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Consultation: Non-native control of Dryocosmus kuriphilus

Defra are seeking views from stakeholders on whether Torymus sinensis should be released into England to suppress populations of Dryocosmus kuriphilus (oriental chestnut gall wasp).

Dryocosmus kuriphilus is native to China and has since spread into Japan, the Republic of Korea, Nepal, USA, and many countries in Europe. It was first discovered in the UK in June 2015 in Kent, and as of March 2020, has been detected in over 140 locations in rural and urban areas in South-East England. Galls produced by the wasp impede shoot and flower development, which negatively impacts on the quality of coppiced timber. The galls also reduce tree vigour by reducing leaf area, photosynthesis and tree biomass. Torymus sinensis, a parasitoid wasp native to China, has been very successful in reducing numbers of D. kuriphilus in Japan, the USA and Italy, and has been released in many other European countries. Fera Science Ltd has carried out an assessment of the wasp’s safety for release in England.

Further information can be found in the risk analysis as well as the letter seeking your views.

Please send any responses to by 16 November 2020.