Alert for Caterpillar Pest in Oak Trees

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Press Release from Tandridge District Council

People in parts of northern Surrey, London, West Berkshire and South Buckinghamshire are being reminded to look out for and report caterpillars of the oak processionary moth (OPM), which could be damaging oak trees in the area.

They are also advised to keep away from the caterpillars and their nests, because their hairs can cause itching skin rashes and other health problems and to report sightings to the Forestry Commission.

OPM is a tree pest which was accidentally introduced to England. They feed on oak leaves and in large numbers they can severely defoliate trees and leave them vulnerable to other pests, diseases and drought.

Their tiny hairs contain a protein which can cause itchy skin rashes and, less frequently, eye and throat irritations and breathing difficulties in people and animals. The hairs can be blown on the wind, and left in their nests on and under oak trees.

The greatest risk period is May to July, when the caterpillars are active, although nests should not be touched at any time. The Forestry Commission website has pictures to help identify the pest.

Infested oak trees should be treated by qualified operators under strict controls to ensure it is safe for people, pets, livestock and the environment.

Report OPM sightings to the Forestry Commission, using the Tree Alert online form available from Anyone who cannot use Tree Alert may e-mail or telephone reports to  or 0300 067 4442.

Health advice is available from the “Insects that bite or sting” area of the NHS Choices website,

Anyone pruning or felling oak trees in the affected areas should contact Forestry Commission England’s Tree Health Unit beforehand on  or 0300 067 4442 for advice about safe removal of the material.

Councillor Tony Elias, Chairman of the Community Services Committee, said: “We strongly advise people not to touch or approach the caterpillars or their nests because of the health risks posed by the hairs. Pets and livestock can also be affected and should be kept away as well.”

For more information contact Giuseppina Valenza, Head of Communications, Tandridge District Council on 01883 732704.

WebmasterAlert for Caterpillar Pest in Oak Trees