The carpenter bee (Xylocopa genus) is named so because it burrows into dead wood or bamboo to make its nest, although one species in the subgenus Proxylocopa, prefers digging tunnels in certain soils. They especially prefer bare, unpainted softwoods like pine, cedar, redwood, and cypress. The body of this enormous genus is black, often with yellow hairs or stripes starting on the chest (thorax) and extending down to the abdomen, and is ½” to 1” long, often living up to three years. People who don’t know much about bees often confuse the carpenter bee with the bumble bee. These bees can live up to three years.
Certain species of the carpenter bee can be found in parts of Asia, India, and Europe. There are two species of the carpenter bee that can be found in the eastern part of the United States. Three other species are more widely found in the West.
The bee makes a nest by tunneling into wood, bamboo, and other hard plant materials. Their bodies vibrate as they scrape their mandibles against the wood. Each nest has a single entrance—a circular hole roughly the size of a dime on the underside of a limb or bench—with multiple tunnels heading away from it. They do not eat the wood particles, but instead use them to build partitions within the nest. The nest is used as a nursery and storage space for the pollen/nectar on which the brood will survive.
Mating occurs in the spring and the female will lay her eggs in late spring or early summer. In relation to the size of the female, her eggs are quite large and some can be the largest eggs among all insects. Late summer into fall, the new adult bees mature. Everyone shelters in the tunnels during the winter until spring.
Males are harmless because they have no stinger, but they will hover and dive-bomb to make you believe they can sting. And while females do have a stinger, they are docile and sting only if handled or provoked. The sting is painful and there will be swelling, but unless you are allergic to bee stings, there is no concern.
A brood of carpenter bees can cause significant damage to wood. If they find a particularly favorable nesting area, they will return year after year. Filling holes and entrances are only temporary solutions to eliminating them and pesticides are only minimally successful. Their nests also attract woodpeckers who, in search of a delightful, sunny afternoon snack of bee larvae, will then cause greater damage in its attempts to reach the nest.
The bee is a highly effective pollinator, especially valuable in the early spring and late fall when there are fewer pollinators at work. They are able to buzz pollinate. Once they land on a flower, they vibrate their back muscles so loudly that the sound energy shakes the plant and releases the pollen from the flower. In North America, eastern carpenter bees pollinate 15% of agricultural crops—especially eggplant and tomato—and are generalist pollinators visiting many types of flowers resulting in biodiversity and ecosystem stability. Despite the damage they cause to wooden structures, they are considered beneficial insects to have around for their pollinating work. The key to controlling the damage is to manage the bees. Providing alternative wood sources in gardens or away from the house, can keep the benefits the carpenter bee provides, without having to sacrifice your home.
Sources: wikipedia.org/wiki/Carpenter_bee; fs.usda.gov/wildflowers/pollinators/pollinator-of-the-month/carpenter_bees.shtml; gardenia.net/guide/carpenter-bee; bernardspest.com; irescuebees.com/do-bees-that-work-as-carpenters-qualify-as.html
Did You Know?
The wings of the carpenter bee are a dark, smoky-tinted color, appearing almost black. But in certain light refraction, the wings will take on a metallic blue-purple or smoky purple sheen. However, wing color is not a defining trait for carpenter bees.
According to a study done at Cambridge in 2004, bees can recognize and differentiate between human faces. They recognize their beekeeper over everyone else.