501 Over two billion people, primarily in tropical countries are at risk from mosquito-borne diseases, like dengue, chickungunya, hemorrhagic fever, encephalitis, malaria and filariasis, which remain a major source of illness and death worldwide, particularly in tropical and subtropical climates (Becker, 2003). The mosquito Culex quinquefasciatus (Say) (Family: Culicidae) is the potential vector of Bancroftian filariasis throughout the world including India. The usage of synthetic insecticides against mosquitoes cause environmental pollution, residual effects and resistance (Chung et al., 2004; Pitasawat et al., 2007). Now a days, botanicals have been used as larvicides, growth regulators and repellents against Cx. quinquefasciatus. They include Azadirachta indica (A. Juss.) (Mandal, 2011), Calotropis procera (Aiton) (Singh et al., 2005), Centella asiatica Brahmi. (Rajkumar and Jebanesan, 2005), Lepidagathis alopecuroides (Vahl) (Obomanu et al., 2006), Ageratina adenophora Spreng. (RajMohan and Ramaswamy, 2007), Ocimum sanctum L. (Anees, 2008) and Allium sativum L. (Kalu et al., 2010). The present investigation was carried out to determine the larvicidal adult emergence inhibition effects of benne seed, Sesamum indicum L. (Pedaliaceae) against Cx. quinquefasciatus. MATERIALS AND METHODS The leaves of S. indicum collected from St. Joseph’s College Campus, Tiruchirappalli, Tamil LARVICIDAL AND ADULT EMERGENCE INHIBITION EFFECTS OF BENNE SEED, SESAMUM INDICUM L. (PEDALIACEAE) AGAINST MOSQUITO, CULEX QUINQUEFASCIATUS (SAY), (DIPTERA: CULICIDAE) IN THREE WATER SAMPLES IN VITRO K. RAJAN*, M. S. MCCONNELL, X. BASKAREN, S. SIVARAMA KRISHNAN 1 AND S. JESU RAJAN 1 Department of Plant Biology and Plant Biotechnology, St. Joseph’s College (Autonomous), Trichy – 620 002, Tamil Nadu, India. email: profkilimas_rajan@yahoo.com 1 Entomology Research Unit, St. Xavier’s College (Autonomous), Palayamkottai – 627 002, Tamil Nadu, India. ABSTRACT The present study was conducted to evaluate the larvicidal and adult emergence inhibition effects of benne seed, Sesamum indicum L. (Pedaliaceae) against the mosquito, Culex quinquefasciatus (Say), in three types of water samples: sewage water, pond water and tap water in vitro. Methanol extracts from the leaves of S. indicum at two ranges of concentration viz., 0.01 to 0.17 and 0.33 to 5.0 were tested against the larvicidal activity against the larvae of Cx. quinquefasciatus. At lower concentrations of extract (0.01 to 0.17%) no larval mortality was observe in all the water samples. When the concentration of the extract was increased to 0.33 to 5% the total larval mortality (100%) was observed in all the water samples. At lower concentration, the adult emergence was 100% but at higher concentration 90% inhibition of adult emergence was observed. Key words: Mosquito, Culex quinquefasciatus, Sesamum indicum, adult emergence inhibition, larvicidal activity * Corresponding author Insect Pest Management, A Current Scenario, 2011 (ed.), Dunston P. Ambrose, Entomology Research Unit, St. Xavier’s College, Palayamkottai, India, pp.501-504.