Denmark preparing for toxic caterpillar invasion – The Post

Denmark preparing for toxic caterpillar invasion

Roads, restaurants and parks closed in Germany as caterpillars hospitalise over ten people

And they are all playing follow-my-leader all the way to Denmark (photo: Luc Hoogenstein)
July 8th, 2019 10:33 am| by Ben Hamilton

As predicted in late May, conditions this summer have so far been favourable for the oak processionary moth (Thaumetopoea processionea), and several German cities are currently battling its toxic larva – a  caterpillar that carries poisonous hairs that can cause skin irritation and asthma among humans.

A number of roads, restaurants and parks have been closed and several people have been hospitalised over the last month: nine in Mülheim, which is in western Germany, and six in Münster, which is again in western Germany.

Sightings in Denmark
Sightings of the moth have even been recorded on the south side of Lolland-Falster, although the general consensus is that the caterpillar won’t pose a major threat this year.

Nevertheless, the Danish authorities are preparing for the worst and enacting a plan to eradicate as many of the insects as possible.

July and August tend to be their most active months, and while the moth is not an invasive species in Germany, last year’s drought has resulted in many more breeding this year.

Mostly males sighted … so far
“Male [oak processionary moths] have already been caught on the south side of Lolland-Falster,” Iben Margrete Thomsen, a senior advisor at the Department of Geosciences and Nature Management at the University of Copenhagen, which is advising municipalities on action plans, confirmed to DR.

“Males fly much longer than females do. But the expectation is that they will come to Denmark at some point. But if it is in five or ten years, or just a year, we do not know.”

Hoovering up the bugs
Special devices are available to suction up the bugs, according to Thomsen, and the municipalities are being advised on the correct protective gear and how to locate and eradicate nests.

The nests can be particularly problematic, as when the moth emerges from the larva, it remains poisonous. Each one has 60,000 minute hairs, which if inhaled can cause all manner of problems. Another issue are the eggs, which are particularly small and difficult to see.

Toxic caterpillars


– The caterpillars are typically found in oak forests

– They travel in nose-to-tail processions (hence their name), often arrow-headed, with a leader followed by rows of several caterpillars abreast

– The caterpillars have around 62,000 hairs full of a poisonous protein called thaumetopoein they secrete when they feel threatened, so people can be affected by touching the caterpillars but also by inhaling wind-borne hairs.

– Inhaling the caterpillar’s hairs can cause rash, respiratory problems, nausea and vomiting,

– Avoiding contact with the larva is advised – whether it is alive and dead. Don’t pick it up. Avoid breathing close to it

– If you come into contact with a caterpillar, or breathe close to it, take off your clothes and wash with water and soap

– If you experience problems with breathing, seek medical attention

– There is a relative of the moth already living in Bornholm – the pine processionary moth. It has caused a number of people to be hospitalised recently.