The term “wood bee” commonly describes the Carpenter Bee, belonging to the genus Xylocopa. Despite their name and drilling behavior, these large insects do not consume wood as a primary food source. Like other bee species, they are herbivores, relying entirely on floral resources for nutrition. Their diet consists of pollen and nectar, which fuel their active lifestyle.
The Adult Diet of Carpenter Bees
Adult carpenter bees eat nectar, which provides the carbohydrates necessary for high-energy flight and drilling activities. They also require pollen, a protein-rich substance that supports muscle maintenance and reproductive health, especially for egg-laying females. These bees are generalist foragers, visiting a wide variety of flowers to collect provisions.
Nectar Robbing
Their foraging behavior includes “nectar robbing.” Carpenter bees use their strong mandibles to pierce the side or base of a flower’s corolla tube. This allows them to access nectar directly, bypassing the flower’s opening. They effectively steal the sugary liquid without making contact with the reproductive parts or aiding in pollination. This unconventional method helps them conserve energy and collect food quickly.
Why They Bore Into Wood (If Not for Food)
Carpenter bees bore into wood for architectural reasons, specifically to create a nest for their offspring. A female uses her powerful mandibles to excavate a perfectly circular entrance hole, typically a half-inch in diameter, into soft, unfinished, or weathered wood. She does not ingest the material; instead, she pushes the chewed fragments out as sawdust, or frass.
The entrance hole penetrates one to two inches deep before the female turns at a right angle. She then tunnels parallel to the wood grain, creating a long, hollow chamber called a gallery, which can extend six to twelve inches. This gallery acts as a protected nursery environment, insulated against predators and the elements. The wood functions as a structural material for shelter and a secure nesting site.
Provisioning the Next Generation
The food collected by the adult female is stockpiled to nourish her developing young. Once the wooden gallery is complete, the female prepares individual chambers, or brood cells, within the tunnel. She collects a mixture of pollen and regurgitated nectar, which she kneads into a dense, yellowish paste known as a pollen loaf or “bee bread.”
This pollen loaf is a nutrient-dense meal placed at the rear of a brood cell. She lays a single egg upon this provision, then seals the chamber with a partition made from chewed wood pulp and saliva. She repeats this process, lining the gallery with a series of provisioned chambers. This ensures the next generation has the necessary protein and energy to develop from larva to adult before emerging.