INJURY: Carpenter bees bore into wood to make a home for the young. Bees may drill a large number of 1/2 Inch diameter holes (in the case of XyIocopa virginica, a common species In the Northeast) in preferred sites. Often the same nesting sites are used year after year, and the same tunnels used.
Nail holes, exposed saw cuts and unpainted wood are attractive nesting sites to these insects. Porches, garages, shed ceilings and trim, railings, roof overhangs and outdoor wooden furniture are common nesting sites.
Continued borings may weaken wooden structures and the yellow sawdust and waste materials may stain cars, clothing or furniture.

DESCRIPTION: Carpenter bees are large black and yellow insects about one inch long that closely resemble bumblebees. The thorax is covered with yellowish hairs and the abdomen is a shiny black without hairs.
The males are territorial and in the spring they often guard the potential nest sites. They discourage intruders by hovering or darting at any moving thing that ventures into the nesting area. This can create a 'human annoyance' factor and it is one that often startles and concerns the homeowner.

LIFE HISTORY: Carpenter bees nest in dry wood and occasionally hollow stems. They overwinter as juvenile adults in the tunnels from the previous year. Those that survive the winter mate In the spring (April to June) and then begin nesting activities. They often refurbish old tunnels in preference to boring new ones. The tunnel may be a foot or more in length. The eggs are placed in cells in a tunnel constructed by the bee. In each cell the female places nectar and pollen she has gathered from flowers as provisions for the young. The larvae hatch and feed on the pollen and nectar and then pass through the pupal stage. New adults emerge before cold weather sets in during the early fall.
The female carpenter bee, like many other bees, can sting but it is uncommon for her to do so, and the males do not sting.

MANAGEMENT: Well painted finished structures are a determent to carpenter bees. When tunnels are found, treatment with an insecticide and sealing of the tunnel is recommended. Wasp, hornet and bee aerosol sprays are effective and easy to use. The material should be applied after dark on a cool evening (when the bees are less active) to the tunnel entrances and along exposed surfaces. A few days after application, if no activity is observed, the holes should be plugged deeply with putty or caulking compound. If the tunnels are plugged without first killing the insects, carpenter bees trapped inside will bore new openings.

6/72 Prepared by: Carolyn Klass and Edgar M. Raffensperger
Senior Extension Associate Department of Entomology
2/89 Revised Cornell University

The above has been reproduced with the permission of Cornell Cooperative Extension of Suffolk County. The information contained herein is believed to be from reliable sources, but has not been verified by any employees of Ocean-Beach.com

Revised: November 09, 2002.