Efficacy of Some Insecticides on Different Larval Instars of Spodoptera litura (Fab.) under Laboratory Condition
Muhammad Abu Talha
Department of Entomology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, Bangladesh.
Md. Mizanur Rahman
Department of Entomology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, Bangladesh.
Mohammed Sakhawat Hossain
Department of Entomology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, Bangladesh.
Md. Razzab Ali
Department of Entomology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, Bangladesh.
Masud Reza
Faridpur Sugar Mills Ltd., Faridpur, Bangladesh.
Md. Shahidul Islam Khan
Department of Entomology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, Bangladesh.
Md. Emam Hossain *
Department of Entomology, Faculty of Agriculture, Sher-e-Bangla Agricultural University, Sher-e-Bangla Nagar, Dhaka, Bangladesh.
*Author to whom correspondence should be addressed.
Abstract
Spodoptera litura (Fab.) is a severe agricultural insect pest causing significant damage across a wide range of crops. This research aimed to determine the effect of some insecticides on different larval stages of this pest using several insecticides dosages at three distinct schedules (8h, 16h, and 24h) during the third larval stage. The mortality rate peaked after 24 hours, while the lowest rate was documented to have occurred 8 hours following insecticide treatment. After 8 hours, the highest death rate (15%) was recorded by spraying Virtako 40WG solution (thiamethoxam + chlorantraniliprole) at 0.2 g/liter of water, followed by 12.5% in Nitro 505EC solution (cypermethrin + chlorpyrifos) treated larvae at 2.0 ml/liter of water. After 24 hours of insecticide treatment, spraying with Nitro 505 EC solution resulted in the greatest larval death percentage (92.50%) with a 428.57% increase above control, followed by Virtako 40 WG solution (90.00% and 414.28%, respectively). Conclusively, Virtako 40WG and Nitro 505EC effectively controlled the immature stage of Spodoptera litura in lab conditions, which may be further trialed to validate this result.
Keywords: Spodoptera litura, larvae, thiamethoxam, chlorantraniliprole, cypermethrin, chlorpyrifos