Carpenter bees
resemble bumblebees in both size and appearance, but are not social
insects. They construct their nests in trees or in frame buildings.
Most of the top of the abdomen of carpenter bees is without hairs and
is shiny black in color. By contrast, the abdomen of bumblebees is fully
clothed with hairs, many of them yellow in color. If you see a number
of large bees hovering near the eaves of the house or drilling in wood,
you have carpenter bees. There is only one species of the large carpenter
bees, Xylocopa virginica, which is encountered in Pennsylvania.
The male bee is unable to sting. It is the male carpenter bee, which
is most often noticed. They hover in the vicinity of the nest and will
dart after any other flying insect that ventures into their territory.
A common behavior of the males is to approach people if they move quickly
or wave a hand in the air. The males may even hover a short distance
from people causing unnecessary panic. The female however, is capable
of stinging but seldom does. She must be extremely provoked (i.e. handled)
before she will sting.
DAMAGE AND CONCERNS
While the
damage to wood from the drilling activities of a single bee is slight,
the subsequent year's broods will expand the tunnel through branching
activities and may cause considerable structural damage. Additionally,
they will commonly defecate on the wall or other item directly below
the opening causing stains.
Carpenter bees do not eat wood. They excavate the tunnels for shelter
and as chambers in which to rear their young. They usually attack unpainted
objects such as doors, windowsills, roof eaves, shingles, railings,
telephone poles, and sometimes wooden lawn furniture.
A carpenter bee begins her nest by drilling 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 to attack wood that is greater
than two inches thick.Young
adult male and female bees hibernate in the tunnels during the winter.
They mate in the spring and set about to clean out and enlarge the old
tunnels or to excavate new ones as brood chambers for their young. Each
chamber is provisioned with a portion of "bee bread", a mixture
of pollen and regurgitated nectar, which serves as food for the larvae.
An egg is deposited on the food supply and each chamber is sealed off.
There are typically 6 to 8 chambers created by the female. The larvae
that hatch from the eggs complete their development and pupate. Newly
developed adult carpenter bees emerge in August, feed on nectar and
return to the tunnels to over-winter.
By Steve
Jacobs, Sr. Extension Associate © The Pennsylvania State University
2003.

Aries
Pest Control, Inc.