DefinePK

Abstract

Abstract | Solanum nigrum L., commonly known as Makoi or Black Nightshade, is a widely cultivated fruit vegetable crop valued for its high nutritional content. However, its production is significantly threatened by the cotton leafworm (Spodoptera littoralis). This highly destructive pest causes severe economic losses and compromises crop quality due to its aggressive feeding behavior. Biopesticides have recently gained attention as sustainable alternatives to conventional insecticides for managing S. littoralis infestations. This study evaluated the efficacy of three commercial bioinsecticides applied at their recommended concentrations against 2nd instar larvae of S. littoralis under semi-field conditions over two growing seasons. Larval mortality was assessed three days post-treatment, and all tested bioinsecticides demonstrated significant effectiveness. Among them, emamectin benzoate consistently exhibited the highest mortality rate across both seasons. Additionally, the tested bioinsecticides remained effective for up to 10 days after application. Treatment with LC50 concentrations of these bioinsecticides resulted in significant alterations in soluble protein, carbohydrate, and lipid levels, as well as the activity of specific carbohydrate-hydrolyzing enzymes. These findings highlight the potential of bioinsecticides as effective and eco-friendly alternatives to synthetic pesticides, offering both targeted pathogenic effects on insect pests and safety for non-target organisms.