Carpenter Bees
When we think about bees, honey bees and bumblebees most readily come to mind. However, there are 25,000 distinct species of bees around the world classified into 9 broad families; the bees most familiar to us make up only a small percentage of the total. And each species has its own distinct features and behavioral patterns.
Carpenter bees are large and hairy; like honey bees and bumblebees, they belong to the Apidae family, but unlike their honey-producing cousins, carpenter bees are solitary rather than social insects. They are often confused with bumblebees because of their relatively large size, but whereas bumblebees are hairy throughout (including their abdomens), carpenter bees have shiny, black, metallic abdomens. There are some 500 species of carpenter bees; they are distributed worldwide, and nearly all build their nests by burrowing into dead wood, bamboo, or timber. The tunnels that they bore in wood are usually close to the surface, so if they nest in structural timber, the resultant structural damage is slight.
A nest will usually have a single entrance but be composed of several adjacent tunnels; entrances are nearly perfect circles, 16 millimeters in diameter. A tunnel will go straight into the wood for an inch or two, then turn 90 degrees, running parallel to the wood�s surface to create the first tunnel. This tunnel will contain eggs and may extend two feet or longer in length. The bees do not eat the wood they bore through; they use their mandibles for boring, and will either discard the resulting bits of wood or use the scrap wood to build partitions between cells within their nests. The tunnels serve both as quarters for bee eggs and then larvae as well as storage for pollen and nectar, which the bees gather from flowers just as honey bees do.
Females will sometimes live together with their female offspring or their sisters, thus creating small social groups. It has been observed that cohabitating females tend to divide their labor; one female may spend most of her time guarding the nest, while another will forage for provisions. Even carpenter bees who live alone tend to leave near others of their species; they seem to prefer the comfort of occasional company.
Different species of carpenter bees follow different mating patterns. Among some species, males will search out females by patrolling, or hovering near nests, waiting for passing females; the males will then follow in pursuit. Among other species, the male will release pheromones from a glandular reservoir; these pheromones advertise the male�s presence to nearby females, who then make themselves available to the males. Male carpenter bees looking to mate can be quite sociable, approaching humans and other animals. These males are in no way trying to be threatening; they are merely curious!
Both male and female carpenter bees hibernate in their tunnels during the winter months. Mating occurs in the spring, and females lay eggs in the tunnels. Carpenter bee eggs are among the largest in the insect world. The bees will feed their newly hatched larvae through the summer, and the young bees then emerge in August, feeding on nectar through the early months of autumn in preparation for hibernation. The cycle then begins again.
Because they gather nectar, carpenter bees are important pollinators of plants, as are most varieties of bees. Azaleas, daffodils, and pansies are favorites of carpenter bees. Occasionally, however, they will damage flowers by slitting the sides of the flower to get at the nectar deep inside. Males are harmless because they do not have stingers; females are capable of stinging, but they are docile and will not sting unless they�re trapped in clothing or caught in the hand.
Because carpenter bees are docile and perform a service in the pollination of plant life, you can leave them alone. However, if they begin nesting in timbers in your home, obviously you�ll need to get rid of them before they cause structural damage. If you find a hole to a carpenter bee nest, do NOT plug up the hole; the nest likely contains larvae or young bees, and the adult (or adults) will drill their way out, or drill their way back in, creating new holes in your timber. Rather, you should consult with an exterminator regarding the best way to rid yourself of the bees.
