Woodboring
insects
Woodworm
Identifying Woodworm is a specialist job, and being able to tell if the Woodworm is active (alive) or it
is an old dead infestation is also very important.
Woodworm is a collective name for several different species of wood boring insects. Many insect species are able to
use wood as a food source or as a home. In doing so they can cause serious damage to timber by tunneling into
trees, felled logs or wet, decaying timber, But worse, a small number, mostly beetles, are able to attack timber in
the more or less dry conditions found in our buildings. These beetles are referred to as "woodworm" because it is
during the larval or 'worm' stage that they bore and eat into the wood. Most insects will be identified by the
damage they have left behind, it is quite rare to see the insects themselves on the timber. It is however quite
normal to find dead beetles (esp common furniture beetle) on window sills as they are attracted to light. A common
misconception is that the beetle bores its way into the timber, the hole that we see is usually a flight hole where
the mature beetle has left the timber. There are many insects that bore into timber, I have listed here the
categories that cause the more serious damage to UK property, some of these affect timbers in many
countries.
The common furniture beetle
anobium punctatum
 
The most commonly found woodworm is the Common furniture beetle Damage is identifiable from tiny holes
in the surface of wood. These holes are in fact emergence holes meaning that the adult beetle has emerged from and
left the timber.
The beetle lays its eggs on the timber, the eggs hatch as grubs into the timber and these grubs burrow and tunnel
about within the timber. With active woodworm there is a scattering of tiny dust piles on the timber. These are
called frass. Structural weakening is possible and if any doubt you should have an expert opinion. This beetle
tends to be more prevalent in moist timbers, In older houses for example, where the floor joists are near the
ground and ventilation may have been blocked. Treatment can be bought from most Diy stores in the form of a spray
or liquid preservative, however you should bear in mind that the beetle has exited via the holes so treating the
holes it is a bit like bolting the stable door after the horse has ran. Also to be considered is the fact that you
will not have a written guarantee, which is usually a requirement for a sale. Remember you are probably dealing
with hazardous chemicals, and you should observe applicable health and safety regulations.
Building Societies will generally insist on another opinion from a specialist company if a guarantee is not present
or any structural timber has been affected.
House Longhorn Beetle
hylotrupes bajulus
 
The house longhorn beetle larva attacks the sapwood of dried softwoods. Whilst this pest is found both in South
Africa, North and South America and many continental European countries, in England it is mainly confined to
certain districts in Surrey and Berkshire where it has caused serious damage to structural timbers.
The beetle is slightly flattened, measures from 10-20mm in length and is brown or black. The head and first body
segments are thickly covered with gray hairs except for smooth central line and two black protuberances on either
side of the central line on the upper surface. On each wing cover, the gray hairs are grouped in four patches which
may form two transverse bands. Males are usually smaller than females. White spindle-shaped eggs 2mm long are laid
in cracks and crevices in the wood. Each female beetle may lay up to 200 eggs and larvae may hatch in about two
weeks. After crawling on the wood surface they start boring into the timber. The larva is fleshly bodied white grub
and when fully grown may be 32mm long. The duration of the larval stage may vary from 3-11 years. The damage caused
in softwood sapwood during this lengthy larval stage may be considerable.
Woodboring weevil
Pentarthrum huttoni and
Euophryum confine
Weevils have distinct snouts, from which spring the antennae or feelers. There are two species of Weevil which
are found in timbers, they have no individual popular names. They are small, dark brown or black beetles, about 3mm
in length, and are easily distinguished by their pronounced snouts.
The two wood-boring Weevils are almost always found in timber which is damp or infected with fungus - usually Wet
Rot. It is not unusual to find hundreds of adult Weevils crawling about on the surface of the rotten wood.
Weevils tend to consume the soft portions of the timber (sapwood) before the harder portions, giving attacked wood
a peculiar appearance. In contrast to other wood-boring beetles, both the adult Weevils and the grub bore. Exit
holes are very small, often oval with ragged edges.
The life-cycle is less than one year
If you would like to learn more about woodworm, how to
treat/get rid them and identify damage they cause -
look here Dealing with Woodworm
Ptilinus beetle
Ptilinus pectinicornis
The Ptilinus beetle is a fairly distinctive insect in that it has a visible antennae in a comb or sawlike
pattern (depending on which sex) this beetle can live in a limited range of european hardwoods such as beech, elm,
and maple. Damage is often caused during storage of these timbers and can be found in furniture manufactured from
them. The adult is 4-6mm long and produces a cream coloured bore dust that is talc like, can be found on or around
damaged timber May to July.
Powderpost beetle
Lyctus brunneus
Found worldwide, this insect gets its name from the damage it causes, often reducing the sapwood of susceptible
timber to a fine, powdery dust within a few years. The only common species in Britain is Lyctus brunneus, which
belongs to the family Lyctidae and was imported many years ago from North America. Lyctus damage is restricted to
"wide-pored" hardwoods with a high starch content, such as ash, elm and oak. Softwoods such as pine and spruce are
not at risk from these beetles.
The Deathwatch beetle
Xestobium rufovillosum.
Deathwatch Beetle is common throughout the South of England. Northern parts are not usually affected except
where timbers have been imported. This beetle attacks large hardwood timbers such as Elm and Oak. The beetle,
having started in hardwoods, may move across to neighbouring softwoods. This beetle prefers damp conditions and
even better when there is some kind of fungal decay or "wet rot" in the timbers. The beetle needs these conditions
to develop rapidly. Treatment can be done in the form of a paste, a spray on application or a paint on
preservative. If you think you have Deathwatch Beetle, It is strongly recommended that you call in a specialist, If
you would like a free no obligation inspection and some friendly advice click the Free Inspection link above
If you would like to learn more about woodworm, how to
treat/get rid them and identify damage they cause -
look here Dealing with Woodworm
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