Large carpenter bees and bumble bees are often confused with each other. However, they really are different… so much so that they are in separate subfamilies of bees. Carpenter bees are in the subfamily Xylocopinae while bumble bees are in the subfamily Apinae.
The primary species of large carpenter bee in Ohio is the Eastern Carpenter Bee, Xylocopa virginicais. Bumble bees are in the Bombus genus. According to iNaturalist data, there are nine species of Bombus commonly observed in Ohio. These species vary in size and include (ranked by number of observations):
- Common Eastern Bumble Bee (Bombus impatiens)
- Brown-belted Bumble Bee (Bombus griseocollis)
- Two-spotted Bumble Bee (Bombus bimaculatus)
- Golden Northern Bumble Bee (Bombus fervidus)
- Perplexing Bumble Bee (Bombus perplexus)
- American Bumble Bee (Bombus pensylvanicus)
- Lemon Cuckoo Bumble Bee (Bombus citrinus)
- Black-and-gold Bumble Bee (Bombus auricomus)
- Half-black Bumble Bee (Bombus vagans)
Differences in Appearance
The Common Eastern Bumble Bee (Bombus impatiens) is the bumble bee most likely to be confused with an Eastern Carpenter Bee. An easy way to tell the difference is to look at the bee’s behind (nothing personal!). Eastern Carpenter Bees have a “shiney hiney” while bumble bees bottoms are hairy. Carpenter bees also have larger, hairier heads than bumble bees.
Solitary vs. Social Nesting Behavior
The differences between Carpenter and Bumble Bees go beyond appearance. Carpenter bees are solitary nesters. Individual females dig out tunnels in wood and lay eggs in the tunnel with a separator between the eggs and provisions for them. They are not eating wood but rather digging out wood. This is why sawdust is found around their tunnels. When this tunneling behavior happens in a human structure, Carpenter Bees become viewed as a damaging pest. Once the eggs are laid, the female does not return to tend them.
“Carpenter Bees,” Ohioline, Ohio State University, https://ohioline.osu.edu/factsheet/hyg-2074
Bumble bees are social nesters. The nest is active for a season and within it is a queen, worker bees, and drones. The social structure is actively working to reproduce bees till winter. A new queen bumble bee is the only one surviving through the winter to start a new colony. Bumble bees nest in existing cavities… they do not dig nor bore into wood so they do not cause damage.
Photo: Al Eggenberger, “Bumble Bee Nest,” Iowa State University Extension and Outreach
Small Carpenter Bees
Small Carpenter Bees are in the same subfamily as Large Carpenter Bees. Neither their size nor appearance would let them be confused with bumble bees though. It is more likely that they would be confused with a sweat bee.
However, like their larger cousins, Small Carpenter Bees are solitary nesters and females will hollow out the pith in old plant stems to create a cavity to lay eggs.
BuzzAboutBees.Net
Other Resources
About Bumble Bees, Xerces Society.
Photos by Randy Litchfield unless otherwise noted
© Randy Litchfield, some rights reserved (CC-BY-NC)
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