Insect Growth Regulatory and Antifeedant Activity of Aqueous Extract of Glory Lily, Gloriosa superba Linn. against Tobacco Leaf Eating Caterpillar, Spodoptera litura (Fabricius)

Seeds of Glory lily, Gloriosa superba were shade dried and sequentially extracted with different solvents with varying polarity and mixed with water. Water soluble compounds were separated and concentrated under vacuo. Insect growth regulatory activity was assayed through diet incorporation method whereas antifeedant activity was investigated through leaf disc no-choice test method at 24 and 48 h after treatment on third instar larvae of tobacco leaf eating caterpillar, Spodoptera litura. The extract exhibited good antifeedant and growth inhibition activity. After 24 h of treatment antifeedancy was 17.09% at the lowest dose of 10 ppm which increased along with concentration and at highest concentration 54.12% antifeedancy was observed. With increasing exposure time to 48 h, antifeedancy was increased and ranged between 22.69 and 62.35%. Maximum larval and pupal weight reduction and larval mortality (53.33%) were observed at highest dose (700 ppm). IGR activity was found ranging from 26.67 to 60.0% with GI₅₀ 339.23 ppm.