The Oak Processionary Moth (OPM) is a tree pest that has been spreading rapidly in the South East. Its caterpillars only feed on the leaves of several species of oak trees. They cannot complete their development on any other trees.
Over the last few years, we have had numerous OPM sightings on private properties and EBC owned land. We are monitoring the situation very closely, working in partnership with our Tree Services, the Forestry Commission, Surrey County Council and advising private landowners on what steps to take.
What do OPM look like?
They have long, white hairs, a grey body and dark head. Older larvae have a central dark stripe with paler lines down each side. They build white silk-type nests in the branches or trunks of trees (not in the leaves). See images attached.
Where can they be found?
They can be spotted on oak tree trunks moving about in late spring and early summer (May, June and July) in nose to tail processions – hence their name. Lines of caterpillars are often arrow headed. They can sometimes be found on the ground moving between trees in this procession.
What is the risk to residents?
The caterpillars and their nests contain hairs which can cause itchy rashes, eye and throat irritations and in some very rare cases, allergic reaction in people and animals who you come in contact with them. The greatest risk period is May to July when the caterpillars emerge and feed before pupating into adult moths. Please be mindful that caterpillars can shed hairs if they are disturbed or threatened. The hairs can be blown by the wind, stick to trunks, branches, grass and clothing. In warm weather, hairs can stick to the skin more easily when you wear sun protection lotion, so please be mindful not to approach oak trees then.
What to do when you spot an OPM nest: -
When you see posters at affected sites, it is important not to ignore them. Please stay well clear of the affected trees for your own safety. Make you keep dogs under control, away from infested areas.
- If the sighting is on private land, please report it to the Forestry Commission using the Tree Alert online reporting form on their website: https://treealert.forestresearch.gov.uk/
- If you cannot use Tree alert, you can report them by telephone on 0300 067 442 or by email at email@example.com. If you own the tree on which the nest if located, the Forestry Commission has issued an online manual for owners of oak trees.
- If the OPM are found on am Elmbridge Borough Council-owned tree, report it to us on 01372 474825, 01372 474579 or by email firstname.lastname@example.org.
Cllr Janet Turner, Portfolio Holder for Leisure and Culture, said,
“At this time of year, many people are enjoying green spaces and it’s really important for residents and visitors to be aware of the risk of Oak Processionary Moth (OPM).
We are aware of the presence of OPM in the borough and are monitoring the situation closely. We are removing nests or spraying infected areas if they cause a serious threat to the community. We will continue to do so where OPM cause the most risk to residents.
The Countryside Team is busy answering many calls regarding OPM. Before reporting the issue, please make sure you know whom to contact: sightings on council-owned land can be reported to the countryside team, but if they are located on private land, reporting them via the Tree Alert website or calling the Forestry Commission will speed up the treatment process and help slow the OPM spread.”
For further information, please visit elmbridge.gov.uk/leisure, email email@example.com or call 01372 474579.