The bees of Michigan (Hymenoptera: Apoidea: Anthophila), with notes on distribution, taxonomy, pollination, and natural history Author Gibbs, Jason Author Ascher, John S. Author Rightmyer, Molly G. Author Isaacs, Rufus text Zootaxa 2017 2017-11-21 4352 1 1 160 journal article 31367 10.11646/zootaxa.4352.1.1 543c4afc-4ffb-4e11-a858-a6d1d9745214 1175-5326 1063854 7C684128-FFA7-48AA-B395-B9C6BC39353A Genus Nomada Scopoli Taxonomy: Alexander & Schwarz (1994) ; Broemeling & Moalif (1988) ; Droege et al. (2010) ; Evans (1972) ; Mitchell (1962) ; Schwarz & Gusenleitner (2004) . Nomada is in serious need of revision, especially the species-rich ruficornis group, which may be paraphyletic and includes a particularly challenging subgroup of species with bidentate mandibles. Nomada is the most problematic genus for the state and the following list is likely to be changed substantially following taxonomic revision of the genus. Biology. All Nomada are cleptoparasites. Hosts are primarily within the genus Andrena (the known or suspected host of species in the ruficornis and vincta groups), but bees in other families are also be attacked including halictid ( e . g ., Agapostemon by species in the erigeronis and vegana groups) and apid ( e . g ., Eucera by species in the superba group) bees.