A few telephone calls and one Port Gibson-based e-mail this week have prompted today’s column about carpenter bees. I found it interesting that all those individuals first referred to the insects as bumblebees and included some phrase similar to “they’re eating my house up.”

There is no doubt that carpenter bees suffer from a serious identity problem. They do look a lot like bumblebees, but there is a big difference in the biology and habits of these two groups, which aren’t even in the same entomological family. One of the most easily observed physical differences is that the top of the abdomen of a carpenter bee is slick and shiny, while a bumblebee is covered with black, white or yellow hairs.

Most people are probably more concerned about the nesting habits of the bees than with the abdominal appearance. The primary species occurring in Warren County is xylocopa virginica. I suspect that most of the carpenter bees observed have been males searching for a mate and hovering around the eaves, facia boards or window trim of a home. In case you are worried, male carpenter bees are harmless, though their habits sometimes include buzzing and hovering about in mid-air or getting that in-your-face attitude. Males do not sting, however. Females can sting, but seldom will unless they are handled.

While bumblebees usually nest in the ground, carpenter bees tunnel into wood to lay their eggs. The tunnels or galleries will have perfectly round entrance holes, which are about one-half inch in diameter and can be up to 2 feet long. Bare or unpainted or weathered softwoods, such as pine, cypress and cedar, are preferred, but the bees will occasionally bore in other types. Painted or pressure-treated wood is much less susceptible to attack. Carpenter bees tend to congregate around favorable nesting locations, and females will reuse and enlarge old galleries from year to year. Timbers can be weakened by the presence of multiple galleries, and galleries can also allow moisture to enter the wood and speed up decay.

Painting or sealing the wood is the best method of preventing carpenter bee problems. However, there are situations where the rustic look of unpainted wood is preferred. Sometimes it is not practical to paint exposed beams and rafters in barns and storage sheds. When using paint to prevent a carpenter bee attack, it is important for the paint or sealant coat to be thick enough to cover the wood grain. The bees will readily bore through paint as long as they can still “feel” the wood grain.

The most effective way to control carpenter bees with insecticides is to apply small amounts of insecticide dusts with deltamethrin into the galleries. A couple of products commonly available include Terro Ant Dust and Enforcer Fire Ant Killer, which are both labeled for control of bees and wasps. After leaving the treated gallery alone a few days, it is a good idea to then plug the entrance with a wooden dowel coated with carpenter’s glue or wood putty. This will protect against the future use of the old nesting tunnels and reduce the chances of wood decay.

John C. Coccaro is county Extension director. Write to him at 1100-C Grove St., Vicksburg, MS 39180 or call 601-636-5442. E-mail him at jcoccaro@ext.msstate.edu