About 3 weeks ago I got a call from a frantic lady who said she was allergic to bees and there was a swarm (a bit early- I thought) in her back yard. I went over to investigate, and found that a colony of bumblebees had moved into a birdhouse she had in her garden. She was very relieved when I offered to remove the birdhouse for the season, and return it after the bees moved out in the fall. This episode got me interested in learning more about bumblebee societies.
There are some interesting similarities and differences between bumblebees and honey bees. They both have one queen per colony, both make wax, both collect pollen and nectar, the queens can lay unfertilized eggs to produce males, and workers live for about 4-5 weeks.
The bumblebee colonies are much smaller, typically 100 to 400 workers. A common nest site is an abandoned rodent burrow in the ground. See sketch of a typical nest from EO Wilsons ‘The Insect Societies’. In the spring, a queen emerges from her hibernation, and must build up several wax structures inside the nest. The first is a honey pot near the entrance. Next is a nesting cup about the size of a pencil eraser. She’ll lay about 8-12 eggs inside this cup. She will feed the growing larvae pollen and nectar she regurgitates. She will spend much of her time lying on top of the structure, incubating the brood. The first adult bees will emerge from the center of the cup, where the warmth was the greatest, approximately 22 days after the egg was laid. This is the first generation of the new colony, and these adults will be smaller than later generations, due to less nourishment. The later generations workers will be almost as big as the #queen. As the first generation is being raised, the #queen will begin construction on other cups, and the structure begins to gain in size. She will not reuse these as brood chambers, rather they will be used as honey or pollen storage, or simply abandoned and built on top of.
...full story with images in the newsletter
Grass Valley, CA