RESEARCH PAPER Evaluation of larvicidal potential of certain insect pathogenic fungi extracts against Anopheles stephensi and Culex quinquefasciatus Prejwltta MAURYA, Lalit MOHAN, Preeti SHARMA and C. N. SRIVASTAVA Applied Entomology & Vector Control Laboratory, Department of Zoology, Faculty of Science, Dayalbagh Educational Institute (Deemed University), Dayalbagh, Agra, India Correspondence C.N. Srivastava, Applied Entomology & Vector Control Laboratory, Department of Zoology, Faculty of Science, Dayalbagh Educational Institute (Deemed University), Dayalbagh, Agra-282110, India. Email: chandnarayan_dei@rediffmail.com Received 26 July 2010; accepted 7 September 2011. doi: 10.1111/j.1748-5967.2011.00347.x Abstract Fungal metabolites are attracting attention as potential microbial insecticides, and they are anticipated to overcome the problems of pesticide resistance and environ- mental pollution that are associated with the indiscriminate use of conventional synthetic insecticides. The relative bioefficacies of selected fungal pathogens, Aspergillus flavus, A. niger, A. parasiticus, Fusarium sporotrichoides and Penicil- lium verrucosum were observed against Anopheles stephensi and Culex quinque- fasciatus larvae. A. flavus demonstrated the greatest bioefficacy with 50% lethal concentration (LC 50) values of 9.54 and 10.98 ppm against Anopheles stephensi and Culex quinquefasciatus larvae, respectively, after 24-h exposure. The bioeffi- cacy of A. flavus increased in both species with an exposure time of 48 h, with LC 50 values of 7.26 and 8.55 ppm, respectively. Key words: Anopheles stephensi, Aspergillus spp., Cx. quinquefasciatus, F. sporotrichoides, P. verrucosum. Introduction Synthetic pesticides and their residues are a source of envi- ronmentally related hazards and pesticide resistance. There- fore, screening microbial extracts as potential insecticides was conducted to determine their potential as a viable alter- native for vector-borne disease management (Ignacimuthu & Paul-raj 2009). Mosquitoes are the most important vector for several vector-borne pathogens, that is, malaria with 300–500 million reported cases and 1.1–2.7 million deaths annually, and filariasis, a debilitating disease which is endemic in many of the tropical and subtropical regions of the world and with >120 million people infected worldwide, of which 44 million demonstrate common chronic disease manifestations (Bernhard et al. 2003; Wernsdorfer & Wernsdorfer 2003). The applications of microbial insecticides are preferred as same exhibit selective toxicity, do not persist after applica- tion, are relatively safer to produce and possess fewer non- target organism environmental hazards (Misato 1983). Fungi are among the most important entomopathogenic microbes and are a source of potential biological control agents. Unlike bacteria, nematodes and protozoans, the infectious propagules (conidia) of fungi, do not need to be ingested. Instead, contact with the insect cuticle is sufficient for the propagules to infect the mosquitoes. Therefore, these ento- mopathogenic fungi may provide an environmentally safe and effective method for mosquito control. The toxicity of the soil-borne fungi extracts of Aspergillus flavus, A. niger, A. parasiticus, Fusarium sporotrichoides and Penicillium verrucosum were evaluated for their relative toxicity against Anopheles stephensi and Culex quinquefas- ciatus larvae. Materials and methods Isolation of fungi Dilutions of soil samples were collected from different areas of Dayalbagh, Agra, India, and stored at 4°C. Isolation of Entomological Research 41 (2011) 211–215 © 2011 The Authors Entomological Research © 2011 The Entomological Society of Korea and Blackwell Publishing Asia Pty Ltd