Entomopathogenic fungi offer promising and environmentally friendly alternatives to chemical insecticides for pest management in turfgrasses. Commercialized entomopathogenic fungi registered for application to turfgrasses primarily use Beauveria bassiana GHA (Botanigard) or Metarhrizium brunneum F52 (Met52) as the active agents. Strain adaptation to local environments could improve the efficacy of biological control organisms. So, in 2014, 37 novel strains of entomopathogenic fungi were isolated from the soils of several horticultural sites in Oklahoma and assayed for virulence against waxworms and mealworms. The five most virulent strains which included four strains of M. robertsii (OK78, OK87, OK106A, and OK205) and one strain of M. lepidiotae (OK102) were selected for laboratory bioassays and field trials against black cutworm (Agrotis ipsilon), a turfgrass-defoliating caterpillar pest. In both laboratory bioassays and field trials these fungal strains caused high mortality (82.6%-to-90.6%) to black cutworms. Based on these results, the efficacy of each fungal strain against another turf pest, fall armyworm (FAW) (Spodoptera frugiperda) larvae, was assessed in laboratory bioassays and field trials. In 6 cm diameter laboratory bioassay cups, second instar FAW larvae (n=25 per treatment) were co-incubated with 1 g negative control sterile proso millet grains or sterile proso millet grains inoculated with each of the five native Metarhizium strains or with positive control M. brunneum F52. Mortality was assessed at 2-, 4-, 6-, and 8-days after-treatment (DAT). In field trials, screened, 46 cm diameter PVC corrals (n = 4 plots per treatment) on ‘Tyee’ bentgrass putting greens (OSU Turfgrass Research Center, Stillwater, OK) infested with 25 FAW eggs and inoculated with 10 g proso millet grains inoculum of each fungus or sterile proso millet seed control. One day prior, 4 plots were treated with bifenthrin (Talstar P at 0.2 fl. oz. per 1,000 sq. ft.). After 14 days, larval mortality (%) and turf damage ratings were evaluated. A high rate of mortality was observed in FAW larvae both in laboratory bioassays and field trials. The next objective of this study was to calculate LC50 (Lethal Concentration 50%), Mortality data were analyzed using probit analysis to determine the effective range of spore suspension concentrations per application for each strain. The LC50 values were as follows: OK78 - 4.2 x 10^5 conidia/mL, OK87 - 1.74 x 10^5 conidia/mL, OK102 - 2.82 x 10^5 conidia/mL OK106A - 6.31 x 10^5 conidia/mL, and OK205 - 3.63 x 10^5 conidia/mL. This study showcases the promising potential of these novel Metarhizium strains as effective biopesticides in turfgrass pest management.