Oak Processionary Caterpillar

For the past twenty years or so, the oak processionary caterpillar has been found in large numbers in the Netherlands during the summer. There is hardly an oak tree that is left undisturbed by this hairy caterpillar from May through August. The caterpillar’s hairs cause discomfort and irritation to the skin, eyes, and respiratory tract. The municipality is taking measures to control the oak processionary caterpillar in public spaces.

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

2. Control
The marked trees will be visited within a week by a specialized company that will vacuum up the oak processionary caterpillar nests. Vacuuming is a natural and environmentally friendly approach that does not harm other insects. Burning or the use of poison are also possibilities, but these are options we do not use. 

What can you do on your own?

Do you own an oak tree infested with oak processionary caterpillars? If so, you are responsible for removing the caterpillars. It is not mandatory, but we do recommend it. Removing the caterpillars is a difficult task. It’s best to hire a specialist for this. 

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 by calling14 071or usingthe reporting system at.