Toxicity of Tridax procumbens leaf extract to dengue vectors Aedes aegypti L. and Ae albopictus Skuse

Insecticides of plant origin are effective in mosquito control owing to its mode of action. In the present study, Tridax procumbens L. ethanolic leaf extract was found to be toxic to the larvae of Aedes aegypti L. and Ae. albopictus Skuse as these caused 100% mortality in Ae. aegypti and 97% mortality in Ae. albopictus after 72 hr, with LC50 values of 288.40, 120.33 and 77.62 mg/ l for Ae. aegypti, and 812.83, 338.84 and 128.83 mg/ l for Ae. albopictus after 24, 48 and 72 hr, respectively. The toxicity of T. procumbens ethanolic leaf extract on larvae of Aedes spp., could be attributed to the presence of phytochemical compounds, viz., betulin, betulinic acid, lupeol (triterpenoid), caryophyllene, isophytol, phytol (terpene), limonene (monoterpene), luteolin (flavonoid), stigmast-5-en-3-ol, 3 (Beta)-, stigmast-5-en-3-ol, oleate, and palmitic acid (sterol) revealed by the gas chromatography-mass spectrometry analysis.