Pseudoanthidium nanum

Distinguished from other Pseudoanthidium species by its notably small size. Separated from the larger and more widespread Anthidium manicatum (European Woolcarder Bee) by its smaller stature and less robust build. Identification to species level often requires examination of male genitalia or detailed morphological analysis.

Found in open, sunny habitats including gardens, meadows, and disturbed areas with suitable nesting substrates and flowering plants. Uses pre-existing cavities for nesting.

Native to Europe and Northern Asia (excluding China); introduced and established in North America. Present across much of Europe, with expanding range in North America following introduction.

Adults active primarily during summer months; specific phenology varies by geographic location.

Females collect plant trichomes (hairs) from leaves and stems to card into nest lining material, the behavior that gives woolcarder bees their common name. Nests in pre-existing cavities such as hollow stems, holes in wood, or artificial bee hotels. Males have been observed defending patches of flowers.

Solitary bee that contributes to pollination of flowering plants. As a cavity-nesting species, it may compete with native cavity-nesting bees for nest sites in areas where it has been introduced.

Occasionally noted in gardens and urban green spaces. Its introduced status in North America has attracted interest from bee researchers monitoring non-native bee establishment.

• Anthidium manicatumLarger European woolcarder bee with more robust build and more extensive pale markings; males are highly territorial and aggressive.
• Pseudoanthidium tenellumAnother small Pseudoanthidium species; separation requires detailed morphological examination.

• BugGuide
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life