Nature
There is something good about the cold and wet spring: fewer oak processionary caterpillars will be observed this year. Although this does pose a problem for research into the annoying caterpillar.
Until a few years ago, the oak processionary caterpillar was a growing problem in our region. It is a native species, but where the caterpillar comes into contact with humans, it is controlled, because the animal’s stinging hairs can lead to health problems. The caterpillar was noticed in more and more places and so the nuisance also increased.
Since 2021, researchers in the province of Antwerp, where the oak processionary caterpillar is most common, have counted fewer specimens every year. “Last year we found very few nests,” says provincial expert Kathleen Verstraete. “Caterpillars were only present locally and these were usually small nests, no larger than a tennis ball.”
The explanation may lie in the cold and wet weather in spring: oaks then bloom later, which leads to less available food for the oak processionary caterpillar. A wet autumn also makes it more difficult for the butterflies of the species to lay their eggs.
There are now so few caterpillars that the researchers are calling on municipalities not to combat young caterpillars, but to notify the province so that it can collect the animals for research. The expectation is that the species will one day recover and therefore continued research is needed.