Ealing Council is advising residents to keep children and animals away from hairy caterpillars and their nests in oak trees to avoid itching skin rashes and other health problems.

Oak processionary moth (OPM) caterpillars could be nesting in some oak trees across the borough. They have tiny hairs which contain a protein that can cause itchy skin rashes and, less frequently, eye and throat irritations and breathing difficulties in people and animals. 

The greatest risk period is May to July, although nests should not be approached at any time because detached hairs remain within them. 

Ealing Council works with the Forestry Commission when required to tackle the nests and moth population in its parks and open spaces with carefully controlled tree treatment and nest removal.

The Forestry Commission advises that the OPM caterpillars only build their nests on the trunks and branches of oak trees. 

They are only rarely found in other trees, and usually only if they run out of oak leaves to eat.

Anyone displaying symptoms including skin or eye irritations following possible OPM caterpillars should visit a pharmacist, or call NHS111 for more-serious reactions. Contact a vet if an animal is affected.

 
More health advice is also available from the “Insects that bite or sting” area of the NHS Choices website, www.nhs.uk/livewell

Guidance and information about OPM caterpillars is available via the Forest Research website at www.forestresearch.gov.uk/opm

Householders who find evidence of the pest in their own oak trees should report it to the Forestry Commission via email at opm@forestrycommission.gov.uk or by calling 0300 067 4442.