Xylocopa virginica
Eastern carpenter bees resemble bumblebees. They have large, rounded bodies that are black with yellow hairs. Their abdomens are black with a purplish tint, hairless, and shiny. Male eastern carpenter bees have a white spot on their face, but females have entirely black faces. Females can sting, while males can not. Larvae are whitish in color. (Grissell, 2017)
Eastern carpenter bees (Xylocopa virginica) are a Nearctic species found in the eastern, central, and southern parts of the United States. They can be found as far south as Guatemala. Their range stretches from Virginia to Florida, and west to Texas. (Grissell, 2017)
Eastern carpenter bees create their nests in dry coniferous woods, stumps, logs, and other dead trees. Nests can be found in cypress trees, pines trees, and juniper trees. Eastern carpenter bees choose sites to build their nest in places like unpainted wood and wood with no bark. They build nests in well-light areas. Eastern carpenter bees often live in the same spot for generations. (Grissell, 2017)
Eggs of eastern carpenter bees are laid in their own cells in the nest. They hatch about 7-10 days after they are laid. Pupae remain in their cells until they are 20-22 days old. Eastern carpenter bees are able to fly 3-4 days after they emerge from their cells, but they remain in the nest for 2 to 3 weeks. When they are not flying, they spend most of their time in the nests with their siblings. (Gerling and Hermann, 1978)
Male eastern carpenter bees catch females in order to mate with them. They will only pursue female bees in flight. If the female bee lands on something, the male bee will either leave her alone or attempt to pull her into the air. (Gerling and Hermann, 1978)
Female bees may live up to two years, mating in the spring of their first year and nesting in their second. Nesting behavior includes digging nests and gathering supplies. There are often two or three females per nest, but only one digs, gathers supplies, and lays eggs. Male eastern carpenter bees defend the nests in March and April, mate with female bees, and die in the late spring. (Gerling and Hermann, 1978; Grissell, 2017)
Female bees may live up to two years, mating in the spring of their first year and nesting in their second. There are often two or three females per nest, but only one digs, gathers supplies, and lays eggs. Male eastern carpenter bees defend the nests in March and April, mate with female bees, and die in the late spring. (Gerling and Hermann, 1978; Grissell, 2017)
Female eastern carpenter bees gather food, build the nests, and lay eggs. After building their nests, female bees will hunt for pollen and nectar. At the nest, the nectar is vomited out and mixed with pollen. This mixture is used to build the cells in which eggs are laid. Each cell contains one egg and is capped in chewed wood pulp. Female bees repeat this process until they have laid 6-8 eggs. Their daughters may remain in the nest after they become adults. (Gerling and Hermann, 1978)
Female eastern carpenter bees live for up to two years. Adult bees come out from their nests in March after a few warm days have occurred. Young bees leave their cells and nests in June. Males die in the late spring. Newly hatched males will spend the winter with the females in the nest but die in the following spring. (Gerling and Hermann, 1978; Grissell, 2017)
Eastern carpenter bees only leave their nests on warm days. They can be solitary or social, which means they nest alone or in groups. Male eastern carpenter bees are territorial and will defend their nests. (Barrows, 1983; Gerling and Hermann, 1978; Grissell, 2017)
Female eastern carpenter bees are responsible for building nests. A single female will choose a spot to nest, often on dead trees, logs, or stumps. She will begin to chew a hole into the wood. She will create the nesting tunnel, known as a gallery, 15 mm in diameter. Female bees are able to chew about 15 mm of wood per day. If the grain of the wood is vertical, the gallery will be built vertically. Similarly, if the grain of the wood is horizontal, then the gallery will be built horizontally. Completed, newly-built galleries are about 35-45 mm in length. Alternatively, old nesting sites may be expanded upon and reused. They are much longer than new galleries. (Barrows, 1983; Gerling and Hermann, 1978)
They can have territories up to 20 m². (Barrows, 1983; Gerling and Hermann, 1978)
Like other social bees, eastern carpenter bees communicate using touch, vision, chemicals called pheromones, and wing vibrations. Bees communicate about the safety of the nest, where food is, and what they should do. Like other bees, eastern carpenter bees can see ultraviolet light. (Horridge, 2015)
Adults consume nectar from a large variety of flowers, such as the flowers of Virginia bluebells, basils, sage plants, currant bushes, American plums, and beardtongues. Eastern carpenter bees have a unique method of pollinating called "buzz pollination". They use their strong muscles to shake the pollen from the flowers. They may also "rob" flowers that they can not fit into by cutting a slit in the base and taking the nectar. (Barrows, 1983; Buchman, 2020)
Eastern carpenter bees are preyed upon by birds like shrikes and woodpeckers. Small mammals like rodents and invertebrates like big-headed ants will feed on adults and their larvae. (Watmough, 1983)
Eastern carpenter bees pollinate and feed on a lot of flowers. They are preyed upon by many types of birds, mammals, and invertebrates. Male bees are territorial and may chase insects, birds, and nonliving objects that trespass on their territory. (Barrows, 1983; Buchman, 2020)
Eastern carpenter bees can damage wooden structures like homes, railings, fences, and buildings. Their nests may weaken and stain structures. Female bees may sting humans. Male bees may hover and dart towards humans close to their nests. (Buchman, 2020; Gerling and Hermann, 1978)
Eastern carpenter bees are generalist pollinators. They may pollinate a variety of plants, including crop plants. (Gerling and Hermann, 1978)
Deena Hauze (author), Animal Diversity Web Staff.
Barrows, E. 1983. MALE TERRITORIALITY IN THE CARPENTER BEE XYLOCOPA VIRGINICA VIRGINICA. Animal Behaviour, 31(1): 806-813. Accessed June 14, 2020 at https://doi.org/10.1016/S0003-3472(83)80237-1.
Buchman, S. 2020. "Carpenter Bees (Xylocopa spp.)" (On-line). U.S. FOREST SERVICE. Accessed June 16, 2020 at https://www.fs.fed.us/wildflowers/pollinators/pollinator-of-the-month/carpenter_bees.shtml.
Gerling, D., H. Hermann. 1978. Biology and mating behavior of Xylocopa virginica L. (Hymenoptera, Anthophoridae). Behavioral Ecology and Sociobiology, 3(2): 99-111. Accessed June 14, 2020 at https://www.tau.ac.il/lifesci/departments/zoology/members/gerling/documents/30.pdf.
Grissell, E. 2017. "common name: large carpenter bees scientific name: Xylocopa spp. (Insecta: Hymenoptera: Apidae: Xylocopinae)" (On-line). Featured Creatures Entomology & Nematology. Accessed June 14, 2020 at http://entnemdept.ufl.edu/creatures/misc/bees/xylocopa.htm.
Horridge, A. 2015. How bees distinguish colors. Eye Brain, 7: 17-34.
Richards, M. 2011. Colony Social Organisation and Alternative Social Strategies in the Eastern Carpenter Bee, Xylocopa virginica. Journal of Insect Behavior, 25: 399-411. Accessed June 14, 2020 at https://doi.org/10.1007/s10905-011-9265-9.
Watmough, R. 1983. Mortality, Sex Ratio and Fecundity in Natural Populations of Large Carpenter Bees (Xylocopa Spp.). Journal of Animal Ecology, 52(1): 111-125. Accessed June 17, 2020 at https://www.jstor.org/stable/4591?seq=1.