Aedes Aegypti

The Present study was carried out to study the larvicidal efficacy of Aedes aegypti on ethanol, ethyl acetate, petroleum ether and aqueous extracts of Hemidesmus indicus root. The root extract of Hemidesmus indicus with different solvents were tested for their phytochemical constituents. The analysis revealed the presence of Steroids, terpenoids, flavonoids, and carbohydrates in most prominent amount. Larval mortality was observed and recorded after 24, 48, 72 hours exposure periods. All the tested extracts showed moderate to good larvicidal activities. However, the maximum larval mortality was in aqueous extract of Hemidesmus indicus root observed at 72 hours. The LC50 and LC90 values of  Hemidesmus indicus root against the 1st and 2nd , 3rd and 4th instar larvae of Aedes aegypti LC50136.74,LC90 259.16 ppm and LC50 101.09, LC90 198.92 ppm respectively. These results revealed that larvicidal properties of Hemidesmus indicus root and encourages further effort to investigate the bioactive compounds in those extracts that might possess good larvicidal properties when it will be isolated in pure form.

In view of an increasing interest in developing plant derived insecticides as an alternative to chemical insecticides, this study was undertaken to assess the larvicidal potential of  Erythrina indica root and leaf extracts  against two medically important species of mosquito vectors, Aedes aegypti  and Culex quinquefasciatus. Larvicidal activity of methanol, aqueous, ethyl acetate, chloroform and petroleum ether extracts of leaf and root of Erythrina indica were tested against the early fourth instar larvae of A.aegypti and C. quinquefasciatus. Fourth instar larvae of A. aegypti and C. quinquefasciatus were used for assessing the larvicidal activity. A number of 125 larvae were exposed in five replicates of 25 larvae each. Experiments were maintained at 28±1° C, 65±2% relative humidity. The mortality data were subjected to probit analysis to determine the lethal concentrations (LC50 and LC90) to kill 50 and 90 per cent of the treated larvae of the respective species. Among the leaf and root extracts studied for mosquito larvicidal activity, both root and leaf extracts showed the moderate activity. The chloroform extract of the root was moderatively effective against the larvae of C. quinquefasciatus and A. aegypti; the respective values for LC50 and LC90 were 125.55, 118.90 ppm and 375.27, 354.03 ppm. The methanol extract of the leaf was also moderatively effective against the larvae of  C. quinquefasciatus and A. aegypti with respective LC50 and LC90 values 126.60, 126.76 ppm. The finding of the present investigation revealed that the leaf and root extract possesses remarkable larvicidal activity against two medically important vector mosquitoes C.quinquefasciatus and A. aegypti. So this present ecofriendly paradigm proves the efficacy of E.indica as an botanical larvicide.