Carpenter Bees

What do carpenter bees look like?

  • Color: yellow and black.
  • Size: 1/2 to 1-inch length.
  • Carpenter Bees look similar to bumblebees except that they have a bare (i.e., no hairs), shiny black abdomen compared to bumblebees which have a hairy abdomen with some yellow markings. 

What do carpenter bees do? 

  • The adults overwinter in galleries, emerging in the spring in order to mate.
  • Females prepare nests by excavating new sites or, more frequently, by cleaning out and expanding existing tunnels.
  • Six to eight brood cells or galleries are constructed in each tunnel.
  • Bee larvae develop during the summer and emerge (typically) in late summer, as adults 30 to 40 days later.
  • Carpenter bees create a single generation per year.

What kind of damage occurs from carpenter bees?  

  • Carpenter bees bore strikingly symmetrical holes into wood from 3/8 to 1/2 inch in diameter.  Each tunnel created is initially approximately six inches long but in subsequent years, might be extended to more than ten feet.
  • Male carpenter bees seem intimidating and aggressive but quite harmless since they lack stingers.
  • Females sting if handled or threatened.

What should I look for?  

  • Entry holes in well-lit and sheltered areas, e.g., headers, roof eaves, porch ceilings, fascia boards, decks, doors, and window sills.
  • Soft wood, e.g., California redwood, cedar, white pine, and poplar, is preferred for building nests. 
  • Untreated surfaces (like the backside of fascia, soffits or underside of low porch railings (that haven’t been painted or stained) and where access exists.

Should I kill carpenter bees?  

  • While carpenter bees are bees and considered pollinators, they are solitary bees that do not live in massive colonies like honey bees.  Therefore, there is minimal environmental harm done as a result of killing nuisance carpenter bees and despite their typically gentle nature, they cause significant and costly damage to impacted wood surfaces.

How do I control or kill carpenter bees?

  • Infested lumber should be removed and replaced with preservative-treated wood.
  • Wood should be painted or varnished in order to discourage bees from boring into it as carpenter bees are averse to freshly painted or stained surfaces.
  • Repellant insecticides can be fan-sprayed and applied to target surfaces to repel bees for a period of 30-45 days.  Thus, follow-up treatments are generally necessary.
  • Dust preparations or foam insecticide applications can be made at the site where new galleries exist and wood putty/caulking can be applied to repair damage. 

The most significant mechanism for controlling carpenter bees is to have an action plan developed by Innotech Pest Management’s founder—Dr. Richard Kramer, Ph.D. and Board Certified Entomologist and State of Florida certified applicator. By taking the guess-work and risk out of treatment, we can stay ahead of carpenter bee problems by pre-planning spring-fall applications and mitigate the risk or extent of damage to your home, trim fixtures or other natural wood apertures of your home.