Effects of egg age in Sesamia cretica (Lepidoptera: Noctuidae) on parasitism, development and reproduction of Telenomus busseolae (Hymenoptera: Platygastridae)

The sugarcane stem borer, Sesamia cretica Lederer, is one of the most economically important pests of sugarcane in Khuzestan province, southwest Iran. The egg parasitoid Telenomus busseolae Gahan significantly affect S. cretica population in the field. Host age is an important factor of host acceptance and suitability for egg parasitoids. We examined the ability of T. busseolae to parasitize and develop in S. cretica eggs of different ages. In a no choice laboratory experiment, we measured the effect of host age (۱۲, ۳۶, or ۶۰h old) on parasitism rate and offspring fitness characteristics such as survival, development time, sex ratio, size, and progeny longevity and fecundity. Results revealed that the suitability of host eggs decreased as host age increased. Exposure of parasitoids to ۱۲h old eggs resulted in higher percentage parasitism, higher acceptance, higher survival and larger body size of parasitoid progeny. Progeny that emerged from ۱۲h old eggs had also higher longevity and fecundity than those emerged from other host ages tested.