The lone mason bee I saw last week.
Last year I started raising orchard mason bees (Osmia lignaria), which are cute little solitary bees that live in holes in masonry or wood, or in the case of my bees, in paper straws made specially for them. At least, in theory mine live in straws.
Keeping mason bees is a much simpler affair than keeping honey bees. Mostly it’s just providing nesting space (straws or reeds), mud (they use it as dividers between eggs), and pollen during their active period, which is in the spring. After they’ve laid all their eggs or their wings are too tattered to fly, which is around when most fruit trees stop flowering, the adults die, and you put the straws which are now full of eggs and larva somewhere warm and protected from birds, beetles, and mice. Then in the fall, you pop the straws in a refrigerator until a few weeks before the fruit trees begin to bloom in the spring. In the fall, you’d generally also want to open up some of the straws and check for pests, which only takes a few minutes.
Since last year was my first year raising mason bees, I slightly screwed up this process, and when I put the straws inside in mid-summer, I put them in the basement, but I should have put them somewhere warmer. This Spring, I put some of the tubes out in March, and some in April. Until today, I though I may have killed them all, because I had only seen a single bee hanging out around the bee house, and I should have at least 60 cocoons. Usually in the spring, the males emerge first, and hang around the nesting holes until the females emerge, so they can mate with them. Then the females go out and gather pollen and mud, lay eggs on top of piles of pollen, and seal off the eggs with a wall of mud, and then repeat the process until they die a month or two later.
Because I thought I had killed off all my orchard mason bees, and it’s too late to order more this year, I decided to try summer mason bees, Osmia californica. Californica bees are very similar to orchard mason bees, except they emerge later in the year, they use chewed up leaves instead of mud to separate their eggs, and they prefer aster-type flowers. I got my little carton of 20 californica bee cocoons in the mail today from Crown Bees, and I was surprised when I opened it that it smelled distinctly like flowers.
Osmia californica, with my index fingertip for scale.
There was also one little bee that had emerged from his cocoon during shipping that was crawling around in the box, so I carefully slotted the carton into the mason bee house I made last year, and got to watch him crawl out to the roof of the house to sun himself. I started taking photos of him crawling around covered in the pollen that had rubbed off on him as he made his way through the other cocoons, and it didn’t take long to notice that there were some orchard mason bees also flying around near me. I couldn’t figure out why they seemed to be bouncing off the wall next to the bee house, instead of flying into it, so I stood back a few feet in case I was in the way. This is when I realized that they weren’t accidentally missing the bee house- they’re heading for old nail holes in the wall instead. It makes me wonder if the others are either just late to emerge, or are perhaps nesting in my wooden shingles. I’m not sure why they’re shunning my paper tubes, but I’m glad to know they’re not all dead.
This little orchard mason bee is hanging out in old nail holes instead of in the paper straws in the mason bee house. This one looks like like a male to me, so he’s just hanging out, but if I’m wrong and it’s a female, it may be depositing pollen and laying eggs in that hole.
Ha! Crafty buggers.
Michelle,
Nice post, and good luck with the Osmia californica.
From my experience, paper straws are not necessarily the best option—I would say they are one of the poorest options. Paper straws have their advantages, but I have noticed Osmia lignaria generally prefer to nest in more solid and protected living environments, where their offspring is safe from predatorial creatures or weather that can compromise thin walls. They also have an interesting ability to differentiate between a poor nesting site and a suitable nesting site, and are likely to select the latter for their offspring. In a nutshell, they are good realtors—who also happen to be pregnant mothers—and desire to prolong their posterity.
I would very much like your feedback about mason bee ownership. I have a survey link at research.nativebees.com
Kimball, thanks for your input. In your experience what housing option is the first choice of Osmia lignaria? Reeds? Cleanable wood trays? I’ve been going with the easy-tear paper straws from Crown Bees for ease of fall harvesting, but have no particular objection to other housing options, and may need to expand to a second bee house soon.
I’m still working on that problem, and have been doing so for years. Contact me at info@nativebees.com for details and I’ll expand.
We’ve been using the stacking plastic trays with great success – very easy to disinfect and clean. We usually have paper tubes nests in close proximity to see if they will choose the more ‘natural’ material first and so far this has not been the case in over 5 years of observations. http://www.beediverse.com is our local supplier of these stacking nesting boxes. Great blog!
Fascinating! Thank you for this very informative post. I’ve been interested in mason bees for some time now, but just haven’t taken the steps to make it happen.
Michelle, thanks for the Twitter follow. You’re on the right path with spring mason bees… make mistakes, learn from them, and then adjust. Wood trays are best overall as they are cheaper (one time cost), and retain nesting scents. Reeds are most preferred by the bees as it’s very easy to find their hole. More expensive, but easy for the bees to find!
We’re here to help you. Glad you’re raising these bees!
Michelle,
Before I commence, know that Dave and I are both in the Native Bee business. It is in its infancy, but we are making great strides. We are also part of an organization that is trying to better implement the use of Orchard Bees for pollination efforts.
From my observation, many native beekeepers differ in their opinions of what works, and what does not. The fact is, there are “what is known presently to work sufficiently” and “what might work better in the future.” Climactic differences, the pollination needs you have, and bee propagation volume—in my opinion—call for native bee nesting environments that starkly differ. That being said, I suggest you experiment with a variety of different options each year. Eventually, you will prefer one of a few options that best meet your needs. Always keep an open mind when dealing with native bees, but document the successes.
Wood trays certainly yield good results, but these trays also have weaknesses. I disagree with Dave that reeds “are most preferred by the bees,” simply because “it’s very easy to find their hole.” I have experimented with a slew of different nesting types, two of which have exceeded the reeds’ performance.
Dave would agree that I’m slow to make my prototypes available for sale, but they will come about soon enough for you to test and compare. In the interim, I suggest you become your own scientist!
Dear Michelle,
This is a very interesting post about these bees. Please keep us updated on your results!
-Jay