Entomopathogenic fungi have significant potential to control mosquito population. The culture filtrates of Fusarium oxysporum, Lagenidium giganteum, Trichophyton ajelloi, and Culicinomyces clavisporus were evaluated against adults of Cx. quinquefasciatus. The culture filtrates were obtained by filtering the broth through Whatman-1 filter paper. These culture filtrates of C. clavisporus have been found significantly pathogenic with LC50-2.5, LC90-7.24, and LC99-8.7？ML, respectively, after exposure of 24？h. However, the culture filtrates when were combined, in ratios 1？:？1？:？1 of Fusarium oxysporum, Lagenidium giganteum, Trichophyton ajelloi the mortalities were significantly increased. The LC50-3.71, LC90-8.12, and LC99-11.48 were significantly recorded after exposure of 10？hrs. Similarly, the culture filtrates of T. ajelloi, Culicinomyces clavisporus, and L. giganteum have been combined in ratios 1？:？1？:？1. Similarly the LC50-1.94, LC90-4, and LC99-6.16？ML Were recorded after exposure of 10？hrs. The results of present study show promise for the use of selected fungal metabolites for control of Cx. quinquefasciatus in the Laboratory. 1. Introduction Fungus entomopathogens show potential as alternative biological control agents against mosquitoes and used as currently developed fast action chemical insecticides . The mosquito pathogenic fungi that target larval instars include the chytridiomycetes Coelomomyces [2, 3]. Only few studies have evaluated these pathogens against the adult stage of tropical disease vectors. In adults Ochlerotatus sierrensis infected with the deuteromycete Tolypocladium cylindrosporum, there was 100% mortality after ten days . Scholte et al.  reported that also adults of An. gambiae were susceptible to B. bassiana, Fusarium spp., and Metarhizium anisopliae. So far the extracellular secondary metabolites from three hundred and fifty fungi and ninety four actinomycetes have been screened for larvicidal activity against Cx. quinquefasciatus, An. stephensi, and Ae. aegypti . The metabolites of Chrysosporium tropicum have been found highly pathogenic as adulticides against An. stephensi, Cx. quinquefasciatus, and Ae. aegypti . Therefore, the fungi are weapons with great potential in mosquito vector control . Recently, Paula et al.  investigated the combinated effect of M. anisopliae with the insecticide Imidacloprid increasing the virulence of the fungus against the dengue vector Ae. aegypti, whilst the use of entomopathogenic fungi against mosquitoes has provided encouraging results under controlled laboratory
G. G. Soares Jr., “Pathogenesis of infection by the hyphomycetous fungus, Tolypocladium cylindrosporum in Aedes sierrensis and Culex tarsalis [Dip.: Culicidae],” Entomophaga, vol. 27, no. 3, pp. 283–300, 1982.
E. J. Scholte, W. Takken, and B. G. J. Knols, “Pathogenicity of six East African entomopathogenic fungi to adult Anopheles gambiae s.s. (Diptera: Culicidae) mosquitoes,” in Proceedings of the Experimental and Applied Entomology, vol. 14, pp. 25–29, NEV, Amsterdam, The Netherlands, 2033.
P. Verma and S. Prakash, “Efficacy of Chrysosporium tropicum metabolite against mixed population of adult mosquito (Culex quinquefasciatus, Anopheles stephensii, and Aedes aegypti) after purification with flash chromatography,” Parasitology Research, vol. 107, no. 1, pp. 163–166, 2010.
A. R. Paula, A. T. Carolino, C. O. Paula, and R. I. Samuels, “The combination of the entomopathogenic fungus Metarhizium anisopliae with the insecticide Imidacloprid increases virulence against the dengue vector Aedes aegypti (Diptera: Culicidae),” Parasites and Vectors, vol. 4, no. 1, p. 8, 2011.
L. L. Mnyone, T. L. Russell, I. N. Lyimo, D. W. Lwetoijera, M. J. Kirby, and C. Luz, “First report of Metarhizium anisopliae IP 46 pathogenicity in adult Anopheles gambiae s.s. and An. arabiensis (Diptera; Culicidae),” Parasites and Vectors, vol. 2, no. 1, p. 59, 2009.
L. L. Mnyone, M. J. Kirby, M. W. Mpingwa et al., “Infection of Anopheles gambiae mosquitoes with entomopathogenic fungi: effect of host age and blood-feeding status,” Parasitology Research, vol. 108, no. 2, pp. 317–322, 2010.
A. F. V. Howard, R. N'Guessan, C. J. M. Koenraadt et al., “First report of the infection of insecticide-resistant malaria vector mosquitoes with an entomopathogenic fungus under field conditions,” Malaria Journal, vol. 10, p. 24, 2011.
G. Singh and S. Prakash, “Evaluation of culture filtrates of Culicinomyces clavisporus: mycoadulticide for Culex quinquefasciatus, Aedes aegypti and Anopheles stephensi,” Parasitology Research. In press.
A. L. Demain and A. Fang, “The natural functions of secondary metabolites,” in History of Modern Biotechnology, T. Scheper, Ed., vol. 69 of Advances in Biochemical Engineering Biotechnology, pp. 1–39, Springer, Berling Heidelberg, Germany, 2000.