Experience with Dryocosmus kuriphilus Yasumatsu eradication measures in Slovenia*

Abstract

After causing damage in Asia and the USA, Dryocosmus kuriphilus Yasumatsu recently established in Europe on Castanea. The first outbreak in Europe occurred at a C. sativa nursery for production of plants for planting in Cuneo (Piemonte, Italy) in 2002. The Piemonte official service notified Slovenia that a consignment originating from an infested nursery was sold to Slovenia. Prompt phytosanitary action was taken in Slovenia in 2005 in order to trace back plants from this consignment and prevent establishment of the pest. In the period 2006–2009, intensive surveys of forests and fruit production areas showed absence of the pest in the majority of the Slovenian territory, including the demarcated area from 2005. An earlier introduction of infested plants from Cuneo in January 2004 remained undiscovered until 2007. Despite the radical measure of eliminating the infested orchard and removing infested Castanea trees in the forest bordering this orchard, the pest was not eradicated in this outbreak area. Individual infested trees in the forest were confirmed at a distance of up to 10–34 km in 2008, and a further 15 km in 2009. The results of annual surveys, eradication campaigns based on generic contingency elements and the change of strategy after the finding of infested forests are presented.