processionary caterpillars
 

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.

Re: processionary caterpillars
 

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 :unsure:

PS - what pesticide did you use?

Re: processionary caterpillars
 

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 ?

Re: processionary caterpillars
 

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.

Re: processionary caterpillars
 

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 :(

Re: processionary caterpillars
 

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

Re: processionary caterpillars
 

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.

Re: processionary caterpillars
 

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

Re: processionary caterpillars
 

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.

Re: processionary caterpillars
 

And if people stopped keeping cats

Re: processionary caterpillars
 

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.

Re: processionary caterpillars
 

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

Re: processionary caterpillars
 

Is that for real?:rofl:
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

Re: processionary caterpillars
 

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.

Re: processionary caterpillars
 

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.

Re: processionary caterpillars
 

Some pictues of my small pines with nests I killed, and one in a high tree I didn't.
I thought I had pictures of the bark beetles too, but I can't find them now.
https://cimg4.ibsrv.net/gimg/british...15a924d8b6.jpg
https://cimg5.ibsrv.net/gimg/british...7d81515eba.jpg
https://cimg6.ibsrv.net/gimg/british...ac11fac80c.jpg
https://cimg7.ibsrv.net/gimg/british...6dedb0f446.jpg
https://cimg8.ibsrv.net/gimg/british...d1ffaeb9bb.jpg
https://cimg9.ibsrv.net/gimg/british...2501dfec88.jpg
https://cimg0.ibsrv.net/gimg/british...aa43c21a6e.jpg

Re: processionary caterpillars
 

Yes it is for real-whole roads would be closed in the early morning and they would get a good blasting then sprayed and a road sweeping lorry would suck them all up and take them off for a mass bonfire-the Italians love a bit of drama

Re: processionary caterpillars
 

The active ingredient in that insecticide is Cipermethrin (Cipermetrina in Portuguese). You can buy that from Sanipina in Lagoa or ADP in Portimāo (opposite Aqua next to GLS), it's behind the counter so you have to ask. Dilute in a sprayer with water and away you go.

Re: processionary caterpillars
 

Is the license required ?

Re: processionary caterpillars
 

I've never been asked for one. I bought from both places last year. I use the same product in a home made fertigator to control ants on a lawn.

Re: processionary caterpillars
 

Went to Lagoa today but Sanipini wouldn,t play ball - certificate required.
ADP however were extremely helpful and fixed me up
Enquired about doing the course to get the certificate - 140€ 5 consecutive Saturdays all day and an exam at the end Hmmm.
Anyway, thanks for the heads up Score76, lets hope ADP continue to accommodate !

Re: processionary caterpillars
 

Only in Portuguese I was told, so you'd have to be reasonably fluent.

ADP; I'll have to remember that for when my supply runs out.
That will only be in a few years though.

Re: processionary caterpillars
 

When should these caterpillars stop their marching?

Re: processionary caterpillars
 

When they find somewhere to pupate.

Then a bit later on you can have a whole new batch of adults to start the cycle again..........

Re: processionary caterpillars
 

Also, the final exam is a written one - in Portuguese !
However, over 75,s are exempt and can get a certificate without doing the course.

Re: processionary caterpillars
 

At one of my drogerias I can buy insecticides without a license or certificate. I obviously look over 75 and therefore not worth saving.

Re: processionary caterpillars
 

https://www.portugalresident.com/hol...c-caterpillar/

But is the pesticide worse?

Re: processionary caterpillars
 

Re: processionary caterpillars
 

Type size used to be on the band above the message but it is no longer there so I could not change it for you.

Rosemary

Re: processionary caterpillars
 

Where we are (Netherlands) they tend to nest on the trunk of Oak trees which are plentiful alongside roadways and paths.
Here, the council now has a spray machine on a trailer towed behind a tractor. They treat the trees in the spring as the problem has got so big.
Even so, we get warned each year if they are around.
As the weather warms up the caterpillars become active and could be seen in large squirming groups most often 8 - 10 m up.
The spraying has helped reduce the problem somewhat.
We used to walk our dogs a few years ago and they would be hanging down on silken strands waiting to drop onto your head or around your face..glad we don't see that any more.

Re: processionary caterpillars
 

The Oak processionaries got to the UK a few years ago too - I think there were reports from one of London's parks (of course that's when it officially becomes a problem in the UK - when London is affected)
I know they are different species but the problem is the same
I would like to cut the rest of our pines down, but cost and wife's childhood memories of a house in a forest the 70's stop this for the moment
Ours are now just a 'mushroom' in the landscape - everyone else cut them all down on purchase of plot or existing house - it not a forest any more for sure
This also means they have no protection from the winds and no neighbours to make a root carpet

Re: processionary caterpillars
 

I used to have conifers in the garden, also as a wind barrier. For keeping insects at bay I used a homemade remedy of a few squirts of washing up liquid with water in a 5L sprayer with a capful or two of bleach.
Don't know if it would work for the caterpillars. It certainly kept the midges, ants and ticks out of my trees.

Re: processionary caterpillars
 

Many people cut off the nests and bury or burn them; of course it depends on your ability to reach them.
Also, it seems a bit dangerous to me, but I guess it's ok so long as you're careful.

If you don't like synthetic pesticides, you could try the "organic" ones to find out if they work.

I found neem pesticide to be very effective on other pests; it's a bit expensive and the shelf life after the bottle is opened is rather short.

Depending on the size and quantity of trees, you might be able to have them harvested. They'll even pay you for the wood.

I was offered 1000 euros for my forest; 25 years of growth, 1/2 hectare, so that's 40 per year pure profit. I respectfully declined.

Re: processionary caterpillars
 

There is always the trusty Karcher pressure washer too...

Re: processionary caterpillars
 

I don't think that would be a good idea; you'd just blast them all over the place.
I don't quite believe that news article about the guys who were hospitalized because of them; one person could have an extreme reaction, but 2 friends both had extreme reactions?
Anyway, they are dangerous.

In my case, many nests are 20 meters up; maybe I could get a pesticide nozzle that high, but even that would be quite a challenge.

I notice many of the nests I can see on other properties around here seem to be empty already, so I guess some processions have occurred already.
My severely eaten small trees may be recovering.

Re: processionary caterpillars
 

As crazy as this suggestion seems I've seen it done. Some of the jet washers have the little tube you can drop into a container of detergent for soaping up the car. I've seen Portuguese using this to mix in both pesticide for blasting the caterpillar balls when they're high up a tree and hypochlorite for cleaning off the dirty black guk from tiled roofs. Pretty sure either will invalidate any warranty but very effective.

Re: processionary caterpillars
 

Good grief!
I've seen a lot of things done here that I wouldn't do, or even stand around and watch from a great distance
That seems madness - do not try this at home!

I wear a paper hoodie-suit when cutting them down - like something out of the X Files


I had been starting to get weals from hairs just floating in the air over the last week (I'm ginger so especially sensitive, but luckily don't suffer from respiratório reactions if I am careful) and then I caught my first procession coming down and on the floor yesterday - it was sunny and warm.
Try going out at night with a flashlight and watch the air sparkle
When they come down will depend on your weather over the last 6(?) months and latitude, microclimate etc

I avoid hanging washing outside and opening windows downwind of trees

And the hairs can stay active for up to 5 years (I read that in a Sci Journal, but cant remember where)

And beware the dead last seasons nests which blow down throughout the following year


PS:I have found this great for aphids and things but I am pretty sure, given the strength of the chemicals advised for processionaries, that it will not have any effect on these beasities

How to Make Insecticidal Soap
Combine one cup (or 1/3 Cup) of oil, any variety, such as vegetable, peanut, corn, soybean, etc. with one tablespoon of dishwashing liquid or other “pure” soap. Be sure to avoid any dish washing liquids which contain degreaser, bleach, or those that are for an automatic dishwasher.

Mix two teaspoons (or 1 teaspoon) of this “soap” mixture to every cup of warm water and put into a spray bottle. Mix only what is needed for a one-day application.

1 cup is 250 ml

1 tablespoon is 15 ml

1 teaspoon is 5 ml

1/3 Dose is 85 ml oil with 5 ml fairy liquid. (1/3 Cup + 1 teaspoon)

Re: processionary caterpillars
 

One time I put a pesticide solution into a water type fire extinguisher, pressurized it to 10 bar, and With the aid of a 6 meter long tube on top of the loader of my tractor, managed to get the mix around 15 meters up.

The problem is dispersal; the steam just won't stay together for more than a few meters, then it widens out into fine droplets that rapidly lose velocity.

My conclusion is that the only way to get pesticide into high nests is with something that can actually reach that high, or almost that high.

It's probably more realistic to catch them on the way down. But I have more than 100 tall trees!

Re: processionary caterpillars
 

ooooofff! 100!
I think you have to just live and let live
It has to be every year as they fly kilometres

Some links I found ages ago:

https://www.sciencedirect.com/scienc...264?via%3Dihub

https://run.unl.pt/bitstream/10362/1...entel_2004.pdf

https://www.fao.org/3/a0789e/a0789e13.htm

https://fyi.extension.wisc.edu/spong...ier-band-trap/

https://pigletinportugal.com/2010/11...ars/#more-1057

https://en.wikipedia.org/wiki/Pine_processionary



https://www.naturalhistorymag.com/ht...8_feature.html
(no longer up, but I clipped the following to my Joplin Notes)
Surprisingly, few of the victims in the outbreaks actually touched or saw the caterpillars. The hairs can be unavoidable on a windy day, floating invisibly in the air for more than a mile. High concentrations of the airborne hairs are common because the caterpillars live in large sibling groups—often of a hundred or more—and can achieve high population densities. The caterpillars move about in head-to-tail bodily contact, forming snakelike lines as long as twenty feet, a peculiar form of collective locomotion termed processioning. While this is an effective means of staying together, brazen marches render the insects conspicuous to predators, requiring strong defense against attack. Hence, the hairs—lots of them.
People all over the world have come into contact with the dozens of species of processionaries that have evolved around the world. In West Africa, for instance, inhabitants have eaten the Anaphe caterpillar for many generations. They deal with the hairs by singeing them as the caterpillars are roasted over a fire. Eating one or two of the tasty caterpillars is of no concern. But making regular meals of them, it turns out, often leads to serious symptoms: difficulty in speaking, impaired consciousness, rolling eyes, staggering, and tremors. Only recently has it been established that thiaminase, an enzyme in the caterpillar’s body, destroys the victim’s vitamin B1. The resultant vitamin deficiency, now known as seasonal ataxia, was responsible for about 70 percent of?hospital admissions in Ikare, Nigeria, in August 1993. Fortunately, the symptoms disappear quickly with vitamin supplements.

The most dangerous of the processionaries is the South American Lonomia. In Brazil, a seventy-year-old woman suddenly fell into a coma after she placed a slipper on her foot. Hidden within was a Lonomia caterpillar. Doctors found lesions on her left foot where hairs had penetrated her skin. The toxin had triggered intracerebral hemorrhages, from which she died seven days later. More and more people are being exposed to the hazard because of deforestation and a decline in the caterpillar’s natural enemies. An antilonomic serum, if injected in a timely manner, can save victims’ lives.




Larvae of the processionary genus Hylesia

Central America has suffered in recent years from female moths in the processionary genus Hylesia. The moth, like that of some other species of processionaries, has poisonous spicules on its abdomen, allowing it to carry on the nasty business of its childhood. In 2005, Trinidad shut down offshore oil rigs when the moths fluttered about lights that burned through the night; the spicules broke from their abdomens, drifted invisibly through the air, and fell onto the exposed skin of the victims.

Animals as well as humans fall victim to processionaries. Veterinarians are accustomed to treating curious pets that molest caterpillar processions or nests; the unfortunate animals often suffer necrosis of their tongues, requiring that affected parts be cut out to save their lives. In Australia, the processionary Ochrogaster is the prime suspect in a recent rash of aborted foals: there is growing evidence that if pregnant mares ingest fragments of hairs left behind as the caterpillars march over the ground, their fetuses may die. Although the exact mechanism remains uncertain, the hairs may irritate the mare’s gut, which allows pathogenic bacteria to invade the bloodstream.

While it is mostly because of their impact on human health that processionaries have attracted the attention of scientists, I was drawn to them for a wholly different reason. My interest was piqued after reading a series of essays on the pine processionary caterpillar (Thaumetopoea pityocampa) written more than a hundred years ago by the renowned French naturalist Jean-Henri Fabre. Fabre conducted remarkably detailed studies of the larva and the moth, which he recorded in his encyclopedic ten-volume Souvenirs Entomologiques.

In January 1896, Fabre wondered what would happen if the first caterpillar in a procession could be made to follow the last, creating a complete circle. He soon had his answer, for by chance a procession crawled onto a palm pot in his greenhouse and formed a circular procession around its rim. To his amazement the caterpillars circled for seven days before breaking free. Factoring in rest breaks during the cold nights, Fabre calculated, conservatively, that the caterpillars marched for eighty-four hours, circling the rim 335 times. He attributed the circling behavior to blind instinct, stating that the caterpillars lacked “the rudimentary glimmers of reason that would advise them to abandon it.” His account of the circling procession is one of the best known of all insect stories, because it is viewed as a metaphor for mindless living. The story has been endlessly retold by inspirational speakers who see in it the folly of blindly following the crowd, striking off with neither a goal nor a leader, or confusing activity with progress.

I pondered Fabre’s account, not from the point of view of one searching for inspiration, but from that of a scientist who had spent nearly all of?his working years investigating the behavioral and chemical ecology of social caterpillars. In truth, I doubted that caterpillars could be endlessly trapped in a circular procession merely because they adhered to an instinct to follow each other; something else was at work here. I also wondered, as had Fabre, how the caterpillars managed to form and maintain processions in the first place. Fabre observed that each caterpillar lays down a fine thread of silk as it marches along. Although he never formally tested his hypothesis, he felt that the caterpillars sensed those strands, leading them to trail one behind the other. Fabre was an acute observer, but he died long before the discovery of the role of pheromones in orchestrating the collective behavior of social insects. My research with other species of social caterpillars suggested that a previously undetected pheromone might be essential to the formation of processions. Thus, I set off on a study of the behavioral ecology of the pine processionary, which lives in southern Europe and northern Africa.

When I initiated my investigation, I was fully aware of the caterpillar’s toxic nature. Insatiable experimenter that he was, Fabre reported that he suffered severe rashes when he poured extracts of the caterpillar onto his skin. One of his contemporaries, attempting a similar experiment, experienced a much more dangerous anaphylactic response and reported that “not only my hands, my arms, my legs, but my whole body became the seat of insupportable itching; soon my face swelled, my eyes puffed up and I had to give up writing my remarks.” After suffering a severe conjunctivitis when a tiny fragment of a caterpillar’s hair fell onto my eye, I found it necessary to move with caution in the field and to confine the caterpillars in my laboratory to a room fitted with air filters. Nonetheless, there were few days during my studies when I didn’t have to deal with an itching dermatitis.




Baby pine processionaries



Pine processionary nest

I conducted my field studies in Catalonia, Spain, where the life cycle of the pine processionary begins in early August, when the moth lays up to 300 or so eggs on pine needles. Soon after they hatch, the tiny caterpillars construct a flimsy silk nest around a few pine needles. That nest is abandoned after a short while, and over the next month the caterpillars collectively build a succession of nests at new sites in the branches of the tree. Their nomadic nesting habits end after their second molt, when they initiate the construction of a dense and virtually impenetrable silk nest they will inhabit for the rest of their larval lives. The permanent nest stands apart from the caterpillar’s food supply, and they march from it to feeding sites on the host tree, returning home hours later with full guts. It is with the initiation of the permanent nest and the long marches that the caterpillars’ hairs, until now soft and harmless, grow into stiff, toxic bristles. Their nest becomes littered with those bristles, fortifying it against attack by would-be predators.
A striking feature of the pine processionary’s life cycle is that the insect spends the winter in the caterpillar stage. Since insects are ectothermic, producing no body heat, one would expect that they would lie immobilized in their nests on cold winter days. To determine how the caterpillars fared during winter, I set up activity monitors near nests in mid-February. The monitors projected invisible infrared beams across pathways the caterpillars used when they foraged. When the beam was interrupted by a passing caterpillar, the signal was sent to a data logger, time-stamped, and later uploaded to a computer for analysis.

During the week of my study, temperatures in the afternoon reached average highs of 63 degrees Fahrenheit, but plummeted rapidly to below freezing after sunset. Yet the monitors revealed that the caterpillars only left their nests after dark and returned before dawn. One morning I observed that water had turned to ice in a pot left outside overnight, and I was sure I would find that the caterpillars had spent the previous night snug in their nests. But the data loggers revealed that they had been active outside their nests until the temperature dropped below 28 degrees, at which point they became immobilized. As soon as the first rays of the morning sun struck them, their bodies warmed, allowing them to make their way back to the nest, and by 9 a.m. all were home.

The study revealed that the caterpillar has one of the lowest “chill-coma” temperatures (the temperature when all activity ceases) ever documented for an insect. It is likely that selection pressure from daytime predators accounts for that seemingly strange behavior. For not all predators are put off by the pine processionary’s toxicity. Remarkably, the hoopoe, the great tit, and the great spotted cuckoo are all able to feed on the caterpillars without ill effect.

Although the nest serves as a secure retreat, it has another equally essential function. During sunny days, it traps solar radiation. Thermo-sensitive probes I placed in nests in February registered as high as 100 degrees during the day. Heat trapping warms the caterpillars enough during even the coldest days to enable them to efficiently metabolize the food they’ve collected during their nightly forays.

In early March the caterpillars take their last meal, an event followed by a grand procession. Up to now they have confined their forays to the host tree, but on this occasion they march down to the base of the tree and set off over the ground in a snaking procession. The leader advances, goaded on by the mass of caterpillars that push from behind. The caterpillars are in search of a place to spin their cocoons. Along the way they test the ground, seeking loose soil, and eventually they bury themselves side by side several inches underground to undergo metamorphosis. The timing is right because the nests would be much too hot to occupy in the torrid summers that characterize much of their range. The pupating processionaries stay underground until August, when, as moths, they burrow up through the soil [see illustration below]. Children who uncover one of the communal crypts while digging in sand in the summer become inadvertent victims of the caterpillars’ hairs. The abandoned nests, too, continue to spew toxic particles into the air well into the summer.

Re: processionary caterpillars
 

Wow; after reading that, you start to think that maybe forest fires have a bright side to them.