Hylesinus varius (=fraxini)

The ash bark beetle is the most common ash bark pest in Europe. It usually colonizes trunks of medium-aged or young trees. In case of broad-stemmed and older ash trees the beetle lives on thick branches. Its size is 2.5–3.5 mm. The gallery system consists of pairs of 6–10 cm long maternal tunnels. The larval tunnels, 3–6 cm long, are dense and parallel. The larvae push a high amount of wood debris in the form of a whitish powder out of the holes in wood. The larvae usually pupate in sapwood. The adult beetles leave the galleries through exit holes. The adults construct overwintering gallery under the bark. Characteristic galls develop over this place.