The control of house flies, (L.), currently relies on the use of chemical insecticide spray and bait formulations. Entomopathogenic fungi, such as , may provide an alternative to these products. This study aimed to develop and evaluate a mycoinsecticide bait formulation containing a virulent isolate. Five isolates were screened against and isolate M16 was selected for bait development. Bait formulations containing a variety of additives, including (Z)-9-tricosene, were tested for their ability to increase fly visitation. A bait formulation containing and skim milk powder was found to have the highest house fly visitation and was subsequently compared to a conventional chemical bait in an efficacy assay. The chemical bait (0.5% imidacloprid) caused faster mortality than the mycoinsecticide bait, however, similar levels of mortality were achieved by 4-5 days' post exposure. These results suggest that mycoinsecticide baits may offer an alternative to conventional chemical insecticides for the control of house flies in suitable areas.