INSECTICIDAL AND ANTIFEEDANT ACTIVITIES OF AQUEOUS LEAF EXTRACTS AGAINST Epilachna vigintioctopunctata (COCCINELLIDAE: COLEOPTERA) UNDER LABORATORY CONDITIONS
B. LOGESHVARARAJ *
Phytoinsecticide Laboratory, Department of Entomology, Annamalai University, Annamalai Nagar – 608 002, Tamil Nadu, India.
S. ARIVUDAINAMBI
Phytoinsecticide Laboratory, Department of Entomology, Annamalai University, Annamalai Nagar – 608 002, Tamil Nadu, India.
*Author to whom correspondence should be addressed.
Abstract
The aqueous leaf extracts of different plant such as Cryptostegia grandiflora, Mansoa alliacea, Allamanda cathartica, Allamanda blanchetti and Xanthium strumarium and leaves of tree species such as Kigelia pinnata, Bauhinia Purpurea, Drypetes roxburghi, Conocarpus lancifolius and Polyalthia longifolia were studied against the grubs of Epilachna vigintioctopunctata at various concentrations under laboratory conditions. Among the plant tested, the maximum insecticidal activity and leaf area protection was noticed in Xanthium strumarium 93.33% and 91.62% at 7% concentration with an estimated LC50 of 1.11% followed by D. roxburghii (80.00% & 85.55%) and C. lancifolius (73.33% and 82.90%) respectively. The minimum per cent mortality was noticed in the treatment, Mansoa alliacea 7% with 40.00% and its antifeedancy were 50.97%. Results revealed that both the antifeedancy and mortality was increased with increasing in concentration of the plant extracts.
Keywords: Aqueous leaf extracts, Epilachna vigintioctopunctata, leaf area protection and natural insecticide