Eastern carpenter bee (Xylocopa virginica) is perhaps one of the most widely-recognized bees in our region. Males’ bossy attitude and females’ penchant for chewing into wooden decks makes them difficult to ignore. Note black glossy abdomen to separate from bumble bee queens at a glance. Human-disturbed environments suit carpenter bees quite well – so long as dead wood (or exposed untreated timber) is available, there are few places you won’t find them.
Active throughout the growing season (March-October); one new generation per year, but individuals may overwinter (so adults from multiple generations fly each year, though the generation to which these adults belong is possible to ascertain in the field).
Common and widespread, from Virginia north to southern New Hampshire, western Vermont (Burlington area), and Toronto.
Size >> honey bee (as large as many bumble bee queens)
Females are large like males, but with completely dark face and normal-sized eyes; often hold wings out when foraging
Males have massive bulging eyes; yellowish clypeus and paraocular areas make distinctive squarish pale spot on the face below the antennae; thorax mustard-pale with a conspicuous black circle in the middle, and first abdominal segment also covered in pale hair; legs and remaining abdominal segments dark; “smoky”, lightly-darkened wings
Bumble bee (Bombus spp.) queens can be of similar size, but have a less glossy abdomen (matte/luster quality), always lack yellow on the face.
Megachile sculpturalis has a more elongate/cylindrical body shape, rough textured abdomen, and (in females) presence of scopal hairs beneath the abdomen rather than on rear legs.
Females excavate nesting cavities in solid dead wood – everywhere from standing snags to wooden porches. Nesting galleries are reused year after year, simply extended by the new tenants to accommodate new nests. This species exhibits both solitary and social nesting behavior – up to five females may use the same nest. Often, most foraging and reproduction in social nests is done by a single dominant female, while subordinate females mainly act to guard the nest (and may eventually leave to become dominant females at other nests). Females that do not reproduce in their first spring/summer may overwinter again to reproduce the following year.
X. virginica is a broad generalist that visits many different flowers over the course of the season. This species frequently engages in nectar robbing, using its mandibles to puncture holes in the base of flowers in order to access nectar (and generally bypassing the flower’s reproductive structures).
The large, dark bee fly Xenox tigrinus is a common parasitoid of Xylocopa nests. In recent years, Megachile sculpturalis has been recorded usurping X. virginica nestsing cavities.
Balduf, W. V. 1962. Life of the carpenter bee, Xylocopa virginica (Linn.)(Xylocopidae, Hymenoptera). Ann. Ent. Soc. Amer. 55: 263-271.
Gerling, D., & Hermann, H. R. 1978. Biology and mating behavior of Xylocopa virginica L.(Hymenoptera, Anthophoridae). Behav. Ecol. Sociobiol., 3: 99-111.
Laport, R. G., & Minckley, R. L. 2012. Occupation of active Xylocopa virginica nests by the recently invasive Megachile sculpturalis in upstate New York. J. Kans. Entomol. Soc., 85: 384-386.
Page last updated:
February 14, 2023