We use some essential cookies to make this website work.
We’d like to set additional cookies to understand how you use forestresearch.gov.uk, remember your settings and improve our services.
Preparing to search
The following pictures show oak processionary moths, caterpillars and nests in a variety of situations.
A procession of OPM caterpillars on the trunk of an oak tree. (Picture: Henry Kuppen)
Single- and multi-file processions, clusters and single OPM caterpillars on the trunk of an oak tree. (Picture: Henry Kuppen)
A procession of OPM catepillars across the ground. Such processions are most likely to be seen close to oak trees. (Picture: Mark Townsend, Gristwood & Thoms)
OPM caterpillars in a feeding cluster, showing partially consumed oak leaves.
A large OPM nest on the trunk of an oak tree, with caterpillars visible inside. The nest is still white, indicating that is fairly new – see next picture.
Discoloured OPM nest – they are almost white when new. (Picture: Ralph Parks, Forestry Commission)
A disintegrating OPM nest on the trunk of an oak tree
A group of OPM nests around the base of an oak tree. Silken threads extending up the trunk from the nests can be seen on the right.
A small OPM nest on the underside of a high branch of an oak tree. Binoculars, and surveying in winter when the trees have no leaves, can help to find such nests.
An OPM moth, the adult form of the insect. OPM moths are difficult to distinguish from other species, so we do not ask for reports of them. However, we will take reports of females caught in light traps by moth recorders who know how to accurately identify them.
Unless otherwise stated, pictures were taken by Forest Research and are Crown copyright.
Cookies are files saved on your phone, tablet or computer when you visit a website.
Find out more about cookies on forestresearch.gov.uk
We use 3 types of cookie. You can choose which cookies you're happy for us to use.
These essential cookies do things like remember your progress through a form. They always need to be on.
We use Google Analytics to measure how you use the website so we can improve it based on user needs. Google Analytics sets cookies that store anonymised information about: how you got to the site the pages you visit on forestresearch.gov.uk and how long you spend on each page what you click on while you're visiting the site
Some forestresearch.gov.uk pages may contain content from other sites, like YouTube or Flickr, which may set their own cookies. These sites are sometimes called ‘third party’ services. This tells us how many people are seeing the content and whether it’s useful.