The Deadly Caterpillar of the Pine Processionary Moth
The Caterpillar of the Pine Processionary Moth
In the area of Spain where I live there is a deadly little critter that is a real threat. Though it usually does not prove deadly to people, it almost always does prove to be deadly to dogs. This deadly little critter is the caterpillar of the Pine Processionary Moth.
In late August the female moth lays her eggs on the pine needles. These pine needles will provide the food that the caterpillars will need when they hatch.
The female can lay up to as many as three hundred eggs. This is a lot of eggs but at this stage are really minute. These tiny eggs are all clumped together when she deposits them in a mass on the pine needles on the pine tree.
It takes about a month for the minute caterpillars to hatch. Once hatched they eat and grow quickly.
The caterpillar goes through five growth stages. At the end of each stage it moults its skin to accommodate its new growth. At the stage of it third moult the catterpillar begins to build the communal silken nest. It is these silken nests that you see adorning the pine trees.
The pine tree is their food source and the nest protects them from the cold and wet of the winter months. You will often find more than one of these nests on a pine tree. There can be several hundred caterpillars in a single nest and they can do quite a lot of damage to the tree.
The caterpillars cause damage to the tree by stripping bare the branches. The damage is greatest near their nest as they eat the pine needles voraciously.
A Caterpillar Nest in a Pine Tree
Deadly Little Critters
The caterpillars forage and eat by night and sleep by day. In this way they avoid attack from many of the daytime predators such as the birds and certain types of wasps.
The Pine Processionary moth catterpillar is quite dangerous to both pets and people. The catterpillars have fine hairs that are poisonous. These hairs are part of the defensive mechanism of these caterpillars.
These poisonous hairs are fatal to cats and dogs. In some very rare cases also to people if they are allergic to them.
Even if you are not allergic these hairs if touched can give you a painful rash that can last for days. You can see the hairs quite clearly in the next photograph.
A Close up of the Pine Processionary Caterpillar
We have a dog and on our normal dog walking route there are many Pine Trees. Many of these trees have these nests in them. When we see the nests appearing we go out and try to remove as many as we can.
If we do this before the caterpillars begin to process then we can greatly reduce the danger to our dog. Also as we remove the nest we also reduce the future infestations on our dog walking route to almost zero. Because we have been destroying the nest we have found that each year there are fewer new nests.
Early Spring the nests of these caterpillars are decorating many of the local pine trees. Each one of these nests can house up to several hundred of these caterpillars.
Here are some photos of nests. Click on image to see full size. You will enjoy the photos more if you take the time to look at the full sized image. I uploaded the photos at full resolution so that you can see the fine details.
You can see on the outside of the nests that there are some full grown caterpillars already out of their nest.
A nest of the Pine Processionary Caterpillar
They call these caterpillars Processionary because that is what they do. At the end of their 5th and final growth stage as a caterpillar they form a procession.
These processions take pace, when they go searching for a suitable site to pupate in. When the caterpillars set off to search it is always in a procession. At the right time of year you can see many of these processions. The caterpillars walk in a nose to tail procession following a leader.
The caterpillars are searching for soft soil that they can burrow into. They burrow to pupate ready for the next stage of their lifecycle. Once they find a suitable site they burrow in. There underground they will change into a pupae. They will remain buried underground until they emerge the next summer. They live out the final part of their lifecycle as a Pine Processional moth.
The processions take place from the middle to late February until about the middle of April. During this time great care has to be taken with your dogs. The last thing you want is for your dog to come into contact with the caterpillars.
During these months when the caterpillars are processing we never let our dog off his lead. As vigilant as we are at removing all the nests that we can see we still can come across these caterpillars.
The caterpillars normally build their nests on the side of the tree that faces the sun. This makes the location of the nests a little simpler. Once we have located a nest we cut it off the tree and place it in a carrier bag.
It is important when doing this to take precautions. The hairs of these caterpillars can cause some very nasty rashes. These can take some time to heal and can be very sore and itchy.
You especially don’t want to inhale these hairs or have them get into your eyes. Rubber gloves are a must as you don’t want any of these hairs to come into contact with your skin.
Cutting the Nests from the Pine Trees
Making the Place safe for dogs
If you have an infestation of these nests near you information on the web says to contact the Guardia Civil. The Guardia will then arrange for their removal. Resources that both the Guardia and the local Ajuntamenta have are extremely limited. Because of this they often do nothing.
Opinions differ about whether you should remove the nests yourselves. But we really can’t risk the health of our dog as he is a much loved family pet and to us irreplaceable.
Because these caterpillars are so dangerous to dogs we go out and remove as many of their nests as we can. We remove as much risk as we can, and we know we are not alone as other pet owners do the same for the same reasons.
Trying to make our part of the world a safer place
I hope you enjoyed the photographs of our attempts to make our part of the world a little safer for the dogs of our area.
Insect based Hubs
If you enjoyed this Hub you might like my other insect based Hubs.
- The Life Cycle of the Dragonfly - In this hub I want to look at the life cycle of the Dragonfly and I suppose that the best place to start is at the very beginning. This is where it all begins;
- The Cicada - The Cicada is a member of the order Homoptera and the noise that just one of these creatures can make is amazing. The name cicada actually comes from the Latin word for buzzer. It is the male of this species that makes the loud clicking and buzzing noise by vibrating membranes on their abdomens.
- The Caterpillar of the Pine Processionary Moth - In the area of Spain where I live there is a pesky little critter that is a real nuisance at this time of year it is the caterpillar of the Pine Processionary Moth.