Ecology, Environment and Conservation Paper

LARVICIDAL ACTIVITY OF STRYCHNOS NUXVOMICA AGAINST ANOPHELES STEPHENSI

P.A. Sajudeen, Jiji Thomas, K. Jayachandran, P.M. Koshy and Mohammed Ashiq

Abstract

Mosquitoes serve as vectors of several diseases and the past few decades have witnessed the emergence of mosquitoborne diseases globally. Rapid urbanization, habitat fragmentation and climate change promotes breeding grounds for mosquito and related health risks. High morbidity and mortality are observed due to mosquitoborne diseases. The emergence of insecticide resistance aggravated the problem which initiated search for alternative control measures with less health and environmental hazards. The present study is to assess the mosquito larvicidal activity of indigenous plant Strychnos nuxvomica Linn. Seed extracts were used to determine the mortality rate of fourth instar larvae of Anopheles stephensi. In definite screening the fourth instar larvae were exposed to different concentrations such as 500, 200, 100, 50, 25, 12.5 and 6.5 ppm, and the rate of mortality was studied. The LC 50 values have been determined by probit analysis. The acetone and petroleum ether seed extracts of Strychnos nuxvomica Linn are effective as larvicides at lowest concentrations. The results indicate that plant based pesticides are promising to control mosquito menace.