This rapid assessment shows: 

Likelihood of entry is: likely with moderate uncertainty. There have only been six putative interceptions of P. quercus group species in the UK, all on Holm oak imported from Italy. It is possible however, that during some stages of its life cycle the pest could have avoided detection. It is also possible that it could have been mistaken for a native phylloxerid. 

Likelihood of establishment is: moderately likely with high uncertainty. We do not know with certainty whether any of the Phylloxera quercus group species are present in the UK. There are also uncertainties regarding their distribution on the continent, therefore it is impossible to make a true assessment of their climatic range. 

Economic impact is expected to be: small with moderate uncertainty. 

Endangered area: the south of England is considered the most endangered area of the UK although P. quercus group species do present a risk to all parts of the UK.

Risk management: Severe infestations may require insecticide treatment, but the pest is often difficult to target. 

In conclusion, there is considerable uncertainty associated with the identity and impact of this pest. Given that it is not known with any degree of certainty whether or not P. quercus group species are established in the UK, and that control measures are in any case often unnecessary, as the damage is largely aesthetic, no statutory action is recommended.