DEFRA urges action as oak processionary moth found

Landscapers, nurseries, landowners and woodland managers encouraged to check oaks as caterpillars found on imported trees

Oak processionary moth caterpillars (OPM) have been intercepted by Government departments on a number of trees imported from the Netherlands.

Protect the health of your oak trees

Oak processionary moth caterpillars feed on oak leaves and can increase trees’ vulnerability to attack by other pests and diseases, making them less able to withstand weather conditions such as drought and floods.

Anyone who has planted larger oaks (with a girth of 8cm or more at 1.2m above the root collar) imported from the continent should urgently read guidance on how to identify oak processionary moth and report any findings to TreeAlert.


"Oak processionary moth poses a serious threat to the health of our UK oak trees. If you’ve recently planted imported oaks it’s vital you check them now to minimise the spread of this damaging tree pest and protect the health of our nation’s great oaks​."
- Gerard Clover, Head of Plant Health - RHS


Credit: Forestry Commission

Early eradication is vital

Oak processionary moth has become an established pest in parts of London and surrounding areas, but the rest of the country is free from the insect. Action is being taken to eradicate recent findings of OPM in Hampshire, Warwickshire and Gloucestershire, including surveillance, tracing work and destruction of both the caterpillars and infested trees.

The recent cases highlight the need for continued vigilance from industry and government to protect the UK’s trees. An urgent review of import controls on oaks has also been announced.

Credit: Forestry Commission

Report oak processionary moth findings

If you suspect OPM, you should not attempt to destroy or move infected material yourself as they're covered in irritant hairs that can pose a health risk to humans and animals. Instead, report any findings to TreeAlert.

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