Abstract. – Objective: To determine the larvicidal efficacy of different solvent leaf extract of Ervatamia coronaria and Caesalpinia pulcherri- ma against Anopheles subpictus and Culex tri- taeniorhynchus. Materials and Methods: Twenty five early third instar larvae of Anopheles subpictus and Culex tritaeniorhynchus were exposed to various concentrations and were assayed in the labora- tory. The larval mortality was observed after 24 h of treatment. Results: Among three solvent extracts tested the maximum efficacy was observed in the methanol extract. The LC 50 (LC 90 ) values of Er- vatamia coronaria and Caesalpinia pulcherrima against early third instar of Anopheles subpictus were 86.47 (159.59) and 113.26 (207.73) ppm and Culex tritaeniorhynchus were 131.53 (245.37) and 165.28 (299.45) ppm, respectively. No mortality was observed in controls. Conclusions: From the results it can be con- cluded the crude extract of Ervatamia coronaria and Caesalpinia pulcherrima were excellent po- tential for controlling Anopheles subpictus and Culex tritaeniorhynchus mosquito larvae. Key Words: Larvicidal activity, Anopheles subpictus, Culex tritae- niorhynchus, Ervatamia coronaria, Caesalpinia pul- cherrima. Introduction Mosquitoes are the major vector for the trans- mission of malaria, dengue fever, yellow fever, filariasis, schistosomiasis and Japanese en- cephalitis (JE), etc. causing millions of deaths European Review for Medical and Pharmacological Sciences Corresponding Author: M. Govindarajan, Ph.D.; e-mail: drgovind1979@rediffmail.com every year 1 . Mosquitoes also cause allergic re- sponses in humans that include local skin and systemic reactions such as angioedema 2 . Anophe- les (An.) subpictus is known to transmit malaria and filariasis, in an isolated study of multiple host-feeding in field populations, and its specific role in transmitting malaria in Sri Lanka revealed that multiple blood feeding within the same gonotrophic cycle was attributed to a local “fre- quent feeding strategy” in this primarily zoophagic and endophilic malaria vector. On the contrary, in Indonesia, An. subpictus is a poten- tial vector of bancroftian filariasis and fed on mi- crofilaraemia carriers that harbored Wuchereria bancrofti larvae 3 . An. subpictus breeds profusely in rainwater accumulations and fallow rice fields 4 , waste water disposal systems, and irrigat- ed sites 5 , and is also associated with floating and submerged aquatic vegetation in the vicinity of rice plants 6 . Night time human biting collection in Rajasthan, India, showed two feeding peaks for An. subpictus, one early in the night and the other just before dawn 7 . Culex tritaeniorhynchus Giles is an important vector of JE in India and South East Asian countries. JE is endemic in few states of India and highly endemic in few dis- tricts of Tamil Nadu, Southern India 8 . Keiser et al 9 have reported that approximately 1.9 billion people currently live in rural JE prone areas of the world, the majority of them in China (766 million) and India (646 million). Mosquito control has been become increasing difficult of the indiscriminate uses of synthetic chemical insecticides which has an adverse im- pact on the environment and disturb ecological balance. Majority of the chemical pesticides are harmful to man and animals, some of which are not easily degradable and spreading toxic effects. 2012; 16: 386-392 Larvicidal efficacy of botanical extracts against two important vector mosquitoes M. GOVINDARAJAN 1 , R. SIVAKUMAR 1 , A. AMSATH 2 , S. NIRAIMATHI 3 1 Division of Vector Biology and Phytochemistry, Department of Zoology, Annamalai University, Annamalainagar (India) 2 Postgraduate & Research Department of Zoology, Khadir Mohideen College, Adirampattinam (India) 3 Postgraduate & Research Department of Biochemistry, RVS College of Arts and Science, Karaikal (India) 386