Development of a Paddy-Dwelling Chironomid, Chironomus kiiensis (Diptera, Chironomidae) under Different Temperatures

Chironomus kiiensis, a dominant paddy-dwelling chironomid species, was reared from eggs under different temperature regimes to examine its development or survival in view of the high summer temperatures of paddy water in western Japan. Figures of wing length, number of ovarian eggs and percentage emergence changed significantly at 25℃, 30℃ and 37℃, respectively. The developmental period is shorter at 30-37℃ than below 30℃ or above 37℃. Highest temperature allowing development of the species seems to be 38℃ or 39℃. In western Japan, this species may temporarily encounter difficulty in developing normally in summer, but the damage is not necessarily fatal to the population.