Nomada

Scopoli, 1770

Nomad Bees, Cuckoo Bees

Species Guides

35

Nomada is one of the largest in the Apidae, with over 850 worldwide. These bees are kleptoparasites that lay in the nests of other bees, primarily ground-nesting species in the genus Andrena. bees lack pollen-carrying scopa and are mostly hairless, feeding on nectar but not collecting pollen for offspring. The genus name derives from the Greek word for 'roaming' or 'wandering,' reflecting their parasitic lifestyle.

Nomada articulata by (c) Paul Prior, some rights reserved (CC BY), uploaded by Paul Prior. Used under a CC-BY license.Nomada gracilis by (c) Bernie Paquette, some rights reserved (CC BY), uploaded by Bernie Paquette. Used under a CC-BY license.Nomada gracilis by (c) Bernie Paquette, some rights reserved (CC BY), uploaded by Bernie Paquette. Used under a CC-BY license.

Pronunciation

How to pronounce Nomada: //noˈma.da//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Difficult to separate from other Nomadinae; best distinguished by wing venation details and the nature of the silvery setae patch at the female metasoma tip. Females identifiable by lack of scopa, reduced body hair, thick , and . Males identifiable by the notched pygidial plate. Often mistaken for due to wasp-like appearance and lack of pollen-collecting structures.

Images

Appearance

Extraordinarily -like in appearance with prevailing red, black, and yellow coloration. Most have smoky (infuscated) wings or wing tips. Integumental markings vary greatly between species: some are stripeless, while others display yellow or white abdominal markings. Females possess specialized patches of hair at the tip of the metasoma and lack scopa entirely. Males exhibit an obvious, often notched pygidial plate. Body is mostly hairless with a thick .

Habitat

correlate with those of bees, primarily ground-nesting bees in open habitats or vegetation-covered areas with good floral sources nearby. Requires bare or sparsely vegetated soil for host nest access. Associated with habitats supporting Andrena and other host including coastal meadows, woodland rides, brownfield sites, and soft cliffs.

Distribution

Worldwide distribution. Documented from North America (including Michigan, New York, Illinois, Colorado, New Mexico, Vermont), Europe (including Scandinavia, Germany, Britain, Ireland), and other regions. Specific show varying ranges: Nomada zonata colonized Britain in 2016 and has rapidly expanded northward; Nomada sexfasciata restricted to south Devon coast in UK.

Seasonality

Activity periods vary by and correlate with . Generally active from early spring through summer. Some species associated with spring hosts (e.g., Andrena) active March–June; others with summer hosts active later. Nomada colorata recorded in Illinois suggests spring–summer activity.

Diet

feed on nectar from flowers. Larvae consume pollen and nectar provisions collected by bees.

Host Associations

Life Cycle

Holometabolous development: → larva → pupa → . Female deposits 1–2 eggs per , sometimes burying eggs at right angles into cell walls or partially inserting them. Multiple eggs may be laid in single host cells. Larvae hatch and use to kill host eggs/larvae and any competitors until only one survivor remains. Survivor consumes host provisions, pupates in host cell, and emerges as adult the following season.

Behavior

Females locate nests using visual cues and olfactory assessment of vulnerability, host presence, and competition. Males secrete host-mimicking from mandibular glands to mark areas near host nests, facilitating female host location. Males patrol host nesting areas and 'swarm' vegetation such as willow and gooseberry. Copulation involves 'antennal grabbing' where males spiral around female antennae to transfer pheromones. exhibit unusual sleeping , holding onto plants using only .

Ecological Role

Kleptoparasite of ground-nesting bees. Considered poor due to lack of scopa and pollen-collecting . May influence and structure. Serves as indicator of healthy host and quality.

Human Relevance

Subject of conservation concern for rare and their . Six-banded Nomad Bee (Nomada sexfasciata) is UK's rarest , dependent on conservation of Long-horned Bee . management for host bees (bare ground creation, flower-rich grassland restoration) indirectly benefits Nomada species. Some species expanding range due to climate change (e.g., Nomada zonata).

Similar Taxa

Misconceptions

Often mistaken for due to hairless, wasp-like appearance and lack of pollen-carrying structures. Not all are yellow-and-black striped; coloration varies extensively. Despite poor pollination ability, do visit flowers for nectar and contribute marginally to pollination.

More Details

Chemical mimicry

Males produce mandibular gland secretions chemically identical to secretions of female bees, transferred to females during antennal grabbing. This may provide camouflage for nest entry and/or make females unattractive to other males.

Conservation status

Multiple of conservation concern: Nomada sexfasciata (Endangered in UK), Nomada obtusifrons (Endangered in Ireland), Nomada striata (rare in Northern Ireland). Threatened primarily by declines due to loss.

Range expansion

Nomada zonata colonized Britain in 2016 and has rapidly expanded northward into West Midlands by 2024, possibly facilitated by ability to fly over large water bodies and climate change.

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Sources and further reading