The symptoms are often visible at the height of the first branches. According to the current knowledge, the base of the trunk and branches with a diameter lower than 1 cm, are not attacked.

The symptoms are:

• circular holes (diameter 10 to 13 mm) ALB the exit holes of the adults (in our Region some native insects can produce exit holes in the wood, which are, however, of irregular shape and/or different size);
• multiple oviposition pits: are depressed funnel-shaped cavities (with serrated and ovoid edge and with a 10-15 mm diameter) excavated by the female by means of her mandibles. Then the female introducing the ovipositor into the pit, lays an egg under the bark;
• sap oozing from oviposition pits;
• sawdust more or less fine (depending on the age of the larvae producing it), piled up in the infested branch junctions or on the ground;
• adult feeding damages Adults of ALB feed themselves of twigs and leaf petioles evidently eroding the bark tissues.