Larvicidal Efficacy of Calotrophis Procera, Annona Squamosa and Tridax Procumbens Leaf Extracts against Vector Mosquitoes (Diptera: Culicidae)

Mosquitoes are the most important single group of insects in terms of public health importance, which transmit a number of diseases, such as Malaria. Filariasis, Dengue, Japanese encephalitis, causing millions of deaths every year. Repeated use of synthetic insecticides for mosquito control has disrupted natural biological control systems and led to resurgences in mosquito populations. It has also resulted in the development of resistance, undesirable effects on non- target organisms and fostered environmental and human health concern. Plants are considered as a rich source of bioactive chemicals and they may be an alternative source of mosquito control agents. In the present study the plant extracts of Calotrophis, Annona and Tridax were screened for their larvicidal activity against mosquito. The mean and percentage mortality was noted at 24, 48,72 and 96 hours of continuous exposure increases. Among the three leaf extracts tested Calotrophis leaf extract is more effective than the others.