Toxic processionary caterpillars invade Eure-et-Loir

After hatching from cotton-wool-like cocoons in trees, the caterpillars - known in French as “chenilles processionnaires” (so-called because of their tendency to move in processionary lines) - then congregate on walls or on the ground, and grow to a couple of centimetres in length, reports French news source FranceInfo.

Despite their soft-sounding name, chenille caterpillars are actually dangerous, and carry thousands of small fibres that are irritants to humans and animals, giving off a toxin that can cause serious damage to throats, skin and eyes.

Now, they have especially affected the department’s Lucé neighbourhood, and reports suggest that several pet cats in the area have already been affected, with some allegedly having died after eating the caterpillars. Dogs and other pets would also be at risk.

“Since they have been here, I have not been opening my windows because I do not want the caterpillars to come inside. I cannot hang my washing up outside anymore either, because as soon as you bring it back inside, there are caterpillars on it,” said one resident to FranceInfo.

Residents have now called on their local housing authority, who came to confirm the invasion and begin measures to remove it.

Previously seen mainly in the south of France, processionary caterpillar numbers are only expected to grow in future across the entire country, due to global warming and rising temperatures.

However, it is now illegal to spray them with pesticides or chemicals, as these same products can also harm bees.

Instead, communities and residents are being encouraged to thwart the threat with natural predators, and provide nesting boxes for birds - including the great tit, coaltit and great spotted cuckoo - who will happily eat hundreds of the caterpillars in one day.

These birds are more likely to be attracted to nesting boxes containing black sunflower seeds, suet, and peanuts.

Another way to get rid of the caterpillars is to call on your local Mairie (town hall), which can find a pest-control firm to destroy their original nests.

It is not recommended to try to deal with the nests yourself, as anyone touching them without proper protection is likely to be affected by the toxins.