Marauding caterpillars with toxic hairs have brought parts of Germany to a standstill, leading to closures of swimming pools, restaurants, public parks and sections of the motorway.
Oak processionary moth caterpillars, named after the nose-to-tail processions they form to travel between the oak trees they devour, have fine, long hairs with an irritating toxin that can cause blistering rashes, feverish dizzy spells and asthma attacks.
For years, the caterpillar used to be a relatively rare sight in Germany, found only in isolated areas of woodland. But following a this year’s mild spring and warm, dry summer, the oak processionary’s nests have been found in large numbers all over the country.
Cities and towns in Brandenburg, Saxony-Anhalt, Baden-Württemberg, Bavaria and the western state of North Rhine-Westphalia have been particularly badly affected.
In the city of Münster, six people had to have eye operations to remove caterpillar hair that got stuck in their corneas. In Mülheim, nine children were taken to a hospital last month after suffering rashes and breathing problems during a sports day.
“It’s terrible everywhere,” Thomas Schwolow, an administrator in the municipality of Issum, where numerous trees have been affected, told Rheinische Post. “It would be great if it would rain so that at least all the hair on the leaves and in the air could be washed away,” he added.
Dortmund’s Fredenbaumpark, where nearly 500 trees were found to be infested, was closed for three weeks, broadcaster Deutschlandfunk reported.
“The oak processionary infestation this year is very intensive – much more than last year,” said the park’s manager, Frank Dartsch.
In Nuremberg, organisers of a rock festival had to hire a private company to remove processionary nests that had infested about 50 trees where the concert was due to be held.
In Frankfurt, authorities have used helicopters in the battle against the caterpillar, spraying 220 hectares of forest with biocides that stop the larvae from eating oak leaves and makes them die off.
Near Hamburg in northern Germany, parts of the A1 motorway were closed for three nights in May so firefighters could tackle infected trees. Authorities were concerned that the caterpillar’s hairs, which are almost invisible, could affect the health of drivers and local residents.
In Louvain, Belgium, firefighters had to destroy nests of the invasive species before a rock concert.
Oak processionary moth caterpillars begin to pupate in early July, but the threat posed by their nests remains. Each caterpillar can have up to 700,000 hook-ended hairs, and the toxins they contain can remain active several years after the caterpillar has pupated into an adult moth.