Anthophoridae are almost all inquilines in the nests of various solitary bees. Graenicher (1905b) presented an account of Triepoelus helianthi Rob. as an inquiline in the nests of Melissodes trinodis Rob. Triepoelus seems to lay its egg in the food material, and the 1st instar larva appears generally like that of Coelioxys, with similar habits. Abdominal segments bear a flat triangular projection at each lateral margin. The very large falcate mandibles are thought to be useful against larvae of their own species rather than to fend off the host bee. The host preferences of a number of species was reviewed by Perkins (1919), showing that each nomadid is closely associated with a particular host species.