Cossus cossus

Goat moth

Description

The female lays eggs in groups of 12-70 into bark cracks, usually in the lower parts of the trunk of older and thicker trees. The little larvae hatch in about 14 days and they feed in the phloem under the bark until the winter. They overwinter in the phloem. In spring they start to feed out large and long galleries. Walls of the galleries are brown to black. They are 15 mm wide and up to 100 cm long. Larvae push out wood chips mixed with frass through a lower opening. The larva is pink to pinkish-brown and has large mandibles on the head. By the autumn of the following year, it reaches the size of 7-10 cm. Attacked trees are easy to be recognized by fermenting liquids at the tree foot. The larva pupates in wood or in the surroundings.

Symptom

Infested trees can be easily identified by the fermenting juice at the base of the trunk. Infested wood has a very characteristic, strong vinegar scent.

Tree Species: Oak, Pear, Apple Tree, Alder, Poplar, Willow

Part of a plant- attacked: Tree trunk

Pest significance: Harmful

Pest Category: Insects

Invasive Species: No

Present in EU: Yes

Seasonal frequency of occurrence