Carpenter bees: Usually gentle, important pollinators

By Sara Scudier

Ohio certified volunteer naturalist

Editor’s Note: By proclamation, Gov. John Kasich has declared June 16-22 as Pollinator Week in Ohio.

Carpenter bees (genus Xylocopa) are the largest native bees in the United States. They are similar in size to queen bumble bees and are often confused with bumble bees. Many people feel threatened by the size of carpenter bees, but they are gentle creatures. The males are unable to sting, and it is the males that hover in the vicinity of the nest. They will dart after any other flying insect that ventures into their territory, and will approach people who move quickly or wave a hand in the air, hovering a short distance from people and causing unnecessary panic. The female is able to sting, but does so only when extremely provoked.

While carpenter bees are often mistaken for bumble bees, they are much less hairy. They have sparse hairs on their abdomen, which gives them a shiny, metallic appearance. Carpenter bees are found across the United States from Arizona to Florida and north to New York.

They are called carpenter bees because of their habit of excavating wood for their nests. A carpenter bee begins her nest by using her broad, strong jaws to drill a nearly perfectly round entrance hole (about 1/2 inch diameter) into the wood. This hole is usually against the grain of the wood. When the tunnel is about 1 inch deep, the bee turns at right angles to the initial hole and tunnels with the grain of the wood. Bees prefer wood that is greater than 2 inches thick. They do not eat wood. They excavate the tunnels for shelter and as chambers in which to rear their young. Carpenter bees nest in dead but not decayed limbs and trunks of standing trees. They will occasionally create nests in unpainted objects such as doors, windowsills, roof eaves, shingles, telephone poles and wooden fence posts or structural timbers, especially redwood, which can cause them to become a nuisance.

Like bumble bees, they are early morning hunters and can be found on many different species of plants. They are “buzz” pollinators, using their powerful thoracic muscles to vibrate the pollen grains out of the flower’s anthers. Their large body size limits them to large or open-face flowers; they need to be strong enough to support the weight of the bee. Because they are unable to enter the flower opening on long, tubular flowers they use their jaws to chew through the flower and steal the nectar without pollinating the plant. Carpenter bees are, however, excellent pollinators of many plants, including peppers, blackberry, tomato and eggplant.

With a decline in pollinators due to diseases, pests, pesticides, stress and malnutrition, enjoy the presence of these flashy, important pollinators. For more: and

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