Carpenter Bee

Actual Size: ½ ” –  1”

Characteristics: Large, black and yellow; shiny hairless abdomen

Legs: 6

Antennae: Yes

Habitat: They do not live in nests. Instead, females bore holes through soft wood to lay eggs in.

Habits:

  • Carpenter bees hibernate in vacant nest tunnels during the winter
  • They tunnel through wood and prefer soft, dry, weathered wood
  • Females possess a stinger while males do not

Carpenter Bees in Iowa

Contrary to popular opinion, carpenter bees do not eat wood. Instead, they get their name from their habit of boring into wood, creating chambers to raise their young. Along with bumble bee queens, carpenter bees are the largest native bees in the United States. Carpenter bees can be found across the United States and are seen here in Iowa frequently. Over a long period of time, carpenter bees can cause damage to structures by excavating tunnels in wood, particularly in lumber that is dry and weathered. Carpenter bees may buzz like saws when constructing nests (hence their name), making it easy to hear when they’re nearby.

Carpenter Bee Habitat

Unlike many bees, carpenter bees are not considered social insects. They create individual nests in trees, eaves or sides of structures. Males and females overwinter in old nest tunnels and emerge in the spring to mate. The mated female selects a suitable piece of wood for nest construction while the male spends most of their time hovering near nest sites. The female excavates a gallery using her mandibles, furnishes her nest with “bee bread” (a mixture of pollen and regurgitated nectar), deposits an egg and closes the cell with chewed wood pulp. If you notice a piles of sawdust accumulating near sources of wood, there may be carpenter bee activity nearby. 

Carpenter Bee Behavior & Threats

For the most part, these bees will leave you alone. Female carpenter bees are not aggressive, but possess a stinger and may sting when threatened. Male carpenter bees, on the other hand, are very aggressive and defense. The good news is that they do not possess a stinger. If you or someone you know is stung by a carpenter bee and is allergic to bee venom, they should seek immediate medical attention.

Although carpenter bees can be helpful pollinators, the main concern with them is that they can cause significant damage to structures. Windowsills, wooden siding, decks, railings, outdoor furniture, and fences can be attacked. While the damage to wood from excavation of individual carpenter bees may be slight, their activity spread out over the years can cause significant damage. For this reason, it’s important to always contact a licensed bee control professional.