The Carpenter Bee, of the genus Xylocopa in the sub-family Xylocopinae, is a large type of bee available worldwide. There are some 500 species of Carpenter Bee in 31 subgenera.
Their name comes from the fact that nearly all kinds build their nests in burrows in dead wood, bamboo, or structural timbers. The exception would be those in the subgenus Proxylocopa which nest in the ground. Members of the related tribe Ceratinini are sometimes referred to as “small carpenter bees”.
The bee is traditionally solitary, though some have simple social nests in which mothers and daughters may cohabit.
Carpenter Bee Behavior
Even solitary species tend to be gregarious, and often several will nest near each other.
When females cohabit, there may be a division of labor among them. In these instances, one female may spend most of her time as a guard within the nest, motionless and near the entrance, while other females forage for provisions. What an interesting household.
The bee makes nests by tunneling int the wood, vibrating their bodies as they rasp their mandibles against the wood. Furthermore, the nests may be found on the underside of a beam, bench, or tree limb.
Each nest will have a single way in which may have many adjacent tunnels. The entrance is often a perfectly circular hole measuring approximately 0.63 in (16 mm) in diameter.
Carpenter Bee Constructs
The Carpenter Bee does not eat wood. They discard the bits of wood or re-use particles to build partitions between cells.
The tunnel functions as a nursery for brood and storage for the pollen/nectar upon which the brood feeds. The provision masses of some kinds are among the most complex in shape of any group of bees.
Most bees fill their brood cells with a soupy mass, and others form simple pollen-masses. This is not the case with the Carpenter Bee.
In contrast, this bee will form highly elongated and carefully sculpted masses that have several projections which keep the bulk of the mass from coming into contact with the cell walls. These walls sometimes resemble an irregular caltrop.
Carpenter Bee Mating
The eggs are very large relative to the size of the female and are some of the largest eggs of any kind of insect.
Two very different mating systems appear to be common:
- Species in which the males have large eyes are characterized by a system where the males either search for females by patrolling, or by hovering and waiting for passing ones, whom they then pursue.
- In the other type of mating system, the males often have very small heads, but there is a large, hypertrophied glandular reservoir in the mesosoma, which releases pheromones into the air behind the male while it flies or hovers. The pheromone advertises the presence of the male.