Update on the situation of Xylosandrus crassiusculus in Italy
As reported in EPPO RS 2009/054, Xylosandrus crassiusculus (Coleoptera: Scolytidae – EPPO Alert List) was observed for the first time in Europe in 2003. The insect was trapped in Toscana (Italy), during a trial to evaluate different traps for forestry pests. During further studies conducted in Toscana, many specimens of X. crassiusculus were caught in other natural parks and in the harbour of Livorno. As the insect was caught in traps, it was not possible to identify its host plants; however, it is suspected that it may be present in Alnus (alders), Fraxinus (ashes), and Quercus (oaks). No particular damage has been noticed on trees in Toscana. The insect is now considered established and widespread along the Tyrrhenian coast, and eradication does not seem feasible. X. crassiusculus originates from Asia but is also established in some tropical African countries. It is hypothetized that African timber or wood packaging material may have been the pathway of introduction of X. crassiusculus in Toscana.
In 2007, a heavy infestation of X. crassiusculus had also been found on a single carob tree (Ceratonia siliqua) in a private garden (in Alassio) in Liguria. Later, other infested carob trees were found in private gardens in the same area. The infested trees were treated by endotherapy with imidacloprid with successful results. However, it is noted that wild plants may also be infested and act as sources for new infestations in Liguria.
Finally in 2009, specimens of X. crassiusculus were captured at the Marghera harbour near Venezia (Veneto region) but it is not known if established populations are present.
The situation of Xylosandrus crassiusculus in Italy can be described as follows: Present, first detected in 2003, occurring in Liguria (few infested trees, under control), Toscana (many captures but no damage reported so far), Veneto (few captures). Eradication is not considered feasible.
Sources
Personal communication with Franco Finelli, Regional Plant Protection Organization of Emilia-Romagna (IT), 2010-02.