Stag beetle

Habitat:

Very well rotted, damp timbers, usually hardwoods such as elm or oak, often in contact with damp masonry.

Damage characteristics:

Very large, irregular tunnels, up to 20 mm in diameter, and cavities, partially filled with coarse fibrous powder.

Insect characteristics and location:

Adults are rarely found in association with damage.

Larva are very large, up to 50 mm, curved, pale cream. They have three pairs of jointed legs.