%0 Journal Article
%T Relative Toxicity of Leaf Extracts of Eucalyptus globulus and Centella asiatica against Mosquito Vectors Aedes aegypti and Anopheles stephensi
%A Savitha Sekhar Nair
%A Vinaya Shetty
%A Nadikere Jaya Shetty
%J Journal of Insects
%D 2014
%R 10.1155/2014/985463
%X The larvicidal activity of different solvent leaf extracts (hexane, diethyl ether, dichloromethane, and methanol) of Eucalyptus globulus and Centella asiatica against two geographically different strains of Aedes aegypti and Anopheles stephensi was investigated. The extracts were tested against the late third instar larvae of Aedes aegypti and Anopheles stephensi, and larval mortality was observed after 24 hours of treatment. LC50 and LC90 were calculated. The LC50 values of hexane extract of Eucalyptus globulus against the late third instar larvae of the BSN and JPN strains of Aedes aegypti and the DLC and KNG strains of Anopheles stephensi were 225.2, 167.7, 118.8, and 192.8£¿ppm, while those of the hexane extract of Centella asiatica were 246.5, 268.7, 50.6, and 243.5£¿ppm, respectively. The LC50 values of diethyl ether extract of Centella asiatica were 339.6, 134.5, 241, and 14.7£¿ppm. The hexane extracts of both plants and the diethyl ether extract of C. asiatica presented the highest potential for the control of Aedes aegypti and Anopheles stephensi. The present findings also reveal the necessity of assaying multiple strains of a species to fully comprehend the larvicidal efficacy of a compound. 1. Introduction Apart from being a social nuisance, mosquitoes pose serious health threats to both men and animals considering that they are the principal vectors for many vector borne diseases including malaria, dengue, yellow fever, and Chikungunya [1, 2] in men and equine encephalitis, haemorrhagic septicaemia of buffaloes, and enzootic hepatitis in animals [3]. In some individuals, mosquito bites also result in acute systemic allergic reactions defined by the presence of one or more of the following: urticaria, angioedema, wheezing, dyspnea, hypotension, and decrease or loss of consciousness [4]. The mosquito, Aedes (Stegomyia) aegypti (Linn.), (Diptera: Culicidae) is the primary vector of dengue, yellow fever, and Chikungunya [2]. According to WHO, over 40% of the world¡¯s population is now at risk of dengue and there are 200£¿000 estimated cases of yellow fever, causing 30£¿000 deaths, worldwide each year. Malaria, on the other hand, a life threatening disease which caused an estimated 627£¿000 deaths in 2012 is transmitted exclusively through the bites of Anopheles mosquitoes [5]. Anopheles stephensi Liston (Diptera: Culicidae) is a major vector in India as well as in some of the West Asian countries and has been shown to be directly responsible for about 40¨C50% of the annual malarial incidence [6, 7]. Mosquito control is an extensively researched topic
%U http://www.hindawi.com/journals/insects/2014/985463/