Beetles of Family Melandryidae occur under the bark of mature and rotting trees, but have been poorly studied and their life histories have seldom been described. They are thought to feed on rotting wood or fungal hyphae. Recently, adults and larva of Orchesia cultriformis Laliberté were collected while feeding on the basidiocarp tissue of a polypore fungus, Inonotus obliquus (Ach. ex Pers.), and dissected, with their gut contents all found to contain hyphae and spores positively identified to be those of I. obliquus. Inonotus obliquus (“chaga”) is a ubiquitous fungus found in northern latitudes of North America, Europe, and Asia. The species is very well-known and highly prized commercially for purported pharmacological benefits including cancer-fighting properties. Despite its universal recognizability, many questions about the basic biology of this fungus remain, including sexual reproduction and spore dispersal which has rarely been seen. Mycophagous beetles have been hypothesized as having a role. This is the first report of insect mycophagy of I. obliquus in North America, and these findings suggest that O. cultriformis may play a role in spore dispersal of this enigmatic fungus.