Processionary Caterpillars

Just an update. We had some beautiful weather last week following a very wet spell meaning that the garden was soft and soggy. While keeping my fingers crossed I’m beginning to believe that our chenilles have come down and are now sAfeky underground. Despite several inspections a day, we’ve seen nothing for over a week. How is anyone else getting on? The nests look vile, baggy & full of holes. I think they’re abandoned. Am I being unduly optimistic?
Many thanks,

Thankfully very amenible neighbors and we did the 'Chop and Napalm' method the other week.


I am informed by my distributors that is is now probably too late in the season to treat chenilles processionnaire using biological treatments (Foray 48b) as, another mild winter has advanced their life-cycle. They have probably stopped eating and will begin their processions soon.

So, the only solutions available now are "chop and burn" or "éco pièges" they are available at Gamme Vert and online individually. You will need to check the diameter of each tree and put a piège on each affected tree.

(Ed, please forgive the advertising, but I think this one is important)

I can supply DIY kits [of 10], please PM me for more info, as they are not available in shops.

(end of ad!)

Times of year to treat:

June-September Pheromone traps to catch the male butterflies

Sept- December (Jan max) Chemically spraying the trees (3 litres [non diluted] per hectare). New rules forbid "fogging" (spraying by air) so each tree has to be treated which is time consuming therefore expensive.

The problem each year is people ignore them when they need to be treated as they are "insignificant", then panic when it's too late!


Thanks for the video Rob - I've posted it to my Facebook account asking if anyone does anything similar here in the Dordogne. Now to see how you go about destroying them ! Note to self - must throw away the gloves that I used when dispatching my strings of caterpillars. Each time I use them I itch (obviously !!!)

Here's a video (taken by a local amateur) regarding the treatment of chenilles processionnaire. Please excuse my appalling French, it was cold!

Hope it's useful.


Having recently, see the top of this page, helped clear four nests I would say that like spiders' webs they are tough enough to withstand a fall. However, insects don't really sleep so any disturbance will get them moving. That is why we try to get large, thick paper sacks over the nests then bind them closed and in another sack unless we can burn immediately. Even then we make sure the nests go right into the centre of the fire in case the sack bursts open and they spill out with some getting away from the blaze.

Apparently some marched through a recently built bungalow on the other side of the commune. The wife came out of the bedroom in her slippers, or whatever she wore, and got her feet badly hurt. She is in hospital for at least 10 days because the effect of probably hundreds of hairs from the sound of it did severe damage. Luckily her husband had no problems but had to bundle her and the dog, who is OK, in their car and head for hospital very quickly. One line of them was apparently nearly 40m long in another place so two farmers came out with stubble burners to incinerate as many as they could whilst other people with garden flame throwers did the rest.

Not really - A I dordogne. I sympathise with you and your itches ! I almost kicked the dog and cat out but no its not fleas!! I think the main thing is to try never to itch the rash and break the skin. Yes neck and face and hands/wrist and I suppose avoid employing anyone with a builder's bum !!!!

Over dramatic? I don’t think so! We also got horrendous rashes on our arms, stomach and neck. We didn’t realise they could be from the chenilles, but thought we had bed bugs or something. The pharmacist couldn’t identify them and the anti histamine tablets and cream didn’t help. Despite trying not to itch I was in real pain for ages and had to sit with ice packs against them. We’ll definitely be putting on protective clothing next time. Were there any useful comments on the other forum?

Thanks Roger, we’ve already accepted a devis from our French neighbour to do the job and he’s hoping to come within the next 2 weeks.

Thanks Robert - I’ve just looked up pheromone traps and that looks like a great idea. My husband thinks perhaps getting the eco pièges as well to be doubly sure. It would certainly be good to be able to keep the trees and cost a lot less as well.

Can you tell me how strong the nests are? Just wondering if they’ll break open and release hundreds of caterpillars when they hit the ground - I presume the bloke will try to lower them carefully, but it won’t always be possible of course.

moral, once you have used clothing to remove chenilles, throw them away or wash on a hot wash if possible.

I use disposable boiler suits (combinasions jetable) which you can get online for about 1€ each.

Once the nests are gone, why are you chopping down the trees, the risk will be gone. In the summer put pheromone traps down to attract the adults before they lay nest year's eggs.

Incinerator is a good idea, as are gloves, goggles, and protective clothing.

Hi Wendy,

Our garden had been massively neglected & we used an English tree-surgeon to prune & fell our trees. On our pine he spotted chenille nests hanging down & said what a pig they were to deal with-despite protection still getting itchy skin rashes.

However, he waited for a very cold morning-November for the pruning & felling. He bagged the nests before putting them on the large bonfire. He is based in Dordogne if you want details tho we are 33540.

I cleared up chenilles on 19th December - I still itch. Yesterday I wore the gardening gloves that I must have used to clear my caterpillars. I now have new itchy spots round my wrists for the next 3 weeks. I have read on another forum that we are all being a bit over dramatic about this !!!!

Are we being foolhardy? Our French neighbour, who has a business in landscaping and tree surgery, has offered to cut down the branches where there are cocoons. He has suggested that we get an incinerator, scoop up the fallen chenilles and burn them straight away. Sounds simple but I’m very concerned about the nests falling to the ground (they are up to 25 metres high) and the toxic hairs flying everywhere! We plan to cover the ground with tarpaulin to try and make easier detection of runaways and also to wear full protective clothing, mask and goggles. Once the nests and chenilles are gone we’ll plan to get the 5 trees cut down. Your thoughts would be welcome, thanks.

I was at the mairie today and talked about the caterpillars and about next season's Asian hornets. We have a task force for each, I was roped in because I keep bees and have protective clothing. I have helped recently with a one piece overall under my beekeeper's one piece with not just a net but also a thick plastic vizor and gauntlets over my elbow length beekeeper's gloves. It was a little tree in a neighbour's garden with four nests but the two of us who did that found so many of their hairs on our protective clothing that we had brush each other down with an industrial quality Kaercher vacuum cleaner then take out and burn the bag immediately. This commune has a major infestation, several thousand nests I was told today. The department has said there is not enough money to deal with it all and is now encouraging people to take private action. There is statutory requirement to deal with infestations but not the resources and this spring is insane. If two of us are occupied for an hour and a half getting four nests down and burned but then an hour of that time clearing ourselves of hairs then it is becoming humanly near to impossible to act. Mairies that refuse to take action are defying national regulation to prevent the spread, thus complaints about maires refusing are the first step. Our maire wants to act, but a tiny commune in terms of budget over a large area is a nightmare.

Hugh Tavernner posted on 23 Dec "the Mairie might be able to assist" Good luck with that. I have finally convinced our Mairie to allow me to treat the 50 or so trees affected, after 4 years of trying to convince him.

A post on 22 Dec regarding drones; In my opinion I don't think they will be permitted, as the max wind speed for spraying chenilles is 20Kpm and the up/down draft will be greater than that, as usual it is a grey area!

I'm back from playing on NZ beaches and am now happy to assist via PM if needed.

1st job back, chenilles processionnaire...du chêne!

Meilleurs veux


Easier said than done! and protective clothing including a face mask "should" be worn.

The hairs on the caterpillar are toxic therefore can be dangerous to some animals. Cats generally avoid them whilst some dogs like to play with them.

Branches must be cut down and burned on garden bonfire. These insects are deadly to animals and sometimes even humans.

That's good.

Let's hope for some colder weather to quieten 'em down!