oak processionary moth

Oak Processionary Moth (OPM) is a relatively new pest to the UK, with several confirmed outbreaks now identified outside of West London.

Since 2006, OPM infestations have occurred entirely around London and surrounding counties. Although OPM specimens have previously been identified in Leeds and Sheffield, follow-up surveys suggest no viable breeding populations were established.

In June 2019, BALI was alerted by the Animal and Plant Health Agency (APHA) and Defra that further cases of OPM had been identified by the Plant Health Service outside of the Core Zone, affecting counties in the Protected Zones including Warwickshire, Gloucestershire and Hampshire. The incidents involved oak trees imported from the continent, specifically the Netherlands, where OPM is a serious issue.

The most recent map released by the Forestry Commission has shown a slow but steady spread throughout the London boroughs. Members working in or around London should familiarise themselves with this distribution and identification guide, with details available in our OPM document.

BALI members and industry professionals should report any findings of OPM to Tree Alert. You can visit their website here. For more on how to identify OPM, visit The Forest Research website