Category Archives: Wildlife

Why You Need to Know about Processionary Caterpillars

It’s Spring, at last (at least it was a few days ago – it’s raining again today and feeling more like Autumn again, but hey ho.) At this time of year everything comes alive and the ground starts crawling with critters. Most of these are harmless, friendly even, but then there are a few others we have to watch out for. One of the most prolific of these is the pine processionary caterpillar which, after having spent months in their fluffy-looking nests high up in the pine trees, make their way down to earth for the final stage of their life cycle (as caterpillars) where they then burrow into the ground in order to pupate, hatching a short time later as the Pine Processionary Moth (Thaumetopoea Pityocampa).

A silk cocoon hanging on the tips of a pine tree
Silk Cocoon of the Pine Processionary Caterpillar
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The Distinctive Pine Processionary Caterpillar
I first saw these on a walk with DS and DD last year. At the time we didn’t know what they were but luckily I knew better than to touch an unidentified furry crawly and rightly too, as it turns out. Because as harmless as they appear – how much damage can a small fluffy looking caterpillar do? – they are in fact quite toxic. Not so bad to healthy humans;  we can expect a rash, which can be pretty nasty – the picture on Google images don’t look all that appealing but, risk of anaphylactic shock aside, it’s usually a localised reaction somewhere on the body and eventually clears up.  As with all things of this nature it’s best to keep your kids from picking them up or rolling around on the ground anywhere where they’re likely to be found. For dogs (and sometimes cats – although cats apparently keep their distance more often than not) they can be fatal, as a friend living in Spain, so a few weeks ahead in the life-cycle, discovered just a few weeks earlier. Her dogs made it, luckily, but it was a close shave and one she could have avoided if she’d known more about the dangers beforehand.

Personally, while I’m usually quite nervous of pests (and general pestilence) in this instance I’m mostly just relieved they’re not spiders – which is what I thought they were when I first saw the giant cocoons on the tips of the tree branches. But then I don’t have dogs. For any doggy owners, there’s some really useful information on this website and a very thorough write up of a doggy encounter with them on this other blog, ouiinfrance.com. In short, to protect your animals you need to prevent them from having any contact, not only with the caterpillars themselves but also with the spines, which are the cause of the problems. If they have an encounter with any caterpillars the advice is to get them to the emergency vet, so if this is you – go now. Go!!

The question I have though is how to get rid of them and what is being done about it because they really are prolific and I can see that if no action is taken this problem is only going to get worse. In future we may end up in closer proximity to them – while they’re around now there aren’t any particularly close by so unless my cats wander off into the woods, which are about 1/4 of a mile up the road, they’re unlikely to come into direct contact with them.

While these are common across much of Western Europe, different countries have different policies, as you’d expect. In France there’s a directive which places the onus on the land owner but requires action at the local level to be enforced. All good with the obvious problem that unless it’s enforced – and I’d say from the number of nests around here that it isn’t –  it’s unlikely to make the least bit of difference. Plus there’s so much land and so many owners, many of whom are scattered over the entirety of the globe, which means and not all land has an obvious owner, or at least not an owner on hand to actively manage it. Since the pesticides that were used to eradicate them are now banned (good) the best methods involve removing the nests and burning them (not good since fires can easily get out of hand and the act of removing the branches/nest can spread the dangerous hairs) or traps, which are the most ecological solution. The basic principle of the trap exploits a weakness in the caterpillars programming. You see these creatures, once they leave the nest, head to tail, seem to have no compulsion to go around anything, so as soon as they hit the barrier they just go round and round. Or rather, the first one goes round and round and the rest just follow! This discovery was thanks to a French naturalist, Jean Henri Fabre, who wrote a book entitled The Life of the Caterpillar (which is available to read online) about them. One day while studying them he managed to coerce them into forming a loop, so they were all equally following and leading, walking in circle. To his surprise them they continued this way for the best part of four days. Fast forward to today and four days is ample time for a trap to be set up and emptied. Game on.

The traps are designed so that a small tube leads out of the barrier into a collection bag, which you can then dispose of safely. There’s an official product, called Eco Piège, which you can pay upwards of 35 euros for (yeah, right), or you can go DIY.  Some cheap and cheerful DIY barrier ideas include using pipe lagging, some pipe and a bin bag, as in the picture below, posted by Linda Garnett to Facebook.

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DIY Processionary Caterpillar Trap using Pipe Lagging
Another simple idea used recycled water bottles – but of course now I can’t find the photograph to share. Also I’ve seen pictures of clear plastic gaffer-taped to the trunk of the tree, kind of like a large buster collar (the kind you put on your dog or cat to stop them scratching their stitches out). However you do it, the best approach seems to be one that involves funneling them into a container that you can easily seal in order to limit your contact with them.

As an alternative to catching the live caterpillars and then having to dispose of them, Farber recommends checking the tips of the trees for eggs and removing the branch tips before they hatch, so no cocoons or dangerous fibres to have to deal with. That might be a worthwhile approach if you’ve only got a few trees in a fairly small area and can easily keep a close eye on them but on the scale of the problem as it seems to be around here, that would be a lot of work!

So there you have it. You have been warned! Personally I hope I never have to put up with these on my doorstep but, if I do, at least I’ll have some ideas about how to get rid of them. And in the meantime I’ll be keeping myself, my pets and my kids well out of their way!

28/04/18 Update – I managed to get an up-close cocoon shot so have added it above. 

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A Month of Many Moths

Three weeks or so ago an unusual looking moth arrived in our village. The moths arrived en masse and everyone noticed them. We talked with M, our neighbour, who wasn’t sure what they were and seemed to be suggesting, at least from the way she kept gesturing towards our Morning Glory flowers and the straw bale vegetable patch, that their appearance for the first time was somehow connected with our presence and our strange new ways.

A picture of the Box Tree Moth on a piece of wooden board
One of the thousands (millions?) of Box Tree Moths that have taken over the village

I searched online and didn’t find anything. The next day M told us that she’d heard about them on the news as their arrival was something of a local phenomenon. The species was the Pyral de Buis (Box Tree Moth or Cydalima perspectalis), an invasive species that arrived in Europe via Germany in 2006, reaching France in 2009. Originally from China, it’s preferred food is box wood, on which it lays its eggs before the caterpillars hatch and duly decimate it.

For the first few days we enjoyed the spectacle, especially when, on about day three, an enormous flock of swallows also arrived, eating them on the wing. We would stand on the balcony and give the fence a shake, which would cause a huge cloud of them to take to the air, at which point the swallows would move in, chasing and swooping, picking the out of the air. Here’s a short video I shot on my phone.

​But the novelty has worn off. They are everywhere: in the house, on virtually every leaf, and busy on the figs. They seem to be here for the fruit, with the moths gathering to feed on the figs to the extent that they are crowding out the wasps who usually feast on them! Having read up a bit about them online there’s not much that can be done. There’s a pheromone trap that attracts the males but they’re expensive to buy. Our other neighbour, P, is so sick of them he’s been setting a light trap at night, content simply to reduce their numbers by a few hundred at a time. Not that it makes any difference because they’re everywhere, dead and alive; in the car, the house, in the plants, the washing – basically anything outside. The moths have basically taken over the place! Even the birds can’t keep up, visiting every three days or so, taking their fill then disappearing for a while, possibly to sleep off their feast!

While having a little potter round the village with DS I noticed they were also eating the grapes and asked another neighbour about their impact on the wine harvest, but he said something about pesticides and suggested they weren’t a problem! There isn’t any box wood in the immediate vicinity of here but there is a lot of it around so I would imagine it was being decimated as the only way to rid the plant of the caterpillars is to drench the plant repeatedly with pesticide and no-ones going to be doing that on the necessary scale anytime soon. Nice.

So there’s that.

Another new (to me) moth is this one, which I found sitting on the road.

A picture of a tiger moth, with white and brown wings, on grey concrete.
A Garden (or Great) Tiger Moth, resting on the road

When I moved it to a safer place it opened its wings slightly to reveal the stunning red hindwings. I’ve not seen one before or since so I am glad I got to photograph and identify it. It’s a tiger moth (Arctia caja)! I do think the name is a bit weird because it’s markings are more giraffe-like than tiger-like but hey. I can’t believe I’ve never seen one before, even though they’re listed as common in the UK. Beautiful!

A Tiger Moth displaying resting on a cucumber plant leaf displaying its red and black underwing.
A tiger moth showing it’s red and black spotted hindwings.

There are other creatures I’ve not seen before around but my phone keeps running out of memory so I’ve not managed to get photos, which make identification after the fact a bit difficult. The only other one I can definitely remember is the Slender Scotch Burnet (Zygaena loti), which some of the kids at the school were “playing” with when we were there the other evening. Unfortunately, one of its hindwings was broken and kids being kids they weren’t all that gentle with it. What was nice was that they were really examining it closely, as well as having made a “home” for it out of sticks, twigs, leaves and petals. In the UK this is a priority species listed in the Red Book. I hope they don’t have the same status here in France because the kids really weren’t interested in its conservation value!