EPPO Platform
on PRAs

Rapid Pest Risk Analysis for Acute Oak Decline


This rapid assessment shows: 

Risk for entry is: Unknown for AOD and associated bacteria beyond the UK. With a growing trend to import planting material, particularly large trees for landscape purposes, and roundwood acquired from continental Europe, there is a possibility that bacteria could enter the UK on planting material if the bacterial component was in the latent stage, as well as Agrilus biguttatus because the cryptic nature of the life cycle of the beetle is in the bark and inner tissues. Recent evidence in the UK (S. Denman unpublished) has shown Agrilus biguttatus galleries in trees with a dbh of 12 cm demonstrating that the beetle can colonise young trees. Hilszczanski and Sierpinski (2006) also mention colonisation of younger trees, in this case, 30 year-old trees in Poland were colonised by A. biguttatus. Thus there is a risk of importing both bacteria and Agrilus on trees used for landscaping purposes. Although A. biguttatus is considered native to the UK different genotypes and/or populations of the beetle as larvae and pupating larvae could re-enter the UK via imported trees. 

Risk of establishment is: High Economic impact is expected to be: Very large over the medium term especially in conjunction with effects of other pests and diseases on oak 

Endangered area: Most of the UK – except Scotland at present, but in a changing and warming climate, this country could also be placed at risk. 

Risk management: Practices are suggested to manage the risk (see 15) but most require evaluation to measure their effectiveness.


  • Agrilus biguttatus
  • Brenneria goodwinii
  • Gibbsiella quercinecans


  • Quercus
  • Quercus robur


Type File Size
Pest Risk Analysis Download 1,25MB

PRA Area

  • United Kingdom