Native parasitoids associated with Dryocosmus kuriphilus in Tuscany, Italy

Abstract

The invasive Dryocosmus kuriphilus Yasumatsu (Hymenoptera Cynipidae) is a major pest of Castanea spp. in Asia, the USA and Europe. The aim of this study is to characterize the parasitoid community associated to D. kuriphilus in Tuscany and determine their relative occurrence, before the introduction of the exotic parasitoid Torymus sinensis Kamijo. Ten hymenopteran parasitoids were collected from D. kuriphilus galls. Mesopolobus fasciiventris Westwood is reported for the first time as a D. kuriphilus associate in Italy. Torymus flavipes (Walker) specimens accounted for more than 50% of all collected parasitoids. Facultative hyperparasitoid species were also collected. Furthermore, a higher overall parasitism rate was found on wild chestnut galls (with respect to cultivated ones) and where oak trees were more abundant.