Overview
- Local officials reported a sharp 2026 rise in nest numbers, with Rotenburg removing more than 308 nests this year compared with roughly 50 in 2024–25 combined.
- The caterpillars carry microscopic irritating hairs that can cause itchy skin rashes, eye inflammation and, in rare cases, respiratory distress or severe allergic reactions.
- Municipalities and landowners are responsible for control and are using specialist vacuuming, hot foam, targeted biocides or released nematodes while treating contaminated gear and waste as hazardous.
- Outbreaks have been confirmed in Denmark, including heavy infestations in Odense linked by experts to imported oaks, and authorities have closed affected zoo areas and increased removals and warnings.
- Officials warn climate trends will likely sustain further increases, creating rising costs and logistical burdens that cities plan to meet with training, fewer new oak plantings and measures to boost natural predators.