Dryocosmus kuriphilus found in the south of France (Alpes-Maritimes)
The NPPO of France recently informed the EPPO Secretariat about the presence of Dryocosmus kuriphilus (Hymenoptera: Cynipidae – EPPO A2 List) on its territory. The pest had been detected on 2005-07-15, in three galls collected from a single chestnut tree (Castanea sativa) at Saint-Dalmas-Valdéblore (Alpes-Maritimes, Provence-Alpes-Côte d’Azur region). This tree came from a young plantation (established in autumn 2004) consisting of 18 trees which had originally been imported from the area of Cuneo in Italy (where the pest occurs). No galls were observed on these 18 trees or in their vicinity. As a precaution, all trees concerned were burned on the 2005-07-27. Because no further findings were made during intensive surveys, this first outbreak is now considered eradicated.
Within the framework of a surveillance programme for D. kuriphilus initiated since 2005 in the Roya valley close to the infested area in Italy, numerous galls were observed in 2007 on approximately 20 chestnut trees growing near a children’s playground at Saint-Dalmas-de-Tende (Alpes-Maritimes). This village is located 15 km away from the Italian border and near the main road between Cuneo (IT) and Menton (FR). The identity of the pest, D. kuriphilus, was confirmed on 2007-04-26. Delimiting surveys were then conducted in nearby forests (covering an area of 12 x 10 km). D. kuriphilus was detected on 14 sites corresponding to 4 communes (Tende, La Brigue, Fontan and Saorge). The presence of exit holes on dried galls (made the year before) suggested that the pest was already present in this area since summer 2005. It is suspected that the pest was introduced by vehicles, as the main infested areas were found near a car park and a children’s playground. Because D. kuriphilus has now been found in several forestry sites, including old trees, its eradication is not considered feasible. Phytosanitary measures were immediately implemented to limit pest populations and delay further spread. In accordance with EU emergency measures (Commission Decision 2006/464*), a focus zone of 5 km radius and a buffer zone of 10 km radius were delimited around each infested site. No nurseries or garden centres were located within these delimited areas. All movements of plants for planting of C. sativa are prohibited, within or from the delimited areas for a minimum period of 3 years. All chestnut growers or owners have been advised to prune and burn all infested twigs before mid-June (flight period of the insect). Finally, information leaflets are being distributed to chestnut growers or owners (forests, parks and gardens) in all other departments of the Provence-Alpes-Côte d’Azur region. Surveys will continue in 2008 in the Roya valley and research will be carried out on the possible use of a biocontrol agent (Torymus sinensis, Hymenoptera: Torymidae) and resistant chestnut cultivars (e.g. ‘Bouche de Bétizac’).
The situation of Dryocosmus kuriphilus in France can be described as follows: Present, first found in 2005, few locations in the south of France (Alpes-Maritimes), under official control.
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* Commission Decision 2006/464/EC of 27 June 2006 on provisional emergency measures to prevent the introduction into and the spread within the Community of Dryocosmus kuriphilus Yasumatsu
Sources
NPPO of France, 2007-06.