This study having following objectives such as to study the biology, nutritional indices and mid gut enzymes response with three different botanical insecticides and to determined the nature of insecticidal action was examined by dermal, oral and contact treatments. As an alternative to synthetic ones, plants have been received much attention as a source of pesticidal active secondary metabolites such as phenolics, terpenoids and alkaloids. The effect of water extracts prepared from the leaves of Ipomea carnea (Linn.) Convolvulacea and Pedalium murex (Linn.) Pedaliacea and Adhatoda vasica (Linn.) Acanthacea on the biology, nutritional indices and digestive enzymes of the polyphagous pest Spodoptera litura (Fab.) (Lepidoptera: Noctuidae) was investigated. Increased larval and pupal mortality and drastically decreased larval growth were recorded in the experimental extracts treated caterpillars. Feeding efficiency and feacal excrement were also greatly affected. The digestive enzymes profiles were decreased by the plant extract treatments. Furthermore, they were facilitating the active and easy proliferation of the chemicals for the subsequent pathogens of larvae. Among the three application methods tested, oral treatment caused the highest toxicity, followed by topical application and contact treatment. From this study clearly revealed about the active secondary metabolites were arrested or restricted the ecdyseal process during the moulting period of experimental pest. These results suggest that the three plant species tested may have potential for use as natural bio-pesticides.
S. Sujatha, Baby Joseph and P.S. Sumi, 2010. Medicinal Plants and its Impact of Ecology, Nutritional Effluents and Incentive of Digestive Enzymes on Spodoptera litura (Fabricious). Asian Journal of Agricultural Research, 4: 204-211.