Situation of Dryocosmus kuriphilus in France
As reported in the EPPO RS 2007/086, Dryocosmus kuriphilus (Hymenoptera: Cynipidae – EPPO A2 List) was observed for the first time in France in 2005. The first detection was made at Saint-Dalmas-Valdéblore (Alpes-Maritimes, Provence-Alpes-Côte d’Azur region) on a small number of chestnut trees (Castanea sativa) but was successfully eradicated. Another outbreak was detected in 2007 in the Roya valley close to the infested area in Italy (see also EPPO RS 2007/086). It is considered that this outbreak corresponds to the natural spread of the pest from the nearby infested Italian area (outbreak in Cuneo, Piemonte region). Intensive surveys will continue in 2008 and phytosanitary measures are being taken to limit the spread of the insect, but its eradication seems difficult.
In July 2007, galls were observed in a lot of 10 chestnut trees during a phytosanitary inspection in a nursery located in Haute-Garonne (Midi-Pyrénées region). Laboratory analysis confirmed the identity of the pest and it was noted that galls presented numerous exit holes, thus suggesting that adults had emerged and may have spread to other trees in the nursery or its vicinity. This infested lot had been originally produced by a nursery in Brescia (Lombardia) and then sent to a Spanish nursery for 11 months before being imported into France. However, it is noted that in Spain there were no chestnut trees growing in the vicinity of the nursery. All infested trees were destroyed in August 2007. All movements of chestnut plants are prohibited for a minimum period of 3 years within a delimited zone of 70 686 ha (quarantine area plus a buffer zone of 15 km radius around the infested nursery). In conclusion, two outbreaks have been detected in France in 2007 and placed under official control.
The pest status of Dryocosmus kuriphilus in France is officially declared as follows: Present, only in some areas, under official control.
NPPO of France, 2008-02.