Tuesday, November 9, 2010

End of year solitary bee nests

Well it's November now, cold enough to take down my solitary and mason bee nesting blocks and store them in the unheated garage for the winter. There they will be protected from ice, freezing rain, winds, and mice.

My top wooden mason bee nesting block has about 10 tubes that are either partially or completely filled with cocoons and capped with mud...

The middle nesting site consists of two 'cans' of nesting tubes. As you can see, the bees really liked the lower can and filled almost all the 60 tubes with cocoons and mud. They used a few of the tubes in the upper can too, but only after the lower can was basically full. My best guess is that because the morning sun hits the lower can first in the chilly Spring mornings, the bees may have liked that warmth...

The bottom wooden block was specially made with smaller diameter tubes of 1/4"- I was experimenting to see if that would attract the smaller leafcutter bees, which I have read like slightly smaller tubes than the blue orchard bees use. I didn't see much action there this year, but I did put the box up a little late in the season.
However, late in the summer there was one single very small bee who kept coming and going there, and it managed to fill just ONE tube before it disappeared. I noticed the tube was not capped with the usual brown mud. Instead, it was capped by a strange dark black-green mash that seemed like dark green tar. It looked to be a paste made from chewed leaves or vegetation. Because it didn't appear to use any neatly cut leaf pieces, but used a paste instead, I am wondering if it is something different from a leafcutter bee.
I'll be asking around to try to figure out what kind of bee uses this capping. The bee itself was a bit hard to see when it was working- somewhat non-descript and very small and fast moving...but it did look appear to be a bee rather than a wasp. I will be watching this tube very carefully next Spring!...click the picture for a close up view:

In all, I started my first Spring of mason/solitary bees with six bought tubes of blue orchard mason bees....and wound up with two or perhaps three species of solitary bee cocoons, filling between 60-70 tubes.  I estimate each tube has anywhere between 3 and 5 cocoons in it, so that will be around 180 to 350 new little solitary bees emerging next Spring to populate the neighborhood!  :)  I will have to add at least one more nesting box, for sure.  I may try to get a neighbor or two involved.


  1. This is very interesting! I wanted to buy a mason bee tube this year and never got around to doing it. I think it will be a must for next year. My kids would enjoy watching the process.

  2. I tried to attract mason bees last year by putting out a nesting block, but I got nothing. What part of the country do you live in? I am in Massachusetts. Did you have to provide a source of mud (or is there one available)?

    -- Steven
    (my bee blog in case you are interested)