Abstract
Mosquitoes act as a vector for most of the life threatening diseases like malaria, yellow fever, dengue fever, chikungunya fever, filariasis, encephalitis, west nile virus infection, etc. The continuous application of synthetic insecticides causes development of resistance in vector species, biological magnification of toxic substances leads to an adverse effects on environment and non target organisms. In view of the recently increased interest in developing plant origin insecticides as an alternative to chemical insecticide, this study was undertaken to assess the larvicidal and ovicidal potential of the crude aqueous and methanol solvent extracts of leaves and seeds of the medicinal plant Pongamia pinnata against the mosquito vectors Culex quiquafaciatus, Anopheles stephensi and Aedes aegypti (Diptera: culicidae).Larvicidal activity of Pongamia pinnata leaf aqueous extract (PPLAE), leaf methanol extract (PPLME); seed aqueous (PPSAE) and seeds methanol extracts(PPSME) was studied in the range of 50-400ppm against fourth instar larvae of Culux quinquefasciatus , An. stephensi and Ae. aegypti in the laboratory. Larvae were exposed to varying concentrations of crude extracts (PPLAE, PPLME, PPSAE and PPSME). Considerable mortality was evident after the treatment of P. pinnata for all three important vector mosquitoes. The ovicidal activity was determined against Cu quinquefaciatus, Ae. aegypti and An. stephensi to various concentrations of leaf and seed methanol extracts (PPLME and PPSME) ranging from 100 to 900 ppm under laboratory conditions. Mean percent hatchability of the eggs were observed after 48h post treatment.All leaf (PPLAE, PPLME) and seed extracts (PPSAE, PPSME) showed moderate larvicidal and ovicidal effects; however, methanol extracts of leaf (PPSME) of P. pinnata against the larvae of Culux quinquefasciatus , Ae. aegypti and An. stephensi LC50 and LC90values of 153.09, 288.24 ppm; 140.656, 277.74 ppm; and 106.27, 231.99 ppm, respectively. P. Pinnate methanol extract of seed (PPSME) LC50 and LC90values of 140.656, 277.74 ppm; 123.572, 228.236ppm and 100.272-231.996 ppm, respectively against the three vector mosquito larvae ovicidal efficacy of P. Pinnata the percent hatchability was inversely proportional to the concentration of extract and directly proportional to the eggs. The methanol leaf extract of P. pinnata against An. stephensi Ae. aegypti and,Culux quinquefasciatus exerted 100% mortality (zero hatchability) at 500, 600 and 700 ppm, respectively, With PPSME 100% mortality at 600, 700 and 700 ppm, respectively. Control eggs showed above 98-100% hatchability. Among the extracts tested, the highest ovicidal activity was observed in the PPLME. Compared to leaf extracts (PPLME) seed extracts (PPSME) have low potency against the three vector mosquitoes.Our data suggest that the crude leaf and seed aqueous (PPLAE, PPSAE) and methanol solvent extracts (PPLME, PPSME)of P. pinnata have the potential to be used as an eco-friendly approach for the control of mosquitoes.

15030212 Larval and Ovicidal effects of Pongamia pinnata pdf