Goat moth

( Latin: Cossus cossus )

From time to time one finds remarkably large circular holes in timber, particularly if there are willows or poplars in the vicinity. These holes are always in the surface timber of structures such as doors and window frames, and they are made by goat moth larvae. The female lays her eggs in crevices of the bark of various deciduous trees, particularly willow and poplar, but sometimes also in fruit trees. The larvae live and feed in the wood for 2-3 years and when fully grown they sometimes leave the tree they have been living in and seek a suitable place for pupation. This usually happens in the autumn when the larvae may be up to 10 cm long, and they may choose any soft timber to provide them with protection. They metamorphose into moths in the following summer.