Host-seeking and exophilic-endophilic activities of Culicoides spp. (Diptera: Ceratopogonidae) with notes on two trapping methods.

Host-seeking behavior of Culicoides species was examined from 2018 to 2019 in West Bengal, India, which elucidated diel activity, feeding success, attack rate, biting rate, and preferential landing of adult Culicoides on the cattle. A comparative assessment was done between the light trap and the aspirator. The host-seeking experiment involved a substantial timeframe of 297 h of catch collections over 27 nights. The number of adult Culicoides captured in the light trap was 1.3 times higher than the aspirator collections. The species in light trap catch were Culicoides oxystoma Kieffer Culicoides peregrinus Kieffer, and Culicoides fulvus Sen and Das Gupta (Diptera: Ceratopogonidae). However, only C. oxystoma and C. peregrinus were collected using the aspirator. The findings related to feeding success, attack rate, and biting rate carried significant implications for the vectorial potential of C. oxystoma and C. peregrinus. The light trap data suggest that Culicoides species displayed crepuscular behavior, while the aspirator collections peaked 1 h before sunrise, between 04:00 and 05:00 h, and gradually declined. A separate study evaluated the exophily and endophily of Culicoides in 2016 at Memari in West Bengal. To delve into the indoor-outdoor activity, 264 trap collections were made in 4 combinations: Light trap operated in the presence and absence of cattle, placed outdoors and indoors. The study revealed that the outdoor prevalence of midges was 14 times higher than the indoor. There was a 6-time increase in the prevalence of adult Culicoides in the presence of cattle, indicating a preference for outdoor locations for feeding.