Cossus cossus (Linnaeus, 1758)

Host plants:
The caterpillar lives in the wood (usually just under the bark) of various deciduous trees, especially willows and other softwoods.

Habitat:
Cossus cossus inhabits very various habitats that are characterized by the presence of host plants. Cossus cossus lives in gardens as well as in riparian woodland or wetlands and even in hot, sun-baked quarries with sallow. But a certain peak is reached together with softwoods in river or lake near habitats.

Life cycle:
The caterpillar takes several years to pupation. In the year prior to emergence, the overwintering takes usually place quite fully-grown. They usually leave their tree and create a cocoon in the soil in some distance. I met such a walking larva on a street in N-Portugal in late October 2013.

Remarks:
Cossus cossus is widespread and fairly common, if one looks for the typical feeding scars. Caterpillars can be seen only rarely and usually in the autumn or spring outside of the timber, such as when they crawl across roads and are looking for a pupation or wintering place.