Toxic oak processionary caterpillars are infesting trees across Germany and Switzerland, forcing the closure of parks, playgrounds, and sports fields [1, 2, 4].
These closures are necessary because the caterpillars possess stinging hairs that can trigger severe allergic reactions, skin irritation, and respiratory distress in humans [1, 3]. The scale of the infestation has disrupted public access to outdoor recreation areas in several regions.
Reports indicate widespread activity in Germany, specifically within Berlin and Brandenburg [1, 3]. Other affected locations include Neufahrn in Bavaria, Dautphetal in Hessen, and Königs-Wusterhausen in Brandenburg [2, 4]. The issue extends beyond German borders, with the municipality of Ins in the canton of Bern, Switzerland, also implementing area closures [5].
Local authorities are employing various methods to manage the pest. These countermeasures include the use of biocides, vacuuming the larvae, and thermal treatment through flaming [1, 3]. Some reports suggest the infestation has been more severe recently than in previous years [6].
The caterpillars typically target oak trees, where they create webs that protect the colony. When the larvae release their stinging hairs into the air, they can affect people who are not in direct contact with the insects, creating a hazard for anyone walking beneath infested branches [3].
Public health officials continue to monitor the spread as municipalities struggle to keep public spaces safe. The combination of biological control and physical removal remains the primary strategy to mitigate the health risks posed to the general population [1, 3].
“Toxic oak processionary caterpillars are infesting trees across Germany and Switzerland.”
The increasing prevalence of oak processionary caterpillars represents a growing intersection between urban forestry and public health. As these pests expand their range or increase in population density, cities must balance the maintenance of green spaces with the need to protect citizens from airborne toxins, potentially leading to more frequent and prolonged closures of public infrastructure.
