It is quiet around the oak processionary caterpillar. Where in recent years in the spring it was often about the caterpillar with its stinging hairs, it is now quiet. Will the animal infest us again this year? Or will there not be that many? Even oak processionary caterpillar expert Silvia Hellingman is in for a surprise.
“Due to the cold weather in the spring, the oak processionary caterpillars have been delayed somewhat this year,” says Hellingman. “In addition, it is also questionable how many caterpillars there are this year, because there were relatively few butterflies last year.”
That sounds optimistic. But that is not necessarily the expert. “Because the question is how many are underground. The warm summer of last year caused many caterpillars to settle underground. We dug around trees and discovered that they sometimes made nests 25 centimeters deep. It is possible that these caterpillars come out this spring.”
According to Hellingman, we can keep an eye out for that from June. If there are many caterpillars low on the trunk, these are probably the animals that did not emerge last year. “That is why we can soon have an explosion of oak processionary caterpillars. If you see that on a tree, you must report it to the municipality,” she advises.
However, municipalities cannot do much during that period. Especially in recent weeks, they sprayed trees with, among other things, a preparation of biological bacteria, as the municipality of Coevorden did. “The caterpillars get their stinging hairs at the beginning of June,” says Hellingman. “If you then fight the caterpillars, you spread the fire hairs.”