Identifying OPM For further information

1 They live almost exclusively in trees, which Visit: forestry.gov.uk/opm are identifiable by their distinctive leaves. Tel: 0845 367 3787 2 They move in nose-to-tail processions, in oak trees or on the ground, hence their name. E-mail: enquiries@ 3 They often cluster together. forestry.gsi.gov.uk 4 They build white, silken webbing trails and nests – usually dome or teardrop-shaped – on oak trunks and branches Oak Processionary (not among the leaves). Health information 5 The nests soon become discoloured. is available from NHS Caterpillars 1 3 Choices at www.nhs.uk/ Livewell/bites-and-stings Information for the public

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The Forestry Commission will consider all requests to make the content of publications available in alternative L Moraal, Wageningen URC formats. Please send any such requests 5 to [email protected] or call 0300 067 5046.

forestry.gov.uk/england Gristwood & Toms Ralph Parks

Forestry Commission If you see nests or caterpillars: woodlands have been certified in accordance with the • Follow the advice in this leaflet for staying safe. rules of the Forest • Report it to us using our Tree Alert app or on-line reporting FSC® C011771 Stewardship Council. form available at forestry.gov.uk/opm; or • Report it to your Council. Published by Forestry Commission England, 620 Bristol Business Park, Coldharbour Lane, Bristol BS16 1EJ 0845 367 3787; [email protected] forestry.gov.uk/england But first, please: © Crown copyright Printed on FSC • CHECK that they’re in or near an oak tree - OPM certified paper. Please recycle caterpillars usually only attack other trees if they run out of FCE/PH/OPML1/May2014/80,000/Camargue/Philtone Litho Ltd after use. oak leaves to eat. forestry.gov.uk/opm Key facts Controlling OPM Protecting Yourself

Caterpillars of the Oak Left uncontrolled, it would Caterpillars start emerging Infested trees are found by Processionary Moth (OPM) spread across much in April from eggs laid in professional and volunteer Know how to recognise oak trees, are a pest which can be of Britain. oak trees the previous surveyors, tree- and ground- caterpillars, and their nests and trails a hazard to the health summer. The most effective care professionals, and Our precious oak trees (see pictures overleaf); of oak trees, people and control method is to treat members of the public could be at risk, people in this area. affected oak trees with reporting sightings. We use keep away from caterpillars and nests. could be deterred from insecticide during the spring pheromone trapping in Their tiny hairs can be visiting or working in teach your children to keep away. and summer while the late summer to find adult blown about by the wind woodlands, animals could caterpillars are about. , which provides and cause itchy skin be exposed to suffering, keep your pets away. Caterpillars and clues to where we should rashes, eye and throat and control could become With careful timing and nests can be on the ground, and animals look the following year. irritations and, occasionally, prohibitively expensive. application, the most-used can suffer considerable distress from breathing difficulties in insecticide will affect only hairs in their mouths and noses. The Forestry Commission, people and animals. a small range of local authorities and do not try removing nests or caterpillars species. It is not known to The caterpillars eat oak landowners are working yourself – report them to the Forestry harm people, pets, livestock leaves. Large numbers hard to control this pest Commission or your Council. and most other animals. can strip whole trees bare, so that we can continue Spraying is mostly done See a pharmacist if you need relief from leaving them vulnerable to safely enjoy our parks, from the ground, and is a skin or eye irritation following to other threats. gardens and woodlands. supplemented by removing possible OPM contact. You can help by reporting OPM is a native species caterpillars’ nests. This signs of OPM to us of southern Europe is most effectively done See a GP or consult NHS111 if you or your Council. which was accidentally with vacuum equipment have a serious allergic reaction. OPM gets its name from the introduced to England. when the caterpillars are caterpillars’ habit of moving Contact a vet if your pet pupating into adult moths. in nose-to-tail processions, has been affected. sometimes on the ground beneath oak trees, as in this picture. Further health advice is available in the “ that bite or sting” area of www.nhs.uk/livewell website Human and health Tree health

The caterpillars have OPM caterpillars can be a thousands of tiny hairs which hazard to oak trees because The greatest risk period contain an irritating substance they feed on the leaves. is May to July, but nests called thaumetopoein. Large populations can strip Contact with the hairs can trees bare, leaving them should always be avoided cause itching skin rashes vulnerable to other pests because they can contain and, less commonly, sore and diseases, and less able thousands of shed hairs. throats, breathing difficulties to withstand events such as and eye irritations. drought and flood. Henry Kuppen