The oak processionary moth (Thaumetopoea processionea) belongs to processionary moths, which comprises around one hundred different species. In popular parlance, the oak processionary moth is often confused with the oak moth. The oak moth is also a species of butterfly, but it belongs to the species clucking.
The oak processionary moth is a plant and health pest that – as the name suggests – occurs primarily on oak trees. The genera red oak, sessile oak and pedunculate oak are mostly affected.
The oak processionary moths owe their names to their typical processing behaviour from their nests into the oak crowns to feed on leaves. Oak processionary moths prefer a dry, warm climate and multiply and geographically spread in parched years. As “sun worshipers”, you will find them mainly in oak forests that are not too densely overgrown, forest edges (southern orientation) and on individual oak trees.
The oak processionary moth can be dangerous. Not so much as a plant pest, but more as a health pest: In the larval stage, the oak processionary caterpillars carry poisonous stinging hairs that can cause symptoms such as skin rash (caterpillar dermatitis), allergies or inflammation of the eyes and airways in humans.