An oak processionary caterpillar was found on campus today. Where? In front of the Refter, on a bench. The little creature can cause asthmatic symptoms, red hives and swollen eyes.

Certainly, confirms the Butterfly foundation, we are dealing with an oak processionary caterpillar. The writer of this piece was eating a salad on a bench in front of the Refter and found a grey caterpillar next to her plate. She took a photo and sent it to insect specialists in Wageningen. The confirmation came quickly.

What now? Rob Leuven is professor in invasion biology at Radboud University, and he is not surprised about the find. ‘May and Juni are peak season’, he says. ‘The creature feeds itself on oak trees, and we have enough of those on campus.’

Do students risk health problems? Leuven answers like this: ‘Basically, there is a big chance that they do not affect you. Unless you are sensitive to the caterpillar or you touch it. If you are sensitive to it, do not sit under the tree.’

Reputation

The hairy caterpillar does not have a very good reputation, because within eight hours after you touch it, it can cause asthmatic symptoms, red hives, itchiness and swollen eyes. The professor advises to notify the municipality about finding the caterpillar, which is named like this because of his ‘processionary behaviour’: walking behind other caterpillars, and form a procession.

Other processionary caterpillars have been found in Nijmegen. Exterminators are sent out to get rid of colonies.

Postscript: the author of this piece has notified the university.