The Efficacy of Selected Synthetic Insecticide Formulations against Fall Armyworm Spodoptera frugiperda (JE Smith) Under Laboratory, Semi-Field and Field Conditions

The invasive fall armyworm species, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), was first time reported in Pakistan during March 2019 causing severe damage to maize crop. As a new pest, there is little information available on its susceptibility to insecticides in Pakistan. We evaluated selective synthetic insecticides with different modes of action to control S. frugiperda larvae in the laboratory as well as under semi -field and field conditions. All insecticides performed well in controlling S. frugiperda larvae under laboratory conditions. Though, chlorantraniliprole @ 50 mL/100L (58.0-100%), abamectin @ 400 mL/100L (56.0-100%), lambda-cyhalothrin @ 250 mL/100L (52.0-100%) and chlorpyrifos @ 1000 mL/100L (52.0-98.0%) showed significantly (P < 0.05) higher mortality than other chemicals. Higher concentrations of abamectin (6000 ppm), chlorpyrifos (12000 ppm) and chlorantraniliprole (700 ppm) showed 100% larval mortality at 24 h post -exposure. Lambda-cyhalothrin (3500 ppm) showed 95% larval mortality at 24 h and 100% mortality at 48 h of application. The medium dose rate of abamectin (4000 ppm) and chlorantraniliprole (600 ppm) also showed 100% larval mortality at 48 h of application. In semi -field and field conditions, chlorantraniliprole showed 100% larval mortality at 48 h, while abamectin and chlorpyrifos showed 87-89% and 94-81% larval mortality respectively in semifield to field conditions after 72 h of application. Overall study results demonstrate the effectiveness of chlorantraniliprole, abamectin and chlorpyrifos and these synthetic insecticides should be considered as components of integrated management of S. frugiperda in Pakistan.