Orange-vented Mason Bee
Osmia leaiana
This record describes Osmia leaiana (species). Recorded family: Megachilidae. Recorded order: Hymenoptera.
Identification and Appearance
10mm females, 6mm males. As with all Osmia species, it has a large box-shaped head (similar in size to the thorax). Females have a dense orange pollen brush under the abdomen. Males lack the pollen brush and are generally dark, often metallic green, with ginger hairs. Eyes are black. The tip of the abdomen is smooth (except for the central indent). The males of O. leaiana and O. caerulescens are very similar. However O. caerulescens males have green eyes (when alive) but these are black in O. leaiana . Also, the tip of tergite 6 is crenulated in caerulescens but smooth in leaiana (except for the central indent). Records should include a photo, or set of photos, showing the key characters. We will accept records identified by a recognised local or national expert, or that have been identified via the BWARS’ Facebook noting the name of the person/organisation identifying the record (e.g. ‘Stuart Roberts, BWARS Facebook’). It uses a wide range of habitats, especially sites with plentiful thistles and knapweeds. It can be frequent in gardens and is one of the species that like to exploit bee hotels. Nests in cavities in dead wood, walls or cliffs. Adults collect pollen exclusively from Asteraceae. Restricted to England and Wales. It is less frequently found than O. caerulescens, but occurs in similar habitats.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Hymenoptera
- Family
- Megachilidae
- Genus
- Osmia
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Habitat
It uses a wide range of habitats, especially sites with plentiful thistles and knapweeds. It can be frequent in gardens and is one of the species that like to exploit bee hotels.
Seasonal Activity
Between May and August.
Diet and Behavior
Life History
Nests in cavities in dead wood, walls or cliffs. Adults collect pollen exclusively from Asteraceae.
Additional species information
Recorded status
Restricted to England and Wales. It is less frequently found than O. caerulescens, but occurs in similar habitats.
About Flies: the wider group
Order-level background for Hymenoptera, the group containing Osmia leaiana. Species-specific details appear above.
Group overview
Hymenoptera includes over 150,000 described species of ants, bees, wasps, and sawflies. Earth harbors approximately 20 quadrillion (20×10^15) ants, with a combined biomass of ~12 megatons of dry carbon - exceeding the combined biomass of all wild birds and mammals (PNAS, 2022).
Ecological role of the group
About 35% of the world's food crops depend on animal pollinators. The chocolate industry, valued at over $100 billion, depends on pollinating flies and midges. Ants are the dominant soil engineers in most terrestrial ecosystems, turning more soil than earthworms in many habitats.
Economic and practical significance of the group
Pollinators contribute $235-577 billion worth of annual global food production (FAO). In the U.S., bee pollination alone benefits crops valued at $18 billion annually, and honey bees are responsible for $5.4 billion in agricultural productivity. Between April 2023-2024, 55.1% of managed honey bee colonies were lost. The U.S. bee population dropped from 5 million to 2.5 million.
Recorded sources for this group: FAO, USDA, EPA, PNAS (2022), US Fish & Wildlife Service. Imported estimates may describe particular regions or reporting periods.
Photos of Orange-vented Mason Bee (8)
Frequently Asked Questions About Orange-vented Mason Bee
What is Orange-vented Mason Bee?
Orange-vented Mason Bee (Osmia leaiana) is a species in the family Megachilidae, within the order Hymenoptera.
How big is Orange-vented Mason Bee?
to the thorax). Females have a dense orange pollen brush under the abdomen. Males lack the pollen brush and are generally dark, often metallic green, with ginger hairs. Eyes are black. The tip of the abdomen is smooth (except for the central indent).
Where is Orange-vented Mason Bee found?
Habitat: It uses a wide range of habitats, especially sites with plentiful thistles and knapweeds. It can be frequent in gardens and is one of the species that like to exploit bee hotels.
When is Orange-vented Mason Bee active?
Orange-vented Mason Bee: seasonal activity - Between May and August..
What is the life cycle of a Orange-vented Mason Bee?
Nests in cavities in dead wood, walls or cliffs. Adults collect pollen exclusively from Asteraceae.