Deathwatch Beetle

Xestobium rufovillosum

Classification

Pronunciation

How to pronounce Xestobium rufovillosum: //zɛsˈtoʊbiəm ˌruːfoʊvɪˈloʊsəm//

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

Images

Xestobium rufovillosum Schadbild by Mätes II.. Used under a CC BY-SA 3.0 license.
Exit holes of death-watch beetle (Xestobium rufovillosum) - geograph.org.uk - 3129758 by Stefan Czapski . Used under a CC BY-SA 2.0 license.
Xestobium rufovillosum IMG 20220607 152052 by Jens Milner. Used under a CC BY-SA 4.0 license.
Xestobium rufovillosum (Anobiidae) (10136611174) by gbohne from Berlin, Germany. Used under a CC BY-SA 2.0 license.
Iz - Xestobium rufovillosum - 1 by Emőke Dénes. Used under a CC BY-SA 4.0 license.
Xestobium rufovillosum (bonte knaagkever) schade by Rasbak. Used under a CC BY-SA 3.0 license.

Summary

Xestobium rufovillosum, commonly known as the deathwatch beetle, is a woodboring beetle associated with old oak timber and known for its distinctive tapping sound which has cultural significance related to death.

Physical Characteristics

Adults are cylindrical measuring on average 6 to 7.5 mm (0.24 to 0.30 in) long with a brown thoracic shield and elytra that are dark brown or reddish-brown. The larvae are creamy-white with black jaws and grow to about 11 mm (0.4 in) long, notably having a swollen thoracic region and multiple golden setae.

Identification Tips

The presence of frass (fecal residue) and fresh dust near exit holes, which are 2 to 3 mm in diameter, can indicate infestation. Adult deathwatch beetles may be found on window sills and can be attracted to light.

Habitat

Preferred habitat includes decaying hardwoods, particularly oak, that has been softened by fungal decay, often found in old buildings.

Distribution

Native to Europe and adventive in North America (New England, IL). Also found in Corsica, Algeria, and New Caledonia.

Diet

Larvae primarily consume wood, digesting cellulose and hemicellulose using enzymes present in their gut, particularly favoring wood that has been softened by fungal decay.

Life Cycle

The life cycle takes about 2–3 years but can extend up to 10 years. Eggs hatch into larvae, which bore into the timber and feed for several years before pupating.

Reproduction

Mating occurs soon after emergence in concealed locations. Females lay 40 to 80 eggs in crevices in the wood.

Predators

The steely blue beetle (Korynetes caeruleus) is known to predate on deathwatch beetle larvae.

Ecosystem Role

They play a role in the decomposition of wood by breaking down cellulose and hemicellulose in decaying timber.

Economic Impact

Economic damage is significant in historic buildings, particularly those made from old oak wood in England.

Cultural Significance

The tapping sound is associated with death and has inspired various literary references, reflecting superstitions around its presence.

Collecting Methods

  • Light traps to attract adults
  • Inspecting infested wood for frass and exit holes

Preservation Methods

  • Gas fumigation
  • Insecticide injection through drilled holes
  • Ultrasound examination to determine extent of infestation

Evolution

Part of the beetle family Ptinidae, which includes wood-boring beetles and scavengers, this species has been classified under various subfamilies over time.

Similar Taxa

Misconceptions

Traditionally believed to be an omen of death due to its tapping sound, leading to numerous cultural associations and superstitions.

Tags

  • deathwatch beetle
  • Xestobium rufovillosum
  • woodboring beetle
  • cultural significance
  • economic impact