Entomological survey of <i>Culicoides</i> Species (Diptera: Ceratopogonidae), Bluetongue Virus Vector in a Goat Breeding Farm of West Bengal, India

The Culicoides-borne bluetongue virus (BTV) significantly impacts national economic turnover by affecting livestock animals. Higher seropositivity and direct isolation of multiple BTV serotypes have been detected in goat populations residing in several states, indicating their probable role as amplifying or reservoir hosts for BTV. Unfortunately, the scarcity of data on vector surveillance of goat farms in India is a pressing issue that needs to be addressed. Study was conducted to enumerate the diversity, seasonal abundance, and temporal activities of the Culicoides species (Diptera: Ceratopogonidae) associated with the Black Bengal goat. UV-LED light traps as well as sticky trap were simultaneously operated inside the goat seed farm for each 12 month period in the year of 2022. A microclimatic device was installed inside the pen to log real-time temperature, humidity, and lux inside the shed to compare the data with weather station data. A total of 2,960 adult individuals (male=42.12%; female=57.87%) were trapped, with a significant percentage (71.95%) captured during the rainy season. Results showed the presence of six potential vector species, with Culicoides oxystoma Kieffer, 1910 (87.08%) being the dominant one followed by Culicoides peregrinus Kieffer, 1910, Culicoides fulvus Sen and Das Gupta 1959, Culicoides actoni Smith 1929, Culicoides anophelis Edwards, 1922, Culicoides innoxius Sen and Das Gupta,1959. Light traps primarily caught female individuals (69.48%), whereas sticky traps predominantly captured adult males (75.32%). Sticky traps may help assess male populations and infer probable breeding habits. A minimum and maximum microclimatic temperature difference of 2-4 °C was observed between inside of the shed and weather station data. This data is significant as it provides insights into the microclimatic conditions that may influence the abundance and activity of Culicoides species. The relatively high prevalence and presence of multiple potential vector species, particularly during the rainy season, highlight the relevance and applicability of continuous surveillance and appropriate preventative measures to minimize the risk of exposure to BTV vectors.