BEHAVIOR, DIET & DAMAGE

DIET: Contrary to popular belief, Carpenter bees do not eat wood but do feed on plant pollen and nectar.

BEHAVIOR: The female is capable of stinging but seldom does so unless she is provoked or handled. The males do not sting, but they usually make property owners mistakenly interpret protecting their territory for aggression and the possibility of stinging. 

DAMAGE

Large carpenter bees excavate dry, unpainted and weathered wooden objects such as the following:

– doors – window sills – roof eaves – railings – decks – untreated poles – fences – even wooden lawn furniture

One of their favorite items to excavate is the rails and posts of oak split rail fences. They prefer pine, fir, hardwoods like oak and redwood, especially if the wood does not have bark, is unpainted or unfinished. The bees sometimes bore into painted wood, especially if the paint covering is old and weathered.

The Carpenter Bees bore holes called galleries. The Gallery construction is a labor-intensive process that takes a lot of time and energy. As a result, females often prefer to reuse the nests instead of excavating new ones. Refurbished tunnels may increase several feet over several years. When required, females will use their strong mouthparts to chew round nest entrances in flat wood surfaces.

The holes are slightly less than 1/2-inch wide, which is about the diameter of her body and looks much like a carpenter used a 1/2-inch drill to create the opening. The bore hole goes into the wood perpendicular to the wood’s grain for about 1-2 inches and then takes a right angle turn continuing as an excavated gallery (tunnel) that runs about 4-8 inches. The female then partitions off brood cells into linear rows. When finished, she places a food ball (made from pollen and regurgitated nectar) inside a brood cell, lays an egg, and blocks the chamber off with chewed wood pulp. After laying eggs, the female dies. The eggs hatch and become larvae that feed on the food ball until they pupate.

CARPENTER BEE’S LIFE CYCLE & REPRODUCTION

Carpenter bees have four life stages: egg, larval, pupal, and adult stages. It takes about seven weeks for a carpenter bee to reach adulthood, but developmental time may vary depending on temperate or other environmental conditions. Newly developed adults usually remain in their galleries for several weeks and leave their brood cells in April or May.

They mate, feed on pollen and nectar, return to their gallery to overwinter and then emerge the following spring. Carpenter Bees typically have one generation per year in up North, but in southern states like Georgia, they may have two or more generations per year.