Epeoloides pilosula (Cresson) (Hymenoptera: Apidae), a cleptoparasitic bee thought to be extinct, was recently discovered in Nova Scotia, Canada. This, the first documented capture in over 60 years, expands the reported range of this species in North America which coincides with that of its host, bees of the genus Macropis (Melittidae). Macropis bees are floral oil collection specialists which are themselves dependant on and thus confined within the range of their food plant Lysimachia (Primulaceae). The restrictions inherent within this triumvirate are factors contributing towards the tenuous existence of E. pilosula, one of the rarest bees in North America.