Series editors' preface - Wood Tools

one has proof of active infestation. Exit-holes,
frass and, when possible, larvae or adult
beetles should be examined to identify the
species (Dawson, 1980; Kingsolver, 1988;
Mallis, 1982; Pinniger, 1994; Sutter, 1986).
The probability, severity and rate of attack
by woodworm are influenced by moisture
content, temperature, width of sapwood, resin
content and presence of fungal decay.
Woodworm prefer timber with high moisture
content and comparatively low maximum
temperatures. For this reason they are more
prevalent in temperate regions and less
common in centrally heated accommodation
where they are discouraged by reduced
moisture content of wood. Larvae also prefer
sapwood wood and wood with a low resin
content. They grow more rapidly in wood
decayed by soft and white rots. Appropriate
storage and display conditions therefore play
an important role in preventive conservation.
Avoidance of high moisture levels, clean
secure environments and programmes of
monitoring are key elements of the general
control strategy for insects. When infestation is
suspected the affected objects should be
isolated, and the surrounding objects and
environment should be carefully inspected.
Quarantine can effectively be achieved by
placing the object in a bag, made of polyethylene
or similar material, which can be
securely sealed. For practical purposes,
separate bags may be more secure than a
quarantine room. Sticky-traps placed in an
area of suspected infestation can be helpful in
trapping adult beetles and a pheromone trap
is now available for Anobium. An entomologist
should be consulted when there is doubt
about the insect species. Methods available for
the elimination of an active infestation, including
chemical treatments, freezing and low
oxygen environments, are discussed in
Chapter 6.
Death watch beetle (Xestobium rufovillosum)
A member of the same family (the Anobiidae)
as the common furniture beetle, the death
watch beetle, is well known for the damage it
causes to the woodwork of historic buildings,
especially churches. It is widely distributed in
England, Wales and Ireland but occurs less
frequently in the North and is not recorded in
Scotland. The name is derived from the
Deterioration of wood and wooden structures 299
tapping sound produced by both sexes during
the mating season (between June and March),
a series of six to eight rapid taps repeated at
short intervals.
The life cycle of this beetle is similar to that
of the common furniture beetle but, under
normal conditions, may vary in length from
5–10 years or more largely depending on the
extent of fungal decay in the wood but also
on temperature, moisture content and the
amount of sapwood present. The white, lemon
shaped eggs, usually 40–60 but occasionally
up to 200 in number, are laid between March
and June and normally hatch in about five
weeks. The larvae wander over the surface
before boring deeply into the wood where
they may cause severe damage. When the
larvae are fully grown they change into pupae,
during July and August, and two to three
weeks later the pupae change into beetles
which then remain within the wood until the
following spring. Adult beetles emerge
between March and June through a round
flight hole about 3 mm in diameter. The adult
beetle, the largest of the British Anobiids, is
6–9 mm long, chocolate brown in colour and
covered with patches of short yellow hairs
giving it a variegated appearance which makes
it somewhat difficult to spot on the surface of
old wood (Figure 7.10).
Recent research has demonstrated that,
contrary to previous belief, infestation of wood
by the fungus Donkioporia expansia is not
critical for beetle development although
Figure 7.10 The death watch beetle (Xestobium
rufovillosum) seen from above (© Crown Copyright)