Walking around the garden tonight (July 30), I admired the swamp milkweed (Asclepias incarnata) in bloom. Then I noticed a bee on the underside of the flower head; it was an eastern carpenter bee (Xylocopa virginica). I’ve got tons of them this year, and fortunately they are leaving my house, deck, and fence alone for the most part. I’m surrounded by woods including a fair amount of dead trees that I leave out for the fauna.
Then I saw another bee, and then three more – all on the milkweed!
Only female carpenter bees can sting, but you have to grab them to make them go that far. Males have a pale yellow dot on their face. In spring, bees emerge from their nests and mate; then females may use the old nest or excavate a new one and lay eggs, which hatch in August. These babies will overwinter in the same nests and emerge in spring to begin the cycle again.
Carpenter bees are great pollinators of eggplant, tomato, passionflower, and blueberries.
For more information…
Penn State has a great page about the carpenter bee life cycle.
Here’s a scholarly article on using carpenter bees instead of honeybees for commercial crop pollination.