Dryocosmus kuriphilus found again in the Netherlands
The NPPO of the Netherlands recently informed the EPPO Secretariat that Dryocosmus kuriphilus (Hymenoptera: Cynipidae – EPPO A2 List) has been found for the second time on its territory. The pest was initially reported by a member of the public. Typical galls were detected on 9 trees of Castanea sativa at 5 locations (public and private gardens) in the municipality of Aalten which is located close to the German border. The identity of the pest was confirmed in 2015-06-19 on the basis of its morphological characteristics. Because several galls were lignified, it is estimated that trees have been infested since 2013 at least. The origin of this new outbreak is unknown but natural spread from nearby infested areas in Germany might have taken place. It is recalled that D. kuriphilus was detected for the first time in the Netherlands in July 2010, in another part of the country (municipality of Boskoop). At that time, D. kuriphilus was detected on 5 chestnut trees imported from Italy, on which 173 galls and 2 living adult females could be observed. Infested trees were destroyed and after 3 years of specific surveillance without any further findings, this first outbreak was declared eradicated in October 2013 (EPPO RS 2013/220). Because the EU emergency measures against D. kuriphilus were repealed in 2014, no particular phytosanitary measures will be taken in the Netherlands.
The pest status of Dryocosmus kuriphilus in the Netherlands is officially declared as: Present, in specific parts of the area where host plants are grown.
Sources
NPPO of the Netherlands (2015-06).
NVWA website. Pest Reporting. Insects.