If you are organising an event during a period when there is a risk of disruption caused by the oak processionary caterpillar, you can take your own precautions. For example, bear the oak processionary caterpillar in mind when setting up the venue.
Oak processionary caterpillars during your event
If there are nests of oak processionary caterpillars in trees, you are responsible for removing them yourself. You should engage a specialist company to do this. You can find out how to report nests in council-owned trees on the Page on Nuisance and Hazards Caused by Animals.