Bee id? - Ask Extension
I live in Salem, Oregon and I have a bee house out with 6, 8, and 10 mm straws for Mason Bees. I have been getting a lot of bees that look like small...
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Bee id? #927781
Asked April 07, 2026, 9:27 PM EDT
I live in Salem, Oregon and I have a bee house out with 6, 8, and 10 mm straws for Mason Bees. I have been getting a lot of bees that look like small honey bees using the house. They seem to like all three straw sizes. I am hoping to find out more about them. Can you tell me what they are and how I should care for them?
Thanks,
Rob
Marion County Oregon
Expert Response
Hi Robin,
These are invariably a related mason bee, Osmia cornifrons. If you look carefully you will see two horns on the front of the head that are used to mine mud. These bees were introduced from Japan and are widespread though the Willamette Valley. They are great pollinators like Osmia lignaria. Its very hard to tell them apart at the cocoon stage, so you likely will be dealing with a mixed population from here on in. We do ask that people raising bees in the Willamette Valley with O. cornifrons not ship them outside the region. While they are widespread in the Willamette Valley, we don't want to encourage their further spread.
Best,
Andony
These are invariably a related mason bee, Osmia cornifrons. If you look carefully you will see two horns on the front of the head that are used to mine mud. These bees were introduced from Japan and are widespread though the Willamette Valley. They are great pollinators like Osmia lignaria. Its very hard to tell them apart at the cocoon stage, so you likely will be dealing with a mixed population from here on in. We do ask that people raising bees in the Willamette Valley with O. cornifrons not ship them outside the region. While they are widespread in the Willamette Valley, we don't want to encourage their further spread.
Best,
Andony
