Abstract
Background: Due to the effect of synthetic and commercial insecticides on non-target organisms and the resistance of mosquitoes, in recent years non-chemical and environmentally friendly methods have become prevalent. In this research, we aimed to isolate entomopathogenic fungi with toxic effects on mosquitoes in natural larval habitats.Methods: Larval mosquitos were collected from Central, Qamsar, Niasar and Barzok Districts in Kashan County, Central Iran by standard dipping method, from April to late December 2019. Dead larvae and larvae with signs of infection to fungal mycelium detectable on the outer surface of its body were isolated from the rest of the larvae and were sterilized with 10% sodium hypochlorite for two minutes, then washed twice with distilled water and transferred to PDA (potato-dextrose-agar) and WA (water-agar) media and incubated at a temperature of 25 ± 2° C for 3 - 4 days. Larvae and fungi were identified morphologically based on identification keys.Results: A total of 9789 larvae were collected from urban and rural areas in Kashan County. The genera i.e. Anopheles (7.89%), Culiseta (17.42%), and Culex (74.69%) including 13 species were identified. A total of 105 larvae including Anopheles superpictus s. l., An. maculipennis s. l., Culex deserticola, Cx. perexiguus, and Culiseta longiareolata were found to be infected by Nattrassia mangiferae, Aspergillus niger, A. fumigatus, Trichoderma spp. and Penicillium spp. Fungi. Penicillium spp. was the most abundant fungus isolated and identified from the larval habitats while An. superpictus s.l. was the most infected mosquito species. Conclusions: Based on the observations and results obtained from our study, isolated fungi had the potential for pathogenicity on mosquito larvae. Therefore, it is suggested that their effects on mosquito larvae be investigated in the laboratory. The most important point, however, is the proper way of exploiting these biocontrol agents to maximize their effect on reducing the population of vector mosquito larvae without any negative effect on non-target organisms.