The sound or appearance of UK deathwatch beetles (Xestobium rufovillosum) seems able to instill an unjustified level of fear in building owners.

The name, almost certainly a contributory factor in this fear, probably derives from past outbreaks of plague, when an increase in audible insect noise would coincide with flea activity and consequent increased sickness levels. Both carers (with heightened senses) and afflicted (in initial stages tired but unable to sleep) would presumably have been subjected to watch-like ticking against a silent night while they contemplated heaven or hell. This nightmare scenario was enhanced by various commentators and writers, not least Edgar Allan Poe, where, in the ‘Tell Tale Heart’, a sound, assumed by the protagonist to be the beating of his dismembered victim’s heart below the floor, is thought by some to be a lesser deathwatch beetle in the wall (see below).

John E Reilly wrote a very good article, printed in 1969 on the use of the deathwatch tag in (english language) literature – principally by Poe (the subject of the article) – but also by others including Addison and Thoreau whose work predates that of Poe – and by Keats, a contemporary of Poes’. Read it here.

(Update 10.03.14 – I came across this poem published in 1725 by Jonathan Swift – Wood An insect which  pre dates the work of Keats .

The only trouble, John E Reilly points out, is that the UK deathwatch doesn’t sound like a ticking watch. The tag ‘deathwatch’ has, rather unhelpfully, been attributed to more than one species of insect which produce noise audible to the human ear. It is probable the death watches of past literary note do not in fact refer to the wood borer X. rufovillosum (the beetle often associated with historic and usually superficial damage to hardwoods in buildings), but to the book lice,  a species of the order Psocoptera that doesn’t feed on wood.  The (very) prolonged and much quieter metronomic ticking produced by this species of lice would have been much more likely to sound like the Reaper’s watch than the off-time grouped taps (generally 6 – 8 in number) produced by X. Rufovillosum.  

The deathwatch beetle at issue here is one of only two (both being anobiids, the other being furniture beetle or woodworm – Anobium punctatum) able to produce damaging re infestations of building timber – given the right conditions. If the building has been reasonably well maintained, damage is likely to be historic, with only outer sapwood edges and exposed beam ends affected locally. Significant structural biological damage to the heartwood margins of building timbers occurs only through chemical modification of the natural biocides present in the wood by fungi. Therefore any wood borers emerging from seriously damaged structural timber are a symptom of the problem rather than the cause.
It is also important to appreciate timing and event sequence with these anobiids, where an emerging adult would have been laid as an egg 5 to 10 years previous (approximately half this in the case of furniture beetle).

See Deathwatch Gothica part II – the German connection.