Females are commonly about 7–9 mm long.
Fine-art photographic collection
Lasioglossum costulatum
A bee whose survival depends on finding two rare things together: bellflowers and a bare vertical wall.
About this species
Lasioglossum costulatum(Kriechbaumer, 1873)
Information reviewed15 July 2026
Lasioglossum costulatum is a small European furrow bee specialised on pollen from bellflowers and their relatives. Females excavate nests in firm, sparsely vegetated banks and cliffs.
Taxonomy
Animalia · Arthropoda · Insecta · Hymenoptera · Halictidae · Lasioglossum
Accepted taxon. · checked 2026-07-15
Europe, especially central and southern regionsBroad range and selected reference localities — not a complete occurrence map.
Europe, especially central and southern regions
Warm cliffs, quarries, loess banks and walls near abundant Campanulaceae.
Adults fly mainly in summer, tracking the flowering period of bellflowers.
Nectar from several flowers; pollen collected chiefly from Campanulaceae.
Solitary to communal nesting in aggregations; each female provisions her own brood cells.
What makes this species remarkable?
The female is an extreme pollen specialist: a landscape full of flowers can still be useless if it lacks the bellflower pollen her larvae are built to digest.
It also needs near-vertical bare ground for nesting, creating a two-part habitat requirement that can be broken by either mowing the flowers or allowing the bank to become overgrown.
A single larva requires pollen from many individual blossoms, so the bee’s reproductive output is directly limited by the density and duration of the bellflower display.
Sources and scientific references
- GBIF — taxon record/search for Lasioglossum costulatum
- Catalogue of Life — taxon search for Lasioglossum costulatum
- Peer-reviewed account of habitat requirements of European specialist bees
- Peer-reviewed analysis of pollen requirements in specialist bees
- European Red List of Bees — species assessment framework