Annual Control of the Oak Processionary Caterpillar

On Thursday, June 23, the municipality of Voorschoten will begin its annual effort to control the oak processionary caterpillar in public spaces. In recent years, the oak processionary caterpillar has been a recurring problem in Voorschoten. From May through August, there is hardly a single oak tree that is left undisturbed by this hairy caterpillar. The caterpillar’s hairs cause discomfort and irritation to the skin, eyes, and respiratory tract.

How do we control the caterpillar?

Starting in 2022, the municipality of Voorschoten will focus on proactively combating the oak processionary caterpillar. The following steps will be taken:

1. Risk Assessment and Documentation

All oak trees owned by the Municipality of Voorschoten are inspected in advance for oak processionary caterpillar nests. These trees are registered, and if nests are found, the trees are marked.

2. Control 

Within a week, the marked trees will be visited by a specialized company that will vacuum up the oak processionary caterpillar nests.

We opt for the most natural approach possible to controlling the oak processionary caterpillar. We actively control the infestation by vacuuming up the nests. Burning or using poison is also an option, but those are methods we do not use. This way, we control the infestation in an environmentally friendly manner so that other insects are not harmed.

Report an oak processionary caterpillar

The oak processionary caterpillar lives only in oak trees. Its nest can be recognized by the white web. If you see an oak processionary caterpillar nest in an oak tree, please report it to the municipality as soon as possible by calling 14071or usingthe reporting system at.