BIOLOGICAL AND BEHVIOURAL STUDIES ON CERTAIN SCARABAEID BEETLES OF AGRICULTURAL IMPORTANCE IN EGYPT

Abstract

The present work has cf,me as a continuity of a previous study on the peach cockchafer Pachnoda fasciata (Kamel 1988). The present study is concerned With some behavioural studies on two scarabaeids of economic importance in Egypt, i-e the hairy rose beetle Tropinota squal ida Scop. and Pachnoda fasciata F.. Results of laboratory and field studies demonstrated that there are some similarities between the behaviour of the two species. Each of the two species has one generation a year (univoltine insect). The adults of both of them are diurnal, becoming active during the day, especially in sunny weather and mating takes place on branches of the favourable fruits and ornamental trees. Yet, no cop,lwas observed during the flight. Females of T. squal ida and P. fasciata illy their eggs in the soil, where the hatched larvae construct their tunnels. Females of T. squa Z ida showed different degrees of preference to different soil mixtures as oviposition media; it was found that a soil mixture composed of clay, cattle dung, peatmoss and sand in equal proportio ,.ivas the most attractive one where more eggs were laid by the female. In addition, females of T.