2010 Volume 54 Issue 3 Pages 107-113
To clarify the timing of the appearance of overwintered and diapausing adults of the rice bug, Leptocorisa chinensis, under natural condition, we adopted two criteria, the developmental stages of gonads and the number of endocuticle layers in the cuticle of the hind-leg femur. Development of gonads after emergence was promoted in adults reared under a long-day photoperiodic condition, but suppressed under a short-day condition. The deposition rate of endocuticle layers was not influenced by the photoperiod but depended on age. These criteria were applied to estimate the annual number of generations of this species in Yamatsuri, Fukushima Prefecture, in 2006. According to these criteria, adults caught in early August, late August and early September were identified as an overwintered, newly-emerged and diapausing individuals, respectively. These data show that L. chinensis has mainly a univoltine life cycle in this region.
