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Oak Processionary Moths

Boroughs and landowners must take steps to prevent and contain the spread of oak processionary moths

  • By London Councils

Oak processionary moth caterpillars defoliate trees and their irritating hairs present a human and animal health risk, threatening the closure of parks and other green spaces. It is classified as a pest under British and European legislation.

Oak processionary moths were first found in west London in 2006. Eradication remains the objective everywhere where outbreaks occur except for west London, where containment is the only realistic option.

Since 2013 an enhanced control programme has been piloted, including surveying, spraying and removal of nests. This is the final year of the £4m Defra funded pilot, which will be evaluated.

Health impacts are rare, but occupational health problems amongst tree workers appear to be increasing.

From October 2014, European legislation recognises the parts of the UK outside of the affected areas as a 'protected zone'.

Landowners, including boroughs, in affected areas must continue to work with the Forestry Commission to survey trees.

Boroughs, landowners and waste operators must continue to avoid moving arisings from oak trees outside the protected boundaries, due to risks of spreading oak processionary moths.

The Forestry Commission has published a Good Practice Guide and a manual for oak tree ownersBoroughs need to make provision for managing oak processionary moths in the core zone, as shown on this map

More information on oak processionary moths, including the life cycle, impact on oak trees and how it can be controlled can be found on the Forestry Commission website