ROLE OF LEAF EXTRACTS OF Annona reticulata Linn. PLANT AS LARVICIDAL AGENT AGAINST JAPANESE ENCEPHALITIS VECTOR, Culex vishnui

Mosquitoes are the vector of many diseases. Japanese Encephalitis virus which causes Japanese encephalopathy is transmitted by Culex vishnui (Cx. vishnui) group mosquitoes. Japanese Encephalitis is prevalent in Eastern and Southern Asia. Plant based insecticides are safe to use for controlling mosquito population. The present research-work assessed the role of larvicidal efficacy of leaf extracts of Annona reticulata L. (A. reticulata) against Cx. vishnui. 2-10 ppm range of dosages of crude and 10-25 ppm range of dosages of petroleum ether leaf extracts of A. reticulata plant were used to examine the larvicidal efficacy against 1st – 4th instars larvae of Cx. vishnui. Per cent mortalities were noted for a period of 24, 48 and 72 hrs of post exposure cumulatively. Data of percent mortalities versus dosages were subjected to Probit and Regression analyses and respective LC50 values, LC90 values, Regression equations and R2 (co-efficient of determination) values were calculated and noted. All instars larvae showed 100% mortality with crude leaf extract of the plant at very low doses. 1st instar larvae are most susceptible to petroleum ether leaf extract. Control treatments did not exhibit any mortality on the tested larvae. Tested non-target organisms were not susceptible to crude and petroleum ether leaf extract. Statistical significance was done through ANOVA analyses. Crude and petroleum ether leaf extracts of A. reticulata plant can be used effectively to control Cx. vishnui mosquito species. Non target organisms did not response to crude and petroleum ether leaf extracts respectively, so their uses will be also eco-friendly for the environment.