Ooerrr...........are they around in this country (UK) or just France & Spain?
It is important to point out (I think) that they are only a problem at certain times of the year. The nests were in the trees late Nov and Dec when we travelled last year, they look like cotton wool.........it is when they leave the nests I think when the problems occur.........can someone confirm the times of year that they are the biggest problem.
We can vouch for their danger! The already mentioned George our Jack Russell only sniffed one and the whole of his face swelled up and he was violently sick. This was one winter in Portugal. We managed to speak to a vet in Faro who told us to keep an eye on him and luckily for us he recovered.
We are now very weary of them, giving them a wide berth if we see any.
The only good thing about the very wet winter we had this year in Portugal was that the little blighters must have drowned as we did not see any!!!!
what a fascinating post! Having camped on a pine forested site in spain, for many years, in the summer ( way after the capterpillars have evolved) we have seen the nests, and had the warnings about walking barefoot etc., but didn't realise just how nasty these critters are! And your photos are stunning! Thank you