Maarten de Groot
Fig. 1. Adult of Cossus cossus
Fig. 2. Larva of Cossus cossus
Fig. 3. Pupa of Cossus cossus
Fig. 4. Exit holes cause by Cossus cossus
Fig. 5. Galleries of Cossus cossus inside the tree
Large moth (wingspan: 68-96 mm). wings are grey brown with a wavy pattern. Caterpillars are large (max 10 cm long) and are reddish. The head and patches behind the head are black. The caterpillar first is hibernating under the bark and later makes large tunnels in the wood. The pupae is 45mm long and brown. The attacked trees can be recognized by the fermenting liquid at the tree base. The development time is 2 to 3 years.
Attack different deciduous tree species, but has a preference for poplar (Populus sp.), Willow (Salix sp.), oak (Quercus sp.) and black alder (Alnus sp.). The larvae feeds in the wood, the species can hibernate in the litter layer.
Occurs abundantly in all countries in the REFOCuS area (Austria, Croatia, Hungary, Serbia and Slovenia).
Larvae are feeding on the wood which can kill the trees. Although it is never found in large numbers.
The damage can be confused with other wood boring insects like Cerambycid beetles. However, the larva is typical. The adults are very large, and are difficult to confused with other species.