Overview
- Authorities in Brandenburg and Berlin report an early‑season build‑up with a likely rise in moth numbers and the risk of large‑scale oak defoliation.
- Larvae start feeding in mid‑April, and the main health risk peaks from mid‑May to June when third‑stage caterpillars shed tiny toxic hairs that irritate skin and lungs.
- Cities plan preventive sprays of Bacillus thuringiensis in high‑use areas such as playgrounds and schools, with Brandenburg preparing the Foray ES bio‑product for feeding larvae.
- Darmstadt scheduled ground treatments and limited helicopter spraying from mid‑April, while Kassel will trial SF‑nematodes and Rhineland‑Palatinate’s road agency will apply nematodes on risky roadside trees.
- Crews will vacuum nests once they appear, Worms is adding trunk collars that trap marching caterpillars, Marburg is installing nest boxes to boost predators, and Hesse foresters may close infested woods to protect visitors.