There seem to be many this year; I have nests in many of my young pine trees. They seem to prefer the young pines to the big older ones.

They eat the pine needles at night and retreat to the nests in the day, before eventually venturing forth (in procession) to lay eggs.
Some trees look dead.

As is widely reported, these creatures are highly toxic to humans and animals, and should be avoided. On the other hand, the nests need to be dealt with if you have them in your trees.

As the nests were all low in my place, I was able to spray them (around 150 nests) with pesticide; now I have 10,000 dead caterpillars, but I guess that's better than 10,000 live ones.

There are strategies for higher nests, you have to wrap the tree trunk in some particular way.

Anyway, be careful in forests, especially when walking your dogs.

SWMBO has said the nests in the pines close to our house are really heavy this year and I can't get back to deal with them...... I've suggested she gets someone in to remove them and to cut back the pines, as they are growing too tall.

The only problem is finding someone capable, willing an available. Sadly, these days, most of those fitting those requirements would rather sit in the taberna

PS - what pesticide did you use?

Yes, we have no pines but see lots of nests in neighboring trees. Off out today, to find some of that yellow tape to put around the closest trees to try and reduce the invasion.
I,ve also noticed that several pines have died back this year ? Anything to do with these bugs or something else ?

There are 2 bugs that I know of that are killing my pines; the caterpillars eat the needles, and seem to kill smaller trees that are infested.
Then there are the bark beetles; they eat the flesh between the bark and the wood. Usually they live in the trees without killing them, but when the trees are stressed they can't produce enough turpentine to keep the bugs at bay.
You can see the holes in the bark as the tree dies.
I cut up many of the dead trees, some I let dry first, then the bugs eat tunnels into the wood as it dries out.
I sliced up a few while they were still wet, there was a strong (pleasant) smell of pine and no bug tunnels into the wood. I got some usable timber, but of course the boards twist up pretty bad as the dry out.

I used a pesticide called "destroyer" that I bought years ago, before the licence requirement. I can check the compound name if you want.
It was very effective, just a squirt of 1% solution onto the nest killed them all.

Thanks, the compound name would be useful - it may still be available.

So far, in under 10 years I have lost all my palm trees (4) due to the imported beetle, now I am losing all my piteiras, due to imported beetle. The pine trees are a worry as they're within my property (faily close to the house) and an area where my dogs like to go..... until now we have cut out the nests and destroyed the caterpillars, but las year SWMBO was affected, despite gearing up, and now the trees are gtting too big for us to deal with them

I have a dog. Are these caterpillars out now? I thought it was from March.

It will depend on the weather, they don't use calendars.

If the nests are swollen now, it suggests that the caterpillars are well developed - and once they start to break out, it'll be too late.

Maybe if "hunting" was stopped completely, it would give bird life a decent chance to multiply and they control the caterpillar population

Maybe, but the processionary caterpillar has long been a problem in Iberia. It's relative, the oak processionary caterpillar is now becoming a problem in the UK...... so maybe climate, not hunting.

And if people stopped keeping cats

I seriously doubt a sustainable bird population could eat enough of the caterpillars to make a difference; they only come out at night (to avoid predation) until their migratory procession.
Then there are too many at once.

In reality, these things are successful natural creatures; it just so happens that we humans and our pets don't like them.

I'll post some pictures tomorrow, and the info on the pesticide.

In Italy the local authority employed the hunt to blast the nests out of the trees with shotguns and then sprayed them with pesticide when they hit the ground

Is that for real?
thereby dispersing the millions of hairs into the air and all over the property (they stay active for up to 5 years)
I like their style tho!

There are only very few species of birds that can eat them

I have found the best way is to cut the nests down and burn them with alcohol on the floor when you can reach them (I use one of those pole pruners duct-tapped to a windsurf mast to get as many as I can)
This also woks if you find a procession, before they can dig into the earth and pupaet
Have a hose ready!

Any individuals I find fallen on the floor I carefully put in a jam jar of alcohol using BBQ tongs

They generally come down around when we get that yellow snow of pollen from the trees (although they can get blown down at any time and will then climb up the nearest tree or wall or whatever)

You can get the trees injected to kill them as they eat the needles, but that has to be done before and is around 100 a tree, each year ......

The Brazilian tree 'surgeons' (more in the sense of the rum and bite on this stick) will go up a tree here and cut them down for you too

I have tried the traps using burlap - no luck

Dont try putting grease around trunk as I read on 'tinternet and tried

In the end, around that time of year, Salty is not allowed out of the patios into the wider garden, but I have to be vigilant, and out on walks

Also, the old nests blow down in the winter and they are full of hairs, so you need to keep an eye out for them too

Horrible things, as a pale skinned ginger I suffered immensely cleaning out the previously unkept pinheiro garden

For your pets, keep a supply of normal for human cetirizine at hand and at any of the signs feed them to your dog and get STRAIGHT to the vets

The pinho-brave get so tall anyway that we will get them taken out, and since this area is no longer a forest there are effectively only individual trees so the 'root carpet' stabilizing effect has been lost and they are even more prone to windfall

I've spotted some nests in my tall trees too; they're 20 meters or more high (I need to take measurements with a sextant sort of thing).
How to get at them is tickling my brain... it's really quite difficult. Maybe I have to let (hope) the birds eat those.

My trees are pinheiro manso and no taller than 5-6 metres...... that's why I want them cropped as well as having the bichos dealt with.