A cuckoo bee

Scientific Name

(Nomada rubicunda)

Nomada rubicunda is a rare species of nomad bees, which are cleptoparasites. Most Nomada species parasitize Andrena bees, but N. rubicunda is part of the few that parasitize bees of the Agapostemon genus (1), specifically A. splendens (2, 3). The species is uncommonly called the ruddy nomad bee. Historically it ranged from New York to Florida, and west towards Minnesota and Texas (4, 5). Currently, only a few records exist in Maryland, the most recent ones in Worcester County (2, 3).

Identification

Nomad bees are wasplike, with hairless bodies, and red and yellow coloring; they are the only bees found in North America that may be fully red (1). Nomada rubicunda females have a primarily red body with almost no yellow markings and white bands on the fourth and fifth abdominal segments. The females' hind tibiae have a brown blade-like seta that sticks out. Male N. rubicunda have a black body with prominent yellow markings. The males are one of a few species that have a short yet distinct spine under the third flagellar segment of their antennae. In general, male nomad bees have a prominent pygidium plate at the end (4).

Life cycle  

Nomad bees hover close to the ground in search of empty bee nests of their host. If the nest is occupied they will cling to a blade of grass or hang from a twig while waiting for the female host to leave. Once the host is gone, nomad females will lay up to four eggs in a host's nest cell. One egg will hatch into a motile larva with pincers that destroys both its host's and siblings' eggs before feeding on stored pollen (1). Nomad bees primarily emerge in spring where they feed on nectar and search for mates (6).

Nomada rubicunda is in flight from March to June (4, 6). They are parasites of Agapostemon splendens (shown right), commonly known as the brown-winged striped-sweat bee (7). The flowers N. rubicunda prefers to visit for nectar include those of the Crataegus, Fragaria, Melilotus, and Rubus genera (4).