Mosquitocidal activity of indigenenous plants of Western Ghats, Achras sapota Linn. (Sapotaceae) and Cassia auriculata L. (Fabaceae) against a common malarial vector, Anopheles stephensi Liston (Culicidae: Diptera)

Abstract

Objective: To evaluate the mosquito larvicidal, ovicidal, pupicidal and repellent activities of hexane, diethyl ether, dichloromethane, acetone and methanol extracts of Indian medicinal plants, Achras sapota (A. sapota) and Cassia auriculata (C. auriculata) at different concentrations against Anopheles stephensi (An. stephensi), a malarial vector. Methods: Twenty five early third instar larvae of An. stephensi were exposed to various concentrations (30-210 mg/L) of plants extracts and were assayed in the laboratory by using the protocol of WHO 2005; then after 24 h LC50 values of the A. sapota and C. auriculata leaf extract was determined by probit analysis. The ovicidal activity was tested with the extracts ranging from 50350 mg/L. The pupicidal activity was recorded after 24 h of exposure to the extract. The repellent efficacy was determined against mosquito species at two different concentrations 1.5 and 3.0 mg/ cm 2 under laboratory conditions. Results: Among the five different extracts tested against the An. stephensi, methanol extract of A. sapota proved to be an more effective solvent extract in almost all the parameters studied than C. auriculata. Conclusions: It is inferred that the leaf extract of A. sapota and C. auriculata could be used in vector control programme.