evaluation of larvicidal activity of essential oil from leaves of coccinia grandis against three mosquito species

Background: to study the chemical constituents and larvicidal activity of essential oil extracted from the leaves of coccinia grandis against three mosquito species. methods: essential oil was extracted by hydro distillation using clevenger apparatus and was analyzed for chemical constituents by gas chromatography-mass spectrophotometry (gc-ms). larvicidal activity was recorded after 12 and 24h of post-exposure against three mosquito species, anopheles stephensi, aedes aegypti and culex quinquefascia-tus. dead larvae were identified when they failed to move after probing with a needle in the siphon or cervical region. the lc50 and lc90 values for three mosquito larvae were calculated by probit analysis. results: the gc-ms analysis revealed that essential oil contains 23 different constituents. out of these 23 constitu-ents, major constituents identified were n-tetracosane (39.18%), n-eicosane (30.04%), tetratriacotane (2.97%), 7-oc-tadecanal (2.81%), and tricosane (2.31%). essential oil from leaves of coccinia grandis exhibited significant larvi-cidal activity against an. stephensi with lc50 and lc90 values 39.41ppm and 123.24ppm, respectively. this was fol-lowed by ae. aegypti and cx. quinquefasciatus with lc50 and lc90 values of 48.20ppm, 131.84ppm and 52.80ppm, 135.48ppm, respectively after 24h of exposure. conclusion: the results could be useful in developing a cost effective, ecofriendly, region specific and practical strategy for the control of mosquito vectors.