Critters in the Garden
RSABG Volunteer, Nature Interpreter
When we think of bees most of us imagine the little honeybee, originally a European transplant, gathering nectar in a flower garden or orchard. There are many types of indigenous bees that we rarely notice as they go about their business of foraging for food. One of them is the carpenter bee.
About 500 species of carpenter bee can be found world wide and of those the California carpenter bee, Xylocopa californica, is the one most common here. They get their names from the fact that they build their nests in dead wood or buildings.
Resembling a bumblebee, the carpenter bee is similar in size (about three-quarters inch to an inch) and has similar blue-black coloration. The abdomen is shiny. Males of some species have a white or yellow face, females do not. Carpenter bees have large compound eyes. Males do not have a stinger, but females are capable of stinging although they rarely do unless provoked. Carpenter bees are found in meadows, forests, desert mountains and at sea level. Adults drink nectar. Larva feed on nectar and pollen, often by biting through the base of the flower.
Considered solitary, some species of carpenter bees have simple social nests in which mothers and daughters may cohabit, sharing duties of brood tending and foraging. Often several will nest near each other. Males intent on mating may either search for females by patrolling, or by hovering and waiting for passing females, which they then pursue.
Carpenter bees make nests by boring into dead wood. Because their nests are near the surface, the structural damage is minimal. Their mandibles function as rasps against the wood, making a single entrance which may have adjacent tunnels. They discard the bits of wood or use it to build partitions between cells. In each cell they deposit a large egg, one of the largest among the insects. The eggs hatch in late summer, each waiting in line at the entrance to the nest for its turn to leave.
Next time you are strolling in the Garden on a warm day observe carefully and try to spot a carpenter bee or two out foraging. You may get lucky and find where it enters or leaves its nest in an old tree limb.