European June beetle, Amphimallon solstitiale Linnaeus, 1758 (Coleoptera: Scarabaeidae) is one of the most important soilbome pests in many parts of Turkey and the world. Entomopathogenic fungi are important microbial control agents that can be used to control soilborne pests, and it is desirable to obtain them from local insect populations. The study was conducted at Karadeniz Technical University, Faculty of Science, Microbiology Laboratory in 2017. In this study, fungal pathogens of A. solstitiale were investigated to find an effective microbial control agent. Fungi were isolated from infected larvae and morphological-molecular characterization of the isolates showed that all isolates were Metarhizium flavoviride Gams & Roszypal (Deuteromycotina: Hyphomycetes). Using phylogenetic analysis and pathogenicity tests, the isolates were found to be different genotypes of M. flavoviride. All isolates gave more than 80% mortality at a concentration of 10(6 )conidia/mI, with one isolate (As2) causing 96% mortality. Therefore, dose-mortality experiments were conducted with As2, and the median lethal concentration was determined to be 3.87 x 10(3) conidia/ml. This study demonstrated that M. flavoviride As2 is an effective microbial control agent that can be used for biological control of A. solstitiale.