Xestobium

Pronunciation

How to pronounce Xestobium: //zɛsˈtoʊ.bi.əm//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Images

Summary

Xestobium includes the deathwatch beetle, notable for its woodboring larvae that infest ancient timber, particularly in historic buildings. Infestations can lead to structural damage, mostly in lumber affected by fungal decay.

Physical Characteristics

Adult deathwatch beetle is cylindrical measuring on average 6 to 7.5 mm long. The head is largely concealed by a brown thoracic shield, which is dark brown or reddish-brown with patchy felting of yellowish-grey short hairs. The antennae have eleven segments, with the distal three segments enlarged. The larvae are creamy-white with six legs, black jaws, and a swollen thoracic region, growing up to 11 mm long. The eggs are white, sticky, and measure about 0.7 mm long and 0.5 mm wide.

Identification Tips

The presence of wood-boring insects may be indicated by frass (fecal residue) and fresh dust. Recent exit holes often have bright rims, while rims of older holes are dull. The exit holes of deathwatch beetles are 2 to 3 mm in diameter, larger than those produced by the common furniture beetle. The adult beetles can sometimes be found on window sills or glass.

Habitat

The deathwatch beetle's natural habitat is found in dead or decaying hardwood, or, in some cases, coniferous wood, especially when softened by fungal attack.

Distribution

This beetle is found in Europe (including the UK), North America, Corsica, Algeria, and New Caledonia.

Diet

The larvae feed on decayed wood, using enzymes to digest cellulose and hemicellulose in the wood. They require decayed wood as it is easier to chew through than fresh wood.

Life Cycle

In Britain, adults emerge in April to June. Males emerge first; females mate shortly thereafter. Females lay 40 to 80 eggs in crevices in the wood which hatch after about a month. Larvae bore into timber, feeding for 2 to 10 years before pupating and emerging as adults.

Reproduction

Mating occurs in concealed locations, with females laying eggs in crevices in the wood or in holes from emerging beetles. The adults do not feed post-mating and die within a few weeks.

Predators

The steely blue beetle (Korynetes caeruleus) preys on deathwatch beetle larvae.

Ecosystem Role

As wood-borers, larvae play a role in the decomposition of dead wood, although they can weaken structural timbers in buildings.

Economic Impact

Infestation tends to be limited to historic buildings primarily made from old oak wood, causing significant damage in regions like England.

Cultural Significance

The tapping sound of the deathwatch beetle has been associated with omens of death, deeply rooted in literature and folklore.

Collecting Methods

• Light traps

Preservation Methods

• Drying specimens for taxidermy
• Preservation in ethanol or other solutions

Similar Taxa

• Anobium punctatum
• Korynetes caeruleus

Misconceptions

The beetle's tapping sound is often misconceived as a death omen, though the sound is actually a means of communication between beetles.

Tags

• insect
• beetle
• woodborer
• cultural significance
• pest
• Xestobium