LARVICIDAL ACTION OF FOUR INDIGENOUS PLANT EXTRACTS AGAINST DENGUE VECTOR AEDES AEGYPTI

The world flora possesses a variety of plants having potential insecticidal activities. This quality increased the demand of plant extracts. The present study was conducted to evaluate four plant extracts against 3rd instar larvae of Aedes aegypti. The mortality counts (LC_50 ) were made after 24, 48, 72 and 96 hrs whereas time mortality (LT ) was recorded at different 50 concentration (20, 10, 5, 2.5, 1.25, 0.75 and 0.37 %). Results indicate that the extract from Citrus sinensis was more effective having lowest LC_50 (%) = 71.83, 7.28, 2.43 and 0.84, at 24, 48, 72 and 96 hrs, respectively) followed by Azadirachta indica, Eucalyptus cameldulensis and Datura stramonium. However, lethal time (LT_50 ) on larvae of Aedes aegypti showed the same order of potency as mentioned above. Generally speaking, the doses are directly proportional to the time interval. Our study suggested that citrus extracts are more potent and effective in managing the population of dengue vector; Aedes aegypti. Further, research needed to identify, the probable role of extract as ovicide, anti-feedant, repellence and adulticidal agent.