Eastern Carpenter Bee
pollinator profile: Eastern Carpenter Bee
The Eastern carpenter bee – Xylocopa virginica is native to the eastern U.S. and has 3 subspecies within its range. This large, but gentle bee is often seen nectaring from flowers near wooded areas, particularly conifer forests – its preferred nesting habitat.
- Eastern Carpenter Bee, Common Carpenter Bee
- Eastern U.S. & southern Ontario, Canada
- Early Spring – Fall; Both males & females overwinter in the tunnels they originally emerged from.
- Nectar from a variety of flowers.
- Forests and adjacent areas with flowering plants.
- This species will often rob nectar from flowers by chewing into the flower near the base.
- High beneficial value to pollination. Low/moderate pest status when nests are built in man-made structures.
Although Eastern carpenter bees resemble bumble bees, they can be visibly distinguished by their shiny, bluish black abdomens. Females also have a much broader head than bumble bees.
Male carpenter bees can be distinguished from females by the off-white/yellow cuticle on their face. Males will often defend and guard their territory around mating & nesting sites against other male carpenter bees, yet neither sex is known to act aggressively towards humans. Females do have the ability to sting, but will only do so if severely threatened.
Carpenter bees get their name from their nest building behavior. Females construct nests by chewing a series of tunnels into wood. Eggs are laid within these tunnels and are provisioned with pollen and nectar for the developing larvae to feed on once the eggs hatch. The female offspring will often reuse and/or modify the same tunnels for their own nests. If a new nest is constructed, it is often nearby the existing nest.
Urbanization has replaced much of the preferred carpenter bee nesting habitat (wooded areas with tree snags and fallen logs) with man-made wooden structures. These bees have quickly adapted to nesting in wooden siding, eaves, door frames, railings, fence posts and telephone poles. Although carpenter bees rarely cause structural damage, they can cause damage to the wood itself over time. Contact your local extension office for information on management if you suspect damage by carpenter bees.
Why are there holes in my flowers? Carpenter bees have mouth parts capable of chewing into wood, this also gives carpenter bees the ability to chew into flower buds or the base of blossoms (corollas), taking nectar without aiding in pollination of the plant. This is called ‘nectar robbing’. Despite this occasional nectar robbing behavior, Eastern carpenter bees are regarded as important pollinators.
Eastern carpenter bees overwinter as adults in the tunnels that they originally emerged from. Once the weather warms in the spring, they will immediately begin mating. The males will die soon after and the females will begin constructing a new nest or modifying an existing nest. The new generation will emerge as adults in late summer. These adults will spend the rest of the season feeding in preparation for hibernation. Providing late-season, flowering native plants in the landscape will help ensure these gentle giants survive the winter.
These bees really are gentle giants… The male in the above photos spent nearly 24 hours foraging on the Black Snakeroot, despite my frequent intrusions with the camera, and slumbered peacefully alongside a Common Eastern bumble bee male throughout the night.