Introduction and acclimation of Torymus sinensis in the South of Italy

The Asian Gall Wasp Dryocosmus kuriphilus was accidentally introduced into Italy in 2004. Since then it has spread all over the peninsula where chestnut represents an economic important fruit crop. In 2005 the pest arrived in Campania, where about 40% of Italian and 25% of European chestnut production is concentrated, with devastating consequences. For its control, the exotic parasitoid Torymus sinensis has been introduced from 2009 onward, but so far no survey has been completed to assess its acclimation and, most of all, the level of its activity. In this note data on releasing sites and parasitism rate for the control of D. kuriphilus in Campania are reported. We show that the parasitoid well established in a region characterized by mild winters and warm summers, reaching a good level of presence in several sites of the main area of chestnut production which is concentrated in the provinces of Avellino and Salerno. We confirmed the ability of this parasitoids in moving away from releasing sites following its host. In fact, its presence was recorded in an area where only one release was performed. As expected, the larger releases were followed by higher parasitism rates with some exceptions. The presence and activity of T. sinensis recorded had played a pivotal role in the drastic reduction of D. kuriphilus in Campania within only 5 years from the application of a territorial biocontrol program supported by the local government. Information reported are useful for future AGW managemen