Detection of alien wood boring beetles in Italian ports: A nationwide study

Wood boring beetles are among the most important forest pests causing significant economic damage to forests worldwide. Considering that they may be easily transported in almost all types of woody material they are recognized also as highly successful invasive species. Receiving large amounts of commodities, maritime international ports are the most common points of entry for these species. The aim of this study is to improve our knowledge on the factors affecting the invasion of alien wood boring beetles in ports and their surrounding areas. We focused on Scolytinae, Cerambycidae and Buprestidae. Port size and characteristics of the landscape surrounding the ports, in terms of forest cover and forest composition (conifer vs. broadleaf), were investigated to assess their influence on the occurrence of alien wood boring beetles. From May to September 2012, 15 Italian ports were monitored monthly setting up multi-funnel traps both in ports (3 traps) and their surrounding areas (3 traps). Fourteen (11 Scolytinae and 3 Cerambycidae) out of 81 trapped species were alien to Italy or Europe. The presence of alien species was positively correlated to the amount of imported commodities at port scale, and it was affected by the forest composition of the stands surrounding the ports. Specifically, broadleaf forests presented higher alien species richness in comparison to coniferous forests. On the contrary, forest cover in the landscape positively affected only the occurrence of native species. Finally, the number of both alien and native was higher in forests than in ports. Our results suggest concentrating monitoring efforts in large ports surrounded by mixed broadleaf forests.