performed to detect plant DNA within field-collected midges. DNA was extracted from a total of 788 biting midge individuals, with 321 (40.7%) of these successfully amplifying and just 78 (9.9%) producing a sequence with a successful host match. Most matches were only identified to the plant family level with high confidence. Culicoides were found to feed on a diverse assemblage of families, including the Amaranthaceae, Cupressaceae, Solanaceae, and Verbenaceae; however, no significant association was found between Culicoides species and plant family. These results suggest that multiple sugar sources, including plant nectar and fruit, are utilized by biting midges under natural conditions. This information is vital for improving ecologically based control strategies, such as attractive toxic sugar baits, that can reduce disease burden on livestock and wildlife.