Adults are roughly 8–11 mm long.
Fine-art photographic collection
Osmia brevicornis
A solitary bee whose entire brood can fail when its host flowers open only six days too early or too late.
About this species
Osmia brevicornis(Fabricius, 1798)
Information reviewed15 July 2026
Osmia brevicornis is a European mason bee specialised on pollen from the cabbage family. Its unusually narrow diet and distinctive nest provisioning make it an important model for measuring how climate-driven flowering shifts affect wild bees.
Taxonomy
Animalia · Arthropoda · Insecta · Hymenoptera · Megachilidae · Osmia
Accepted taxon. · checked 2026-07-15
Central and southern Europe into western AsiaBroad range and selected reference localities — not a complete occurrence map.
Central and southern Europe into western Asia
Warm open country, field margins and places with cavities near abundant Brassicaceae.
Spring-active, synchronised with flowering mustards and related plants.
Pollen almost exclusively from Brassicaceae; adults also drink nectar.
Solitary; each female constructs and provisions her own nest.
What makes this species remarkable?
Unlike the usual mason-bee design of one sealed cell per offspring, a female may place several eggs along one continuous mass of pollen provision inside a cavity.
Experimental mistiming by only three days reduced brood production; a six-day mismatch between bee emergence and host flowering caused near-total reproductive failure.
Because females collect pollen from such a narrow plant family, the species has become a powerful living test of pesticide exposure and climate mismatch in oilseed-rape landscapes.
Sources and scientific references
- GBIF — taxon record/search for Osmia brevicornis
- Catalogue of Life — taxon search for Osmia brevicornis
- Peer-reviewed study of nest architecture and unpartitioned provisions
- Journal of Animal Ecology — experimental phenological mismatch in Osmia brevicornis
- Open-access pesticide-risk model using Osmia brevicornis