Novel Insight into Culicoides (Diptera: Ceratopogonidae) Host Preferences and the First Evidence of Avian Haemosporidian Parasites in Biting Midges in Slovakia

<i>Culicoides</i> biting midges (Diptera: Ceratopogonidae) are important vectors of avian haemosporidian parasites. Understanding their host preferences is crucial for elucidating transmission routes of vector-borne pathogens. In Slovakia, such knowledge is limited, particularly in forested wetlands. This study aimed to identify <i>Culicoides</i> species, their host preferences, and haemosporidian parasites in a wetland ecosystem at the Bird Ringing Station in Drienovec. Midges were collected in 2022 using UV light traps at two sites. In total, 2344 <i>Culicoides</i> individuals of 19 species were collected. Host blood was identified and DNA subsequently extracted from 36 engorged females, revealing feeding on three mammal and five bird species. The most frequently identified host was roe deer (<i>Capreolus capreolus</i>), predominantly fed upon by <i>Culicoides obsoletus</i> (Meigen 1818). Notably, avian haemosporidian DNA was detected for the first time in Slovakia in three <i>Culicoides</i> females. In two <i>Culicoides alazanicus</i> Dzhafarov 1961 individuals, DNA of <i>Haemoproteus asymmetricus</i> (TUPHI01) and <i>Plasmodium matutinum</i> (LINN1) was confirmed, both associated with avian blood from <i>Turdus</i> sp. One <i>Culicoides festivipennis</i> Kieffer 1914 female carried <i>Haemoproteus tartakovskyi</i> (HAWF1) and fed on <i>Coccothraustes coccothraustes</i>. These findings highlight the potential role of local <i>Culicoides</i> species in transmitting avian pathogens and underscore the importance of monitoring their ecology.