Species of Mason bees in Oregon

Asked February 1, 2020, 1:22 PM EST

My question concerns which source I should use to obtain Mason bee cocoons or whether I should rely on cocoons at all. Perhaps there are enough local Mason bees that I should just start with tubes/houses and rely on native bees to build a population in my area. I originally thought I would use a source in Portland but after watching a YouTube video (Garden Style NW) I am having second thoughts about the source. The presenter in the video said that the Mason bees in the eastern part of Oregon are a different species than those on the west side. My question is should I avoid importing bees (cocoons) from the west side of the state? Would I be introducing an exotic that might be harmful to our local bees? The presenter did say that the two Oregon species will interbreed but is that a good thing? I may be making a mountain out of a mole hill, but I want to be sure I'm doing what is right by the bees. Thanks for your assistance.

Wallowa County Oregon

2 Responses

Hi, OSU Extension has several publications concerning mason bees. The First one is “Nurturing Mason Bees in your Backyard in Western Oregon”. I realize that Wallowa County is not western Oregon, but this publication contains valuable information about mason bee biology. They also published “Megachilid Bees in the Pacific Northwest, an Introduction” which has some of the same information but includes the entire state and other species of native bees. The Oregon Bee Project has a staggering amount of resources listed under the tab bees. These are also worth a look. The final publication from OSU is “Living on the Land: Providing Habitat for Native Pollinators”. This will give you more ideas on how to provide habitat so that bees that are native in your area will be attracted to your landscape and nest there.

It looks like Osmia lignaria or Blue Orchard Mason Bee is native to the entire state. However your location will have locally adapted strains that would be slightly different. The current thought is that it is best to build a native bee beneficial landscape to attract the bees that thrive in your particular region rather than to import them from outside your area. Your local public library might have a copy of the Xerces Society guidebook, “Attracting Native Pollinators”. This useful book has chapters ranging from “Strategies to Help Pollinators” to “Providing Foraging Habitat” to “Pupation and Overwintering Sites”. It is definitely worth reading and I think it will give you confidence that you will be able to provide for masons bees that already live in your area.

Enjoy this new adventure.


Thanks for sharing your time and expertise. Your information is going to make my project much simpler and less daunting.

Have a pleasant day!

D. Bright