Carpenter bees are often observed near wooden structures. Their presence frequently leads to questions about their diet and potential for damage. While known for their wood-boring activities, there is a common misunderstanding regarding what they actually consume. These insects play a role in ecosystems, differing significantly from other wood-destroying pests in their feeding habits.
Primary Food Sources
Carpenter bees are primarily herbivores, and like many other bee species, they sustain themselves by consuming nectar and pollen. Nectar, a sugary liquid produced by flowering plants, provides these bees with the carbohydrates necessary for energy, enabling their flight and foraging activities. Pollen, on the other hand, offers a rich source of proteins, lipids, vitamins, and minerals, which are crucial for their growth, development, and reproduction.
Carpenter bees possess a specialized proboscis, a tongue-like mouthpart, which allows them to access nectar from various flower shapes. In some instances, particularly with tubular flowers, carpenter bees exhibit “nectar robbing.” They use their mandibles to pierce the flower’s base, “stealing” nectar without entering the flower or facilitating pollination. This provides sustenance but bypasses typical plant-pollinator interaction. For their offspring, female carpenter bees create “bee bread,” a mixture of collected pollen and regurgitated nectar, which serves as the primary food source for developing larvae within their nests.
Wood Boring for Nests, Not Food
A widespread misconception is that carpenter bees eat wood, similar to termites. Their association with wood stems from their nesting behavior, as female carpenter bees bore into woody materials to create tunnels and chambers for laying eggs and rearing their young. This excavation is purely for habitat construction, not for nutritional intake.
Female carpenter bees utilize their mandibles to chew through wood, creating perfectly circular entry holes, typically about half an inch in diameter. These entry holes extend a short distance into the wood before turning at a right angle, following the wood grain to create a gallery or tunnel. These tunnels can range from 6 to 12 inches long, and some can extend up to 10 feet with repeated use over generations. The wood shavings produced during this process are discarded outside the nest, often accumulating in small piles below the entrance. Carpenter bees prefer unpainted, untreated, and weathered softwoods such as pine, cedar, redwood, or cypress for their nests, though they can bore into harder woods if necessary.
The tunnels serve as protected nurseries where the female bee provisions individual cells with bee bread and lays a single egg in each, sealing it off with wood pulp and saliva. While their tunneling can cause structural damage over many years and with repeated infestations, it is distinctly different from the wood-eating habits of pests like termites.