Carpenter bees are a species of bee that despite their name do not actually eat wood. Carpenter bees do use wood for their nesting site, excavating chambers within the wood for such a purpose. They rarely can cause great damage to the wood they live in and are valuable assets in nature since they pollinate a number of flower and tree species. Belonging to the genus Xylocopa, the species known as Xylocopa virginica is the one most often referred to as the carpenter bee.
The typical carpenter bee looks like a bumble bee in some respects, however, they lack the yellow hairs on their abdomen and the large "pollen baskets" on the rear legs that bumblebees possess. Carpenter bees are large, about three-quarters of an inch to an entire inch long. The thorax has hairs that are a bright orange, white or yellow, and the insect has a sheen that is almost metallic in nature. The upper abdomen is black and shiny, and a female carpenter bee has a black head as opposed to the male, which does have some white markings on his. The carpenter bee also has dense hairs on its hind legs.
Unlike the majority of bee species, the carpenter bee is a solitary insect. It will not live in colonies, instead opting to pair up with a mate and live in an excavated home. The male carpenter bee does not have a stinger and does not live long after mating. These bees will spend the winter in their nest within a piece of wood and emerge in April or May to mate. Carpenter bees only mate once a year. The females are the ones that build a new nest, using their jaws to make an opening in the wood that looks perfectly rounded and then chewing out a 6-inch tunnel at the rate of an inch every six days. If a carpenter bee has an option it will almost always chew out and enlarge an older nest rather than create a new one. When old nests are constantly reused then there can be some damage to the wood.
Once a suitable home, called a gallery, has been created, the female carpenter bee that has been fertilised will lay its eggs in small brood cells specially made just for that purpose. As many as 10 brood cells will be constructed by the female in one nest. The female dies shortly after completing these tasks, which are her primary function. The larvae will consume a small ball of pollen and regurgitated flower nectar provided by the female and grow, coming out in the late summer weeks as an adult.
New adult bees
The entire process of growing from an egg into an adult for the carpenter bee takes about 7 weeks. The temperature plays an important role in this development, with warmer weather speeding things up. The new adults will stay within their gallery for weeks before chewing out through the wall of wood pulp that the female had put up after laying her eggs in the chamber. By the latter days of August the new adult carpenter bees are outside of the gallery, collecting pollen, which will be stored for the winter months in whatever empty galleries they can find. During the winter the bee will hibernate before emerging in the spring to mate.
The carpenter bee prefers to nest in softwoods such as cedar, fir and pine. They can be found in such places as fence posts, roof eaves, telephone poles, ceilings of porches, shingles, siding and even in lawn furniture. The males have been known to dive bomb humans that invade their territory, but since they do not have a stinger they are harmless. The female carpenter bee is not aggressive and will sting only if handled or severely provoked to do so.