The Present study was undertaken to evaluate the effect of extraction from Justicia adhatoda leaves on four different solvents activity against the Aedes aegypti and Culex quinquefasciatus. Twenty five Ist to IVth instar larvae of Cx. quinquefasciatus and Ae. aegypti were exposed to various concentrations (60 - 300 ppm) and were assayed in the laboratory for 24 and 48 hours. Petroleum ether and all other solvent extracts such as chloroform, ethyl acetate and methanol leaf extracts of J. adhatoda showed significant results. Cx. quinquefasciatus larvae showed higher mortality than Ae. aegypti larvae among the solvents tested in the present study. The LC50 values of 75.39, 78.19, 84.50, 91.37 ppm were recorded against the Ist to IVth instar larvae of Cx. quinquefasciatus exposed to methanol extracts of J. adhatoda. In the same way LC50 values of 75.36, 79.62, 85.44, 96.06 ppm were recorded against the 1st to 4th instar larvae of Ae. aegypti were exposed to petroleum ether extracts of J. adhatoda respectively. The ovicidal activity was found to be more effective against the eggs of Cx. quinquefasciatus than Ae. aegypti. The adulticidal mortality was highly significant in petroleum ether extract of J. adhatoda leaf showed LC50 values of 73.50, 72.14 ppm and LC90 Values of 142.02, 225.07 in Cx.quinquefasciatus and Ae. aegypti. The petroleum ether extract had strong repellent action against mosquitoes as it provided 100% protection against Ae. aegypti for 210 min followed by Cx. quinquefasciatus 180 min. From the results it can be concluded the leaf extract of J. Adhatoda was an excellent potential for controlling Ae. aegypti and Cx. quinquefasciatus mosquitoes.
