Efficacy of Some Insecticides on Different Larval Instars of Spodoptera litura (Fab.) under Laboratory Condition

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.