The goat moth is a moth belonging to the cossid millers.
Goat moth (Cossus cossus) is a moth and belongs to the cossid millers (Cossidae).
The goat moth is an inconspicuous gray-brown butterfly and + 35 mm in size. They are quite common in Europe, Asia and Africa. The goat moth likes moist environments and can be seen during the months of May through August. The butterflies lay eggs at the base of the trunk in crevices and between bumps. After two weeks, the caterpillars hatch and bore into the trunk of the tree. They hibernate in groups in the bark of the tree. The caterpillars remain in the trunk for two to three years until they reach adulthood. An adult caterpillar is about 10 cm long, has a shiny black head and is red on top. During their years in the trunk, they have drilled many tunnels, slowing the tree’s growth. The many tunnels weaken the branches, which easily break off in storms.
Sawdust at the base of the trunk, large oval holes and a vinegar smell betray the presence of the caterpillars.
The adult caterpillars pupate in spring in a cocoon of sawdust in a borehole.
Control
Difficult to control; once the caterpillars are in the trunk, removal is almost impossible.
Prevention
Cover cut damage to the trunk with wound balm. Destroy infested trees; it is best to do so before early May so that the caterpillars will pupate. Plant less susceptible species.
