Processionary caterpillars now officially a harmful species in France


Processionary caterpillars, whose tiny hairs can cause irritation and respiratory problems, have been officially recognized as a harmful species in France in a new decree.

The decree of April 27 confirms that processionary caterpillars have been added to the “list of species whose propagation harms human health”.

The decree includes two types of caterpillars: the oak processionary caterpillar and the pine processionary caterpillar.

The small caterpillars are generally recognizable by their tendency to move in “lines” (or processions) on the ground and on the trunks of trees. They have tiny hairs all over their bodies, which can be harmful to humans and pets if touched or ingested.

Their nests, which are in the trees, look like cotton.

Annual increase in caterpillar poisoning

The new decree was issued due to a significant increase in “annual declarations of caterpillar poisoning” in poison control centers between 2012 and 2019, the public office website said. The number of reports rose from 44 to 178 per year, he said.

Marilou Mottet, coordinator at the national caterpillar observatory, explained to Le Parisien that the official recognition of the misdeeds of caterpillars means that “the prefects will be able, in each department concerned, to warn the population, and explain the measures to be taken”. if they see nests above playgrounds or schoolyards”.

Pine caterpillars tend to affect people the most from December to April, while oak caterpillars affect people most from May to July, the Ile-de-France Regional Health Agency (ARS) said. .

Their tiny hairs can easily come loose when touched, or can simply be blown through the air and spread by the wind.

Symptoms of irritation include:

– Painful rash with severe itching within eight hours of skin contact;
– Conjunctivitis (red, painful, watery eyes) within one to four hours of eye contact;
– Sneezing, sore throat, difficulty swallowing and possibly difficulty breathing if inhaled;
– Hypersalivation, vomiting and abdominal pain if swallowed.

The ARS advises against “approaching or touching these caterpillars or their nests”.

He also advises:

– Wear long clothes when walking in the forest
– Avoid rubbing your eyes during or after a walk
– Wash fruits and vegetables from your garden
– Avoid drying your clothes next to infested trees
– Take a shower and change your clothes if you think you have been exposed to caterpillars.
– Touched or eaten, caterpillars can also be dangerous (even fatal) to pets such as dogs and cats.

Limit the risks associated with processionary caterpillars

Caterpillars can be deterred or killed by fire or insecticide, and they are eaten by birds. Traps that attract processionary bloodlines are also available.

Due to the risk, some authorities in severely affected areas are beginning to act, especially as experts predict an increase in the caterpillar population in 2022 and 2023.

The Department of Forest Health in Aveyron, Occitanie, said: “At this stage, specialists are predicting a peak next year. »

The department uses a type of natural bacterial insecticide to control caterpillars called BTK (Bacillus thuringiensis), which is toxic to insects and caterpillars but not to humans. For maximum effect, you need to use it in the fall.

The authorities have also installed predator boxes and ecological traps specially designed for the caterpillars.

One city even went further

In 2018, the town hall of Millau (Aveyron, Occitanie) issued a decree stipulating that people who did not take measures to help eradicate the caterpillars would be liable to a fine. Residents who did not participate in local anti-caterpillar measures first received a letter recommending ways to destroy nests or trap caterpillars. Further inaction would then result in a fine of €38.

Residents have also come together to make group purchases of traps in particularly affected areas.

The caterpillars were once only visible in the south of the country near the Mediterranean basin, but are now spreading throughout France, particularly in Normandy, Brittany and the Grand Est.


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