Nuisance wood borers and seed insects in homes

Quick facts

Some insects may be brought into homes on wood (especially firewood and lumber), seeds and nuts. These insects are a nuisance and do NOT reinfest wood or other products.

  • Most wood-boring insects attack trees or branches that are weak, drought-stricken, diseased, dying or recently dead.
  • They can also be found on trees that have recently been blown down or felled.
  • You may find more nuisance insects in firewood or lumber from damaged trees than in wood from healthy trees.

Damage caused by nuisance wood borers

Nuisance insects are different from powderpost or deathwatch beetles that can reinfest wood and cause extensive damage.

Wood-boring insects tunnel in the wood as they feed.

  • In most cases, the damage is cosmetic and does not affect the structure of the wood.
  • Exit holes that are formed by the adults when they exit the wood can be seen.

Adults have very specific requirements:

  • They lay their eggs only in the bark of green wood.
  • These insects do not lay eggs on logs without bark, dried, sawed, painted or finished wood.

Generally, only a few insects emerge, but sometimes larger numbers are seen.

How do nuisance wood borers get indoors

Nuisance insects are commonly brought in with firewood, but they can also be brought into homes in lumber used for construction or remodeling, decorative items (e.g. wreaths) and furniture.

  • Insects feeding in the tree at the time of harvest remain inside even after the tree is processed into lumber.
  • Some insects continue to develop and complete their life cycle once the lumber is used in the house.
  • This can cause concern to homeowners (but little economic damage) as they bore out of the wood and anything that covers it (e.g., drywall, linoleum, paneling or moldings).
  • These insects will NOT reinfest wood in structures after they have emerged.

Insects can also enter homes inside acorns, nuts or seeds brought in for decoration or as food.

  • The weevils (grubs) crawl out of acorns or nuts and attempt to hide under rugs or other objects.
  • Other nuts or seeds such as hazelnuts, walnuts or honeylocust pods can contain similar insects.

How to get rid of nuisance wood borers

No pesticide treatments are needed to control these nuisance wood borers and seed insects.

  • They are only a temporary nuisance and die or go away on their own.
  • If you see nuisance wood borers and seed insects, physically remove them by hand or with a vacuum.
  • Remember that these insects are harmless to humans and cannot infest seasoned wood.

The best way to manage these pests is to prevent them from coming into homes.

  • To prevent insects from coming in with firewood, leave the wood outside or in an unheated shed or garage.
    • Bring in a small supply as it is needed.
    • This way the wood will be burned before the insects emerge.
  • To prevent them from being imported when remodeling or replacing infested wood, use only kiln-dried lumber.
    • Do not treat logs or lumber with pesticides to control these insects.

Behavior and habits of nuisance wood borers

Pictures of different types of wood-boring insects are provided below. Insects discussed in this section include: longhorned beetles, metallic wood borers, wood wasps, horntails, bark beetles, parasitic wasps and weevils (snout beetles). 

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Jeffrey Hahn, Extension entomologist and John F. Kyhl

Reviewed in 2018

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