The black fly Greniera michiganensis Taber is described from the western Lower Peninsula of Michigan. Larvae were found in a cold, shallow, narrow, ephemeral rill, on the lower surface of barely submerged leaves of black oak, Quercus velutina Lamarck, and on a few barely submerged leaves of quaking aspen, Populus tremuloides Michaux. The species is most similar to Greniera denaria (Davies, Peterson and Wood) but differs in larval, pupal, and adult morphology. According to the standard reference on North American Simuliidae, this is the first record of the genus from Michigan.