Save the trees - report sightings of the tree pest Oak Processionary Moth
29th May 2020
We need your help in reporting any sightings of the tree pest Oak Processionary Moth (OPM) caterpillars.
The OPM was first identified in London in 2006. The caterpillars and their nests contain hairs which can cause itchy rashes, eye and throat irritations, and should not be touched under any circumstances at any time. The greatest risk period is May to July when the caterpillars emerge and feed before pupating into adult moths.
You can identify them by their nests that are typically dome or teardrop-shaped, averaging the size of a tennis ball. They are white when fresh, but soon become discoloured and brown.
They feed on oak leaves and can increase trees’ vulnerability to attack by other pests and diseases, making them less able to withstand adverse weather conditions such as drought and floods. A government programme is in place to limit their spread from areas where they are present.
The Forestry Commission, working in partnership with others, has an annual programme in place to tackle the pest, with an ongoing programme of surveillance, treatment and research.
Andrew Hall, Forestry Commission Operations Manager, said: “At this time of year, many people are enjoying green spaces and it’s really important for the public to be aware of the risk of tree pests like Oak Processionary Moth and to report any sightings via our TreeAlert website or by calling the Forestry Commission. This will help us with our programme of treatment and enables us to slow the spread of this pest.”
Cllr Chris Lloyd, Lead Member for Leisure, added: “Our award-winning open spaces and parks are very popular with local communities and visitors. People use them for exercising, relaxing and picnics too. Controlling these pests will help preserve our woodlands and communities can keep enjoying using these open spaces.
“Please help reduce the impact of OPM caterpillars on human health by reporting any sightings immediately. Do keep alert, stay safe, keep healthy, and observe the social distancing rules currently in place by keeping 2 meters apart.”
Please report any sightings to the Forestry Commission via its Tree Alert online portal, email firstname.lastname@example.org or you can call them on 0300 067 4442 with a precise description of the tree’s location.
For more information on how to identify OPM, including common mistaken species, visit