With over 850 species, the genus Nomada is one of the largest genera in the family Apidae, and the largest genus of cleptoparasitic "cuckoo bees". They occur worldwide, and use many different types of bees as hosts, primarily the genus Andrena. As parasites, they lack a pollen-carrying scopa, and are often extraordinarily wasp-like in appearance, with red, black, and yellow colors prevailing, and with smoky (infuscated) wings or wing tips.
Separation of this genus (the only genus in the tribe Nomadini) from other members of the Nomadinae can be difficult; details of the wing venation, and the nature of the patch of silvery setae at the tip of the female metasoma are the best distinguishing features.
See List of Nomada species for a complete list.