Why should you understand the life cycle of a carpenter bee? The most important step to prevent carpenter bees from nesting in your home is being aware of when their season starts. Being proactive to their arrival, rather than reactive to the destruction, is the key to carpenter bee treatment.
After hibernation, adult carpenter bees emerge from their nests in the springtime1. Depending on where you live, it can be as early as late February for the southern states and as late as the end of May for northern states. To avoid the guessing game, you should anticipate the wood bees as soon as the weather turns from winter to spring. This is the time when the Best Bee Trap should be hung up around your home.
When the carpenter bees first emerge, they generally mate within a few weeks2. During this time they gather food and search for the male or female they will nest with. Carpenter bees are solitary bees, so while several young adults may emerge from the same nest, this does not mean they will continue to live together. Typically a carpenter bee male and carpenter bee female will create their own nest together. At the most, one nest will house a few carpenter bee siblings.
Once the wood bees have found their mate and round up their needed nourishment, it is time for nest construction. The female is the lead engineer in this endeavor. She will pick the spot and carve out the entire nest tunnel and create a “gallery” to lay eggs; using her mandibles, the female carpenter bee spends about six days to “drill” about an inch. A typical gallery is about four to six inches long3. The male carpenter bee’s sole job is to protect their staked-out territory from other carpenter bees and predators. If you have ever noticed a carpenter bee dive-bombing your head when you’ve gotten close to a nest, it is without a doubt the male. The female will spend all of her time in the construction of the nest and producing the young.
Into the summer months the carpenter bees continue to build their nests and produce their young. The inner tunnel chambers are quite elaborate, as the female carpenter bee may build on a previous season’s nest. Galleries as long as ten feet have been found4. Once the adult female and male have finished their task of creating offspring and protecting them in the nests, the adult parents will naturally die inside the nest. As larvae and pupae, the offspring remain in the nests inside their brood chambers, which protect them until they develop into adults and can fly and feed on their own5.
Carpenter Bee Larvae inside their brood chambers of a nest.
In August and September, new carpenter bee adults emerge from their nests to feed before they overwinter6. This is essentially a second season for the carpenter bee traps. During this time it is likely many of the young adult bees will find their way to the traps in search for an easy and safe home.
Although males don’t cause the damage that females do, it is important you catch any who are looking to find a home in your home. Carpenter bees pick their nests every year by finding the easiest solution possible, and are attracted to pre-existing nests or potential holes that could turn into nests. Be sure to identify and repair carpenter bee wood damage to help prevent structural problems in the future.
- Susan C. Jones, “Carpenter Bees,” fact sheet HYG-2074, July 3, 2017, Ohioline, Ohio State University Extension, https://ohioline.osu.edu/factsheet/hyg-2074.
- “Carpenter Bees,” Oklahoma State University Extension, accessed May 22, 2023, https://extension.okstate.edu/programs/digital-diagnostics/insects-and-arthropods/carpenter-bees-xylocopa-sp/.
- Jones, “Carpenter Bees.”
- “Carpenter Bees,” Oklahoma State University Extension.
- “Carpenter Bees,” University of California Statewide IPM Program, June 2014, https://ipm.ucanr.edu/PMG/PESTNOTES/pn7417.html.
- Richard Houseman, “Carpenter Bees,” October 2004, University of Missouri Extension, https://extension.missouri.edu/publications/g7424.