Nomadini

Distinguished from other Apidae by cleptoparasitic lifestyle indicators: absence of scopa, wasp-like slender build, and often smoky wings. Separated from actual wasps by wing venation and other hymenopteran characters. Within Nomadinae, genus-level identification relies on color pattern, facial markings, and antennal structure. Species identification requires examination of subtle morphological details including punctation density, clypeal shape, and genitalia.

Adults exhibit wasp-like morphology with slender bodies, reduced hairiness, and striking color patterns of red, black, and yellow. Wings are often smoky or infuscated at the tips. Unlike pollen-collecting bees, they lack a scopa (pollen-carrying structure) on the legs or abdomen. Body size varies by species but generally small to medium.

Found in diverse habitats where host bees occur, including grasslands, meadows, woodland edges, brownfield sites, coastal cliffs, and gardens. Nesting aggregations of host bees, particularly Andrena species in sandy or clay soils, are key habitat features. Sunny south-facing slopes and banks are frequently utilized.

Worldwide distribution with highest diversity in temperate regions. In Europe, widespread with species-specific ranges. Some species restricted to coastal areas (e.g., Nomada sexfasciata in South Devon, UK). First records continue to be documented (e.g., Nomada numida in mainland France, 2017).

Active primarily spring through summer, with flight periods synchronized to host bee emergence. Most species active from April to July in temperate regions, though timing varies by species and latitude. Males typically emerge before females.

• Andrena - primary hostMost Nomadini species parasitize mining bees in genus Andrena

Obligate cleptoparasitism: females locate host nests using chemical cues, enter unsealed cells, and lay eggs. Larvae hatch and kill host egg or larva, then consume stored pollen and nectar provisions. Development occurs within host cell; adults emerge following season.

Females hover near host nest entrances, waiting for host to depart before entering to oviposit. Males patrol nest aggregations seeking females. Some species exhibit host-specificity while others are generalists. Adults visit flowers for nectar but do not collect pollen.

Population regulation of host bee species. As cleptoparasites, they influence nesting success and local abundance of Andrena and related bees. Contribute to pollination indirectly through nectar feeding.

Indicators of healthy solitary bee populations and habitat quality. Subject of conservation concern where host species are rare (e.g., Six-banded Nomad Bee in UK). Some species observed in gardens and urban parks.

• Sphecodes (Blood Bees)Also cleptoparasitic bees with red and black coloration, but in family Halictidae; differ in wing venation and facial structure
• Coelioxys (Sharp-tailed Bees)Cleptoparasitic Megachilidae with pointed abdomen; differ in host association (Megachile) and abdominal shape
• Vespidae (wasps)Similar wasp-like appearance but differ in wing folding, petiole structure, and behavior; wasps are not cleptoparasites of bees

Often mistaken for wasps due to coloration and lack of pollen-carrying structures; this resemblance is convergent, not indicative of close relationship.

• cleptoparasite
• cuckoo bee
• solitary bee
• Andrena parasite
• wasp mimic

• BugGuide
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Not-so Solitary Bees - Buglife Blog - Buglife
• Gardening for Solitary Bees - Buglife Blog - Buglife
• Conservation Volunteering at Prawle Point with Buglife - Buglife Blog - Buglife
• Going on a Bee Hunt - Filming the last bees of Cornwall - Buglife Blog - Buglife
• Première mention de Nomada numida Lepeletier 1841 (Apoidea - Apidae - Nomadini) pour la France continentale