14 Apr 2008
Attack of the bees! (carpenter bees, that is)
-Billy Skaggs, Hall County Extension Agent
The carpenter bee, Xylocopa virginica (Linnaeus), normally attracts quite a bit of attention in Georgia in the spring of the year. Since it closely resembles the bumble bee, is quite large and attacks wood around homes, it can become an important household and structural pest.
Adult carpenter bees are large, one inch or slightly longer, robust insects. They are blackish in color and possess yellowish hairs mostly on the thorax. The abdomen is shiny black and is bare of hairs on top. This helps distinguish carpenter bees from bumble bees which are similar in size and coloration but bumble bees have yellowish hairs on top of their abdomen.
Carpenter bees burrow into the exposed dry wood of buildings, telephone poles, fence posts, etc. causing an unsightly appearance to the wood and structural weakness. They usually choose wood that is soft and easy to work. They seem to particularly prefer redwood, cypress, cedar, white pine and southern yellow pine. Other woods, even seasoned hardwoods, may be attacked if they have been softened by being unprotected and exposed to the weather for extended periods of time. Bare wood is preferred.
Carpenter bees usually avoid well-painted wood and wood with bark on it. Wood with a stain or light coat of paint can be attacked. Also, wood that has been lightly pressure treated with metallic salts for above ground use, such as for decks, could become infested.
Female carpenter bees seldom sting but when disturbed or handled they can inflect a painful sting. Male carpenter bees cannot sting but they often become aggressive and frighten people when they fly about their heads.
There are at least three methods that could be used to control carpenter bees:
1. Aerosol insecticide sprays labeled for use to control flying insects and bees can be applied directly to carpenter bees. Care should be taken to prevent being stung.
2. Residual applications of insecticides such as permethrin and cyfluthrin sprays can be applied to outdoor wooden surfaces which are being attacked by carpenter bees. Nests or galleries can be treated directly with these insecticides or with others such as carbaryl or deltramethrin dusts that are labeled for carpenter bee control. Carpenter bees will be controlled when they contact the residual insecticide deposit.
Several days following treatment, after carpenter bee activity has ceased, holes can be plugged with dowel rods, plastic wood or with other suitable materials. If carpenter bees continue to attack the wood, additional residual insecticide treatments may be required at weekly or twice weekly intervals.
3. Wood which has been recently painted with oil based or latex paint will not normally be attacked by carpenter bees. Pressure treated wood is often resistant to attacks until it has weather for several years.
|