However structural repairs may be necessary if colonies are present year after year in the same timber. Effective control includes prevention, persistence in locating the nesting site and insecticide applications. Description At least twelve species of carpenter bees occur in the United States. Some species become economically important when they nest in sound structural wood. They are metallic blue-black with green or purplish reflections and are covered with orange or bright yellow hair.
Bumblebees have some yellow hair on the top of the abdomen.
Female carpenter bees also have a dense brush of hairs on the hind legs whereas bumblebees have unusually large pollen baskets. Both male and unfertilized female carpenter bees overwinter in nest tunnels constructed the previous summer. May. Mating occurs within a few wecks and nest construction follows immediatcly. The fertilized female often cleans out and reuses an old gallery without further burrowing. She may also lengthen an existing gallery or tunnel into wood to construct an entirely new gallery.