Overview

• 73% of affected municipalities in North Rhine-Westphalia reported a decline in oak processionary moth nests in 2024, with further reductions expected this summer.
• Experts attribute the population decrease primarily to ecological self-regulation, including natural predators like parasitoid flies and wasps, and rainy summers disrupting larval development.
• Despite the decline, municipalities are using targeted interventions such as vacuum removal, biocides, and experimental pheromone traps to combat remaining infestations.
• The larvae's toxic hairs, which can cause severe allergic reactions and respiratory issues, remain a significant public health concern, prompting continued safety protocols for exposed individuals.
• Climate change, with warmer and drier conditions, is identified as a key factor enabling the species' past proliferation, complicating long-term control efforts.