Number of annual generations of Cletus punctiger (Heteroptera: Coreidae) in Shiga Prefecture

Abstract

The coreid bug, Cletus punctiger, is widely distributed in Japan. This bug is a pest that sucks developing rice grains and causes pecky rice. Developmental zeros and effective accumulative temperatures of the bug were calculated from its developmental periods at different constant temperatures. The developmental zeros were 14.9°C in the egg stage, 13.8°C and 13.7°C in the egg and nymphal stages of female and male, respectively, and 16.6°C in the preoviposition period. The effective accumulative temperatures were 82.6 day-degrees in the egg stage, 400 day-degrees in the egg and nymphal stages of female and male, and 200 day-degrees in the preoviposition period. On the basis of these data, the number of annual generations of C. punctiger in Shiga Prefecture was estimated to be two.