Hyphomycetous Fungi Isolated from Insects and Their Pathogenic Effect on Colorado Beetle in Hamedan Province

Document Type : Research Article



Insect biocontrol by entomopathogenic fungi can be a suitable substituting method for chemical insecticide or at least can be used as complementary the chemical insecticides. In this study 42 fungal isolates belonging to 12 species were isolated and identified from different insects. Among obtained fungal isolates, seven isolates were used in pathogenicity trials on Colorado beetle larva in Hamedan province. The study was achieved under factorial test and completely randomly design. Results showed that all fungal isolates were pathogenic on Colorado beetle larva and mortality percent of larva were increased with increasing concentration of fungal spore suspension. Application of spore suspension in concentration of 107 spore per milliliter of fungal isolates comprising Beauveria bassiana (two isolates), Paecilomyces sp. (two isolates), Isaria farinosa, Trichoderma koningiopsis and Fusarium verticillioides caused 100, 100, 42.2, 42.2, 37.5, 28.37 and 17.7 percent larva mortality respectively. It was conducted that B. bassiana isolates were the most pathogenic agent on Colorado beetle larva. In addition effect of insecticides Danito and Desis on spore germination and mycelia growth of B. bassiana was investigated. Results showed that these insecticides have a little effect s on B. bassiana. Therefore integrated control of Clorado beetle can be achieved by application of B. bassiana and these insecticides in concentration of under lethal dose.

Keywords: Biological control, Potato, Beauveria bassiana, Leptinotarsa decemlineata