Woodworm Species

Woodworm are actually the larvae of wood boring beetles.  There are several species of wood boring beetles in Ireland. Some are more prolific than others and each have variations in lifecycle, preferred woods they infest and extent of damage they can cause. The Common Furniture beetle is the most widespread however House Longhorn and Powder Post beetles can also infest timbers.

With time, these wood boring insects will greatly reduce the strength of the infected wood. Infestations often go unseen - as the main damage is caused inside the timber for several years before adult beetles emerge through 'exit' or 'flight' holes.

Common Furniture Beetle

(Anobium punctatum)

Much damage caused by wood boring beetles in buildings, can be attributed to the Common Furniture beetle. Its natural habitat is the broken branches of trees and areas where the tree bark has been removed.

Appearance

Adult beetle is 3 – 4mm in length.

Life Cycle

Larva will live for 3 - 5 years boring through timber before emerging to breed.

Habits

  • They actively fly in warm sunny weather.
  • Within homes and other buildings the furniture beetle is an exceedingly common pest.
  • Despite its name this beetle can invade more than just furniture.
  • Infestations can damage decorative woodwork, musical instruments, wooden tools and on a more serious scale wood flooring, joinery and structural timbers.
  • These wood boring beetles consume hardwoods and softwoods.

House Longhorn Beetle

(Hylotrupes bajulus)

Although originating in Europe this pest now has a worldwide distribution. Within the Ireland the House Longhorn Beetle is mainly established in the South. 

Appearance

  • Adult beetle is 8 – 25mm in length.
  • Black/brown colour with greyish hairs and 2 black spots on thorax which resemble eyes.

Life Cycle

  • Larvae tunnel between 3 to 11 years before emerging.

Habits

  • Flight holes between 3mm and 7mm.
  • Infests seasoned and partly seasoned softwoods; pine, spruce and fir most susceptible.
  • It is frequently timbers used in the roof space that are infested.
  • Damage can often be severe in timbers around the chimney area. The larvae produce large amounts of bore-dust (or frass) containing cylindrical pellets. Sometimes this is visible in the 'blistered' appearance of the surface wood.  
  • Longhorn beetles will fly freely in hot, sunny weather which enables them to spread an infestation from one building to the next.

Powder Post Beetle

(Lyctus brunneus)

One species of Powder Post Beetle is commonly found in Ireland. This beetle infests hardwoods such as Oak, Ash, Elm, Walnut, Sycamore, Sweet Chestnut and African Mahogany. It attacks these wide-pored hardwoods because the female beetle is able to fit her eggs into these pores. Timbers such as Beech, Birch and Horse Chestnut have pores which are too small and are therefore rarely attacked by the Powder Post Beetle.

Appearance

  • Adult beetle 4 – 7mm in length.
  • Red/brown in colour.

Life Cycle

  • Adult beetles usually appear in the summer months, but in heated premises they can be found throughout the year.
  • The larvae gradually reduce the infested timber, just leaving a thin veneer of wood on the surface.

Habits

  • Emerging adults make pin-hole sized openings 1 to 2 mm in size, often called 'shot holes’.
  • Whole lifecycle is completed in about one year.
  • Primary pest of timber yards.
  • Given enough time, wood will be reduced to a mass of fine powder that crumble to the touch, hence the name 'powder post'.