Ant species noxious to cork oak in Sardinia

During the biennium 2009-2010, a survey on the pest status of some ant species was conducted in some cork-oak stands of the North of Sardinia. In the first year, 5 species of arboricolous ants were collected by direct sampling from a number of trees randomly chosen. Although they are not very common species, workers of Camponotus fallax (Nylander, 1856) and Camponotus truncatus (Spinola, 1808) were collected inside little twigs and in other refuges. Crematogaster scutellaris (Olivier, 1792) was the most common species as its presence was detected in every tree. Camponotus vagus (Scopoli, 1763) was observed primarily in old trees and in rotten wood among roots and its pest status has not been seen yet as it rarely builds its nest in productive trees. Serious damages caused by Lasius brunneus (Latreille, 1798) were observed on cork bark of young plants. The ant activity degrades cork, diminishing its market value and makes the extraction of the cork very difficult. As a consequence, in the second year the survey of ant fauna was replicated in the same site by using also pitfall traps and carried out in three other plots. The infestation percentage caused by L. brunneus was estimated as well as the damage on each plant