Phenology Study of Parasitoid Telenomus busseola Gahan (Hym., Scelionidae) based on egg population of sugar cane stem borer's egg Sesamia nonagrioides Lefebvre (Lep., Noctuidae) and comparison of parasitism percent by recruitment and common method

Sugar cane stem borers are the most important pest of this crop in the world and Iran. Parasitism percent of the stem borer Sesamia nonagrioides Lefebvre by the wasp Telenomus busseolae Gahan was studied in Shooshtar, south of Iran in 2005-2006. The study was conducted in a Ratoon field in the first year and in a Plant field in the second year, both cultivated with variety of CP48 103. Numbers of parasitized and non-parasitized eggs were recorded weekly and percent parasitism was calculated by two methods of common and recruitment methods. Results showed a similar trend of the host and parasitoid populations in Ratoon field. However, the population of host’s eggs was in high in Plant field in the beginning of September, while the number of parasitized eggs was low. In addition, the parasitoid showed six period of activities during the agronomic year. According to these results the two methods were different, in percent parasitism eraluation. Meanwhile these results showed that recruitment was more reliable than the common method. The study also indicated that the parasitoid has an important effect on population dynamics of sugar cane stem bore in this area.