Title : Control of sugarcane stem borrers, Sesamia spp, focus on mass rearing of its parasitoid wasp, Telenomus busseolae (Hym.: Platygasteridae)
Abstract:
Sugarcane stem borers, Sesamia spp., are the most important pests of sugarcane, causing death of the central bud during tillering, damage to internodes during stem formation, and reduction of sugar storage and sugar quality during ripening. If not controlled, they can cause significant quantitative and qualitative damage to sugarcane yield annually. The parasitoid wasp, Telenomus busseolae is the most important natural enemy of these pests in sugarcane fields in Khuzestan province, Southern of Iran. The aims of the present study are to evaluate the damage caused by sugarcane stem borers during the years 2020 to 2023, to control sugarcane stem borers with emphasis on mass production of the parasitoid wasp, T. busseolae, and to determine the biological characteristics of wild and reared populations of this parasitoid on sugarcane stem borers eggs. The results showed that the highest amount of physical control against stem borers was in 2022 (about 1.78 times more than in 2021). In addition, biological control increased about 3.08 times from 2020 to 2022, which in turn significantly reduced the infection of sugarcane stem borers. So that the infestation rate of internodes and the percentage of dead heart (infestation of the cane head) in 2022 were 9.48 and 28.68 percent, respectively, which decreased by 2.73 and 17.36 percent, respectively, in 2023, which was due to physical and biological control. Also, the findings confirm that the percentage of parasitism and emergence rate in wild and reared populations did not have a statistically significant difference, while the sex ratio in the two studied populations was statistically significant in both 2022 and 2023. Therefore, the findings of this study confirm that the parasitoid wasp T. busseolae is a potential biocontrol agent that is native to sugarcane fields in Khuzestan Province, and its mass production can be an effective step towards controlling sugarcane stem borers insect pests.