Blue Mason Bee
Osmia caerulescens
Osmia caerulescens, the blue mason bee, is a species of solitary bee from the family Megachilidae. It has a Holarctic distribution extending into the Indomalayan region, although its presence in the Nearctic may be due to human-assisted introduction. Source
Where it is now
No records in the last 8 weeks. It may be out of season where the observers and sensors are.
See the Blue Mason Bee on the live map
Arrival dates
The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.
| Region | First arrival | Last arrival | Typical peak | Areas |
|---|---|---|---|---|
| Europe | 13 April 2026 | 13 April 2026 | 27 April 2026 | 1 |
Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.