That Huge Bumblebee Is Actually a Carpenter Bee

What Is a Carpenter Bee?

Carpenter bees are large (up to an inch long) solitary bees in the genus Xylocopa. There are hundreds of species of these big buzzy fliers around the world, with nine in the United States. These include the Eastern (X. virginica), Southern (X. micans), and California carpenter bees (X. californica).

These bees are found across the U.S. and lower Canada, and are more common in areas with their preferred nesting site: soft woods like pine, redwood, and cedar. A common sign of carpenter bees is a little pile of sawdust beneath perfectly round holes excavated in wood, in both trees and man-made structures.

Eastern carpenter bees have a robust body and a shiny black abdomen, and their upper body (thorax) is covered in yellow hairs. Females have black faces, while males have lighter facial markings.

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Do Carpenter Bees Sting?

Males lack stingers; females are capable of stinging, but only when provoked.

Carpenter Bee vs. Bumblebee

These two insects look very similar, but if you can get a close look, it’s pretty easy to tell them apart. Bumblebees are fuzzy all over their bodies, in yellow and black stripes. Buzzy carpenter bees, on the other hand, have shiny black abdomens, with yellow hairs only on their upper bodies.

Bumblebees are social bees, nesting in large colonies with complex social structures. Carpenter bees are solitary bees, with a single female laying eggs in a nest. Because they don’t have big colonies to defend, these bees tend to be less aggressive overall.

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Carpenter Bee Life Cycle

In the spring, carpenter bees awake from the tunnels where they’ve overwintered. Females seek out good nest sites, looking for existing tunnels or soft wood they can use to make new ones. The female bee chews a perfectly round hole about half an inch across and an inch or two deep. Then, she turns at a sharp right angle and continues the tunnel for another 6 to 12 inches or more. Some bees return to the same nest tunnels generation after generation, making them longer and longer each year.

Next, females stock the nest with “bee bread,” a combination of pollen and nectar. She lays an egg alongside some food, then seals off the half-inch long cell. Females lay a series of eggs, filling their tunnels with these cells.

Meanwhile, male bees patrol the nesting area, buzzing loudly and sometimes dive-bombing passers-by. However, they’re incapable of stinging, so they don’t pose a real threat to humans or pets.

During the summer, the bee larvae hatch and eat the food in their cell. Then they pupate, transforming from a grub-like larva to the familiar fuzzy bee. They eat their way out of the tunnel one at a time, with the bee at the far end emerging last.

Carpenter bees generally live no more than a year, long enough to mate and start the next generation.

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Are Carpenter Bees Pollinators?

Like most bees, these insects feed on nectar and pollen, visiting many flowers every day. They don’t make honey, but they do store the pollen and nectar in their nest cells to feed emerging larvae.

Carpenter bees are important pollinators, carrying pollen from one plant to the next as they travel. But because their bodies are so big and bulky, they can’t fit into smaller, narrower flower necks to reach the nectar.

In these cases, carpenter bees may pierce a hole at the base of the flower, bypassing the pollen-laden stamens to get to the nectar directly—a practice known as nectar robbing. Overall, though, carpenter bees are important pollinators in their native habitats, especially for larger flowers.

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How to Get Rid of Carpenter Bees

Carpenter bees can become a nuisance if they drill into wood siding, decking, and other wooden man-made structures. The damage is mostly cosmetic, but repeated infestations can lead to bigger problems. The small holes on the outside indicate much larger tunnels beneath the surface, which can cause structural damage.

To keep out carpenter bees, paint or seal any exposed wood. Fill holes and cracks and seal them properly, as these bees seek out soft entry points. When possible, choose hardwood for projects, and always maintain your wooden structures well to deter invaders.

For large infestations, consult a professional exterminator.

Carpenter bees are mostly harmless, both to humans and well-maintained wooden structures. They play an important role as pollinators in the ecosystem, so whenever possible, welcome them to your yard rather than trying to eliminate them.

Sources

• University of Maryland Extension – “Carpenter Bees”
• Texas Parks & Wildlife – “Social vs Solitary Bees”
• Best Bee Brothers – “Carpenter Bee Life Cycle: What You Need to Know”