Dangerous for animals, humans and the trees they colonize, processionary caterpillars are difficult to manage, especially since with global warming, they are proliferating more and more.
The processionary caterpillars are back and this more and more early. And their proliferation over almost the entire territory can be worrying. A decree issued in 2022 by the government classified two species – pine and oak – as harmful to human health.
As their name suggests, as soon as the fine weather arrives, these caterpillars begin a procession along the trees where they previously nested to the ground where they burrow. It is during this journey that the risk of contact is the highest.
Particularly dangerous for animals
Processionary caterpillars are covered in hair that can be dangerous if touched. This contact can be direct cutaneous or indirect, even by inhalation, because these hairs can be detached while keeping their stinging property.
Contact is not fatal for humans but it can cause allergic reactions, especially on the skin, and can also attack the eyes if hair gets stuck there.
Children and pets, especially dogs and cats, on the other hand, may develop more severe symptoms because they are more likely to come into direct contact with the caterpillars.
“Animals can be affected at the level of the tongue and the truffle in particular, it can cause necrosis and go as far as death for certain serious cases”, explains to BFMTV Alice Samana, host of the Observatory of processionary caterpillars.
“You don’t have to kill them 100%”
However, the solutions to protect against it are rare. “We must not kill them 100% everywhere”, abounds Alice Samana. “They serve other animals, for example, they feed tits”. The specialist thus recommends rather to “manage them” and to act “according to the place”.
For example, in a school yard or park with lots of animals and people, they need to be removed. But in a forest, you can let them live.”
According to Alice Samana, if chemical treatments exist, natural tools are the most effective. The first is to install tit houses, natural predators of caterpillars.
Another solution is to set traps. “We place a completely waterproof collar around the tree so as to receive all the caterpillars that come in procession and which will fall into a plastic bag”, explains Jérémy Thomas, manager of a company specializing in pest management.
To protect yourself, specialists advise in particular to wear long clothes and closed shoes during walks in the forest or even in a park.