A study on dominant Culicoides (Diptera: Ceratopogonidae) species with special reference to sex, parity and voltinism and their possible implication on bluetongue transmission in Bidar, Karnataka

Bimonthly collection of Culicoides midges near the cattle shed in Bidar (Karnataka, India) at fortnightly intervals using down draught light trap (220 Volts) during the period from June 2004 to July 2005 yielded 27 collections. A total of 7 species of Culicoides were identified. Culicoides imicola (43.26%) and C. oxystoma (48.80%) appeared consistently with higher abundance hence, were considered as dominant species. There were a total of 8 peaks of abundances of nulliparous C. imicola between June 2004 and May 2005 and for C. oxystoma there were 7 peaks between June 2004 and June 2005. Consistent higher parous rate was observed in both the species. The increase in male to female ratios (number of males per female) of C. imicola and C. oxystoma during April to May indicates the initiation of mating activity. The presence of nulliparous females in substantial numbers in both the species throughout the study period indicates that breeding takes place continuously. The consistent higher parous rate of both the species throughout the study period indicated that both species have potentiality to act as vectors for diseases such as Bluetongue.