Bioefficacy of Abamectin and Emamectin Benzoate against Spodoptera litura (Fab.)

The LC₅₀ values of abamectin and emamectin benzoate against third and final instar larvae of Spodoptera litura Fab. by leaf disc ingestion method were 13.9 and 65.7 μg mL⁻¹ and 0.5 and 1.1 μg mL⁻¹ compared to 296.8 and 5014.2 μg mL⁻¹, and 19.1 and 359.5 μg mL⁻¹ in topical method, respectively. The LC₅₀ value of these compounds against eggs and pupae of S. litura by dip method were 2.0, 69.5, 0.1 and 5.3 μg mL⁻¹, respectively. Whereas the LD₅₀ values of abamectin and emamectin benzoate against the third instar larvae by topical method were 0.0096, 0.0111, and 0 0003, 0.0008 μg mg⁻¹ larval weight respectively The LT₅₀ values of abamectin against third and final lnstar larvae of S. litura by leaf disc ingestion method ranged between 52.8 and 22.4 h (20 to 150 μg mL⁻¹), whereas in topical method it ranged between 74.0 and 22.5 h (400 to 6500 μg mL⁻¹). The LT₅₀ value of emamectin bbezoate aaainst the third and final instar larvae by leaf disc ingestion method ranged between 79.9 and 23.7 h (0.6 to 2.4 μg mL⁻¹), whereas in topical method, it ranged between 72.4 and 24.3 h (25 to 850 μg mL⁻¹).