The wasp bees (Nomada) of the Netherlands (Hymenoptera: Apidae) In the Netherlands 44 species of Nomada are known to occur. The name wasp bee is derived from the often yellow and black colour, which give the insects a wasplike appearance. Nomada bees are cleptoparasites mostly with Andrena species. The eggs are laid in the nest of the host and the Nomada larvae destroys the egg of the host and feeds on the pollen supply. In this paper a key to the males and females of the Netherlands and surrounding area is given. In the species descriptions information is given on the morphology, distribution, hosts, flower visits, fenology and red list status.