A thin grey line - the procession caterpillar

Chenille ProcessionnaireWe used to be able to say that this region has few really nasty creepy crawlies. Climate change has made this no longer true and we've written about this more than once. One native undesirable presence – and you'll start seeing them about now – is the procession caterpillar (chenille processionnaire) which is now, entomologists say, being found at higher altitudes as they become warmer. So what exactly are we talking about? These insects – destined to turn into moths – are some 4 centimeters in length, greyish in colour with darker bands. They nest in and ravage pine trees and then move on in search of more food. They travel in a line, one behind the other, hence their name. If you come across one of their grey columns – most likely between May and September – move away fast.

The creatures are covered in hairs numbering up to 60,000 which exude a venom that causes painful lesions on the skin. These can be especially dangerous for children and animals, particularly dogs whose tongues can be literally destroyed (necrosis). If swallowed or other wise brought into contact with the skin – these hairs, which often float in the air near nests – can cause respiratory difficulties and irritation of the eyes, nose and throat. It's good to know that many local councils are taking action against these pests with targeted insecticides and traps or, in some cases, installing colonies of great tits, a bird that gulp down a huge meal of these caterpillars with no ill effects. The bad news is that, with rising average temperatures, they are rapidly moving north. Paris should be prepared by 2020.