A Case of Mistaken Identity

By Robert Seay, U of A Division of Agriculture

First posted on 05-09-2008

At first, you may think you have bumblebees zipping around near your porch, deck or carport. It’s a simple case of mistaken identity! Because of other similarities, as well as their black and yellow coloring, the carpenter bee is easily mistaken for the more ill-tempered bumblebee.

The situation can actually be worse since the carpenter bee, as the name implies, will bore into exposed, unpainted wood structures, resulting in a greater problem than a mere bumblebee sting. Their one-half inch diameter tunnels are then partitioned into individual brood chambers.

Carpenter bees are solitary, which means they don’t nest as a colony or hive. But once they hang out their shingle, a resident population of individual bees boring individual holes will gradually develop. This repetitious boring can create 12-inch tunnels in the lumber, resulting in a weakened post, rafter or joist.

Their best character trait is one of non-aggression since the male bee can’t sting, and you would probably have to catch and hold a female bee before experiencing a sting. When a nesting site is approached, the male has a habit of hovering around, zipping back and forth trying to repel the intruder, which is as much aggression as they express.

As kids, my brothers and I would take wood slats, stand around an abundantly bee populated barn and take batting practice. The bees seemed to get caught up in the game and would continue to buzz back and forth, daring us to swing away. The only risk was in getting smacked by a wild swing from another wood slat.

Control is actually simple since a coat of paint on exposed wood members seems to deter their boring. By exposed, I mean any structure that is open to partial light. I’ve never seen carpenter bees bore into wood members inside an enclosed structure. Treated lumber may not provide much advantage either since I’ve noted carpenter bee tunnels in this product.

Another option is to remember that carpenter bees go to roost, so to speak. Once a hole is located, wait until the late evening and stuff it with an insecticide treated cotton ball and seal with a dab of putty. It would be great if all nuisance insects could be handled this easily! Til’ next week!

For more information about carpenter bees or other insects, contact your county extension agent. The Cooperative Extension Service is part of the U of A Division of Agriculture.