*Corresponding author: +91 9080220148 E-mail: drgovind1979@gmail.com Available online at http://www.bretj.com MOSQUITO LARVICIDAL EFFICACY OF ECLIPTA ALBA (L.) HASSK. AGAINST FILARIASIS VECTOR, CULEX QUINQUEFASCIATUS SAY (DIPTERA: CULICIDAE) Rajamohan Sivakumar and Marimuthu Govindarajan* Division of Vector Biology and Phytochemistry, Department of Zoology, Annamalai University, Annamalainagar- 608 002, Tamilnadu, India ARTICLE INFO ABSTRACT Article History: Received 10 th December, 2012 Received in revised form 20 th , December, 2012 Accepted 5th January, 2013 Published online 31 th January, 2013 Objective: To evaluate the larvicidal activity of hexane, ethyl acetate, benzene, chloroform and methanol extract of Eclipta alba (E. alba) against Culex quinquefasciatus (Cx. quinquefasciatus) . Methods: Twenty five early third instar larvae of Cx. quinquefasciatus were exposed to various concentrations and were assayed in the laboratory by using the protocol of WHO 2005. The larval mortality was observed after 24 h of treatment. Results: All extracts showed moderate larvicidal effects. Maximum larvicidal activity was observed in the methanol extract followed by chloroform, benzene, ethyl acetate and hexane extract. The LC50 and LC 90values of E. alba against early third instar of Cx. quinquefasciatus were 119.83, 134.65, 140.72, 144.11, 157.97 ppm and 234.19, 257.29, 260.60, 274.43, 291.21 ppm, respectively. No mortality was observed in controls. The chi-square values were significant at p < 0.05 level. Conclusions: The results obtained from this study suggest that the leaf extract of E. alba are promising as larvicides against Cx. quinquefasciatus larvae and could be useful in the search for new natural larvicidal compounds. © Copy Right, IJCBB, 2013, Academic Journals. All rights reserved. Key words: Larvicidal activity, Eclipta alba, Plant extract, Culex quinquefasciatus, Filariasis vector INTRODUCTION Mosquitoes are responsible for more diseases than any other group of arthropods. Mosquito-borne diseases, such as malaria, filariasis, dengue/DHF, yellow fever, and Japanese encephalitis, contribute significantly to disease burden, death, poverty, and social debility in tropical countries. Among these diseases, malaria continues to be a major public health problem in most tropical countries. Culex quinquefasciatus (Say.), a vector of lymphatic filariasis, is widely distributed in tropical zones with around 120 million people infected worldwide and 44 million people having common chronic manifestation [1] . Human filariasis is a major public health hazard and remains a challenging socioeconomic problem in many of the tropical countries. Lymphatic filariasis caused by Wuchereria bancrofti and transmitted by mosquito Cx. quinquefasciatus is found to be more endemic in the Indian subcontinent. Different strategies have been developed to reduce the prevalence of mosquito-borne diseases in many regions of the world. Continued applications of organophosphates such as temephos and fenthion and insect growth regulators such as diflubenzuron and methoprene are most common and widely used for mosquito control. But, continued use of synthetic chemical insecticide based measures for vector control has resulted in lower efficacy of such insecticides and appearance of resistance in mosquito population, had undesirable effects on non-target organisms, and produce damages to environment and human health [2] . Synthetic pesticide exposure among human has been linked to immune dysfunction along with various forms of cancer and birth defects [3] . Recently there has been a concerted effort to promote the use of botanical pesticides (as possible alternative to synthetic chemical insecticides), which provide a pest specific, cost effective, easy to use, readily biodegradable and environment friendly method [4] . Therefore, an effort should be made to find alternative insecticides. Plants may be an alternative source of mosquito-control agents because they constitute a rich source of bioactive chemicals, which inhibit growth, development and metamorphosis of insects. Much effort has been focused on phytochemicals as potential source of mosquito-control agents as they are relatively safe, degradable, cost effective and readily available with least International Journal of Current Biochemistry and Biotechnology - Vol. 2, Issue, 1, pp.001-005, January, 2013 INTERNATIONAL JOURNAL OF CURRENT BIOCHEMISTRY AND BIOTECHNOLOGY RESEARCH ARTICLE