Abstract

MOSQUITO LARVICIDAL EFFICACY OF LEAF EXTRACTS OF TURNERA SUBULATA AND GREEN SYNTHESIZED SILVER NANOPARTICLES ON CULEX QUINQUEFASCIATUS

Bavani Govindarajulu*, Gobika G., Karthikeyan J., Abirami T. and Kavitha V.

Abstract

Mosquitoes are responsible for the transmission of many vector borne diseases. Lymphatic filariasis, a diseases caused by the infection of Wuchereria bancrafti was transmitted by the Culex quinquefasicatus and around 100 million people are affected by these around the world. In the present study the larvicidal activity of the various plant extracts of Turnera subulata was estimated with concentrations varying from 50ppm to 250 ppm. The efficacy of plant mediated synthesized silver nanoparticles were tested against early 4th instar larvae of Culex quinquefasciatus. The observation of the results reveals the maximum larvicidal potential of 95.60 percentage with chloroform leaf extract with LC50 and LC90 values of 51.021ppm and 235.417ppm respectively. However, the larvicidal efficacy of the silver nanoparticles was maximum when compared to the extracts where a percentage mortality of 98% was recorded with 5ppm concentration with the LC50 value of 45.499 ppm after 72 hours of experiment period. The results suggests that the bioactive compounds such as alkaloids and terpenoids were responsible for the larvicidal activity, while the bioactive compounds capped with the silver nanoparticles increased the potentiality of these particles against 4th instar larvae of Culex quinquefasciatus. To conclude, the application of green synthesized silver nanoparticles and the isolation and characterization of the bioactive compound from the chloroform leaf extract of Turnera subulata will pave way for the control of disease causing mosquitoes.

Keywords: Culex quinquefasciatus, Turnera subulata, larvicidal, silver nanoparticles, phytochemicals.