Old House Borer

Physical Characteristics

Adults:

  • Color is black to brownish-black
  • Size is 0.6 to 1 inch.
  • Head and thorax are very hairy.
  • The region behind the head is rounded and has two shiny areas on wither side.
  • The wing covers may be completely black or with patches of gray that form bands.

Larvae:

  • Are cream-colored with dark brown mandibles.
  • Have an enlarged head
  • Size may be up to 1.2 inches long (full-grown).
  • Have three distinct, dark ocelli on each side of the head.

Damage

  • The old house borer is a common pest of buildings in the eastern United States. It is not as damaging as the termite, but is next in number of infestations in the areas where it is found.
  • This beetle prefers well seasoned coniferous wood (pine, spruce, etc.), and the damage to infested wood can be reduced to frass surrounded by a thin veneer of sound wood.
  • They do not attack hardwoods.
  • Exit holes are 1/4 to 3/8 inch in diameter.
  • Tunnels are filled with loosely packed frass.
  • When tunnels are near the surface, the wood may have a blistered appearance.
  • Old house borers generally infest wood that is less than 10 years old (despite its name). Wood older than 10 years may be infested if the conditions are right (high moisture, seasoned softwood).