Copulation and Egg-laying Behavior of the Tea Leafroller, Caloptilia theivora（Lepidoptera: Gracillariidae）in the Laboratory

Abstract

We conducted a laboratory investigation on the growth, copulation and egg-laying behavior of the tea leafroller Caloptilia theivora（Walsingham）, a serious pest of tea plants in Japan. The aim of the study was to obtain basic information that can be used to control the tea leafroller. When reared at 24°C, adult males emerged earlier than adult females by 1.5 days. On the day of emergence, adult females copulated, but males did not. These observations suggest that males have adopted a mating strategy in which they emerge earlier than females and become sexually mature before females emerge. Next, we investigated the influence of copulation frequency on the adult longevity and number of eggs laid by females. Males and females kept virgin for their entire life lived significantly longer than those allowed to mate. Males and females copulated repeatedly during their entire life when allowed to mate freely; females exposed to males for life laid more eggs than those exposed to a male for one day. Females laid eggs between 22:00 and 24:00. These findings may be used to develop a management strategy against the tea leafroller using mating disruption with synthetic sex pheromones and disturbance of oviposition by lighting.