A Little Background Information.
They are known as processionary caterpillars as the form a long, nose to tail procession, in search of soft ground to bury themselves in, and pupate into moths. These processions are formed when they leave their cocoon, high in a host pine tree. They are common throughout warmer areas of Southern Europe.
The Lifecycle
Adult moths lay their eggs near the top of pine trees. After hatching, the larvae feed on pine needles as they develop, and can cause significant damage to some trees. They build a silken nest to protect themselves during the winter months. They leave their nests soon after sunset and feed on the branches of host tree, returning to the nest at sunrise. They rest during the day and the heat from the sun helps them develop and grow. They remain in the tree until they are fully grown from January to March - though this can vary depending on winter temperatures affecting growth - and begin their march, down from the tree in search of soft ground to bury themselves. After pupation they emerge from the ground towards the end of summer as a fully grown processionary moth.
During their search for soft ground, they form processions with up to 300 caterpillars, nose to tail. Their natural defense system is in the very fine hairs, which contain an extremely potent irritant, that can cause severe rashes on human skin. When threatened, they can also eject these hairs which have a tiny hook on the end making them difficult to dislodge.
Dogs and Cats can be particularily curious, both by the caterpillars appearance and their bittersweet smell and contact with the caterpillars can cause severe reactions - and even death.
These generally appear around December or January, though can be earlier depending on climate conditions. They have a silk/cotton wool appearance and are very often on the south side of the tree, as the caterpillars require warmth to grow. They very often return to the same tree and if you have a number of pine trees on your property you will generally see the same one or two trees affected. The nest is about the size of a small melon. They leave the nest at night to feed, usually on the host tree, and return before dawn. But be warned, they can decend from the tree in search of food, so if you have a nest nearby, be careful when letting out pets after dark.
If the nest is not too high, it can be sprayed with an insecticide such as Decis (made by Bayer, available in most garden centres and Leroy Merlin) or ordinary household bleach. Long handled pruners can also be used to cut the branch the nest is on. Some people suggest burning the nest, but be warned, this can allow the hairs to escape into the air. If you do cut the nest down, spray it heavily with hairspray to contain any of the hairs and place it in a bucket of bleach.
Do not carry out either of the above without ensuring you have no exposed skin. Wear gloves, mask and eye protection. The hairs are major irritants.
You can place traps around the tree to stop them reaching the ground. They are placed approximately 2 metres above ground level. It is a plastic collar fixed to dense foam and creates a route around the trunk forcing the caterpillars around, until they drop through the pipe into the bag suspended below. When you have captured them all, dispose of the bag.
One Campoverde resident I know has used this effectively on a problem tree and captured all the caterpillars two years in a row.
These traps can be removed after the 'marching season' and re-used. Spare bags are available.
Caterpillar Traps.
These are only needed for trees with nests, so if you have a number of pine trees, only those with the nests require the traps.
We have found a supplier in Murcia offering the traps at a much lower price than elsewhere, but they must be purchased in multiples of 10 units.
N.B. These traps are for trees up tp 130cm in circumferance. Larger trees will require 2 traps to put together.
If you want to see how they are installed, click here There is a video halfway down the page.
They generally leave the nest around February or March, though it can be earlier in a mild winter. The march can have up to 300 caterpillars, and can be 3-4 metres long. They are blind and march nose to tail. As they are nocturnal, they tend to be more active in commencing their march early morning, so it is good practice to walk around your property in the morning before letting pets out, but they can be seen at other times of the day as they search for suitable ground to pupate.
Just because you may not have trees on your property does not mean you will not see them in your garden, they quite happily climb walls in their search of soft ground to bury themselves. Last year I found 3 seperate marches, one climbing over our wall from my neighbour, one in the garden from a tree now trimmed back and the other marching up the road outside our house.
If you have a caterpillar march on your property you need to eliminate it as soon as possible to avoid contact with pets, particularly dogs which may sniff, lick or even try to eat them. My kit contains the following:
Bucket, pan and brush, large can of hairspray, large bottle of bleach, gloves, mask and eye protectors. I keep it easily accessible during the caterpillar season.
Spray the line heavily with hairspray, stating from the leader and work along the line. They will stop and start to curl up. The hairspray stick the hairs to their bodies. Sweep them up and drop them in the bucket with bleach. They will soon pass on to caterpillar heaven. All can be purchased from your local Chinese supermarket for very little cost.
Wear gloves, mask and eye protection when near them. Remember, their hairs are a major irritant to humans and can be lethal to pets.
I have heard of people using garden flamethrowers on them, but be wary, it can cause the hairs to fly up, and others use Agua Fuerte instead of bleach. It certainly works, but it is Hydrochloric Acid, and undiluted can cause pets paws to burn.
You may also get a small quantity of steroid tablets (prednisolone) from your vet at your next routine visit. Keep these to hand during caterpillar season.
If your pet is in contact with a caterpillar, the animal will quickly go into a state of panic. Act quickly, several pets die from this every year.
Rinse out their mouth with warm water, whist wearing gloves so you do not pick up the hairs yourself. If possible give your pet a prednisolone table, though if the infection is in the mouth, this may be difficult and contact your vet immediately, the numbers are below.
They will give your pet a steroid and possibly antibiotic injections.
Local vet emegency numbers in Pinar de Camopverde are:
Clínica Veterinaria Pelo Picó Pata (near the village square)
966 76 35 63
Clínica Veterinaria
del Sureste (next to Danny's Bar and Grill)
965 35 24 38 Emergency Number: 630 99 47 44
Moby Dick - Pilar de la Horadada
633 027 980
The moths generally return to the same tree they were born in and you will see the same trees each year with nests.
By trapping them as they try to leave the tree can break the cycle though experience says that it may take a couple of years to be successful.
You can also use a Pheromone trap, shown here. The trap has a small phial of pheromone inside which attract the male moth and kills them. By removing the males, the females cannot breed and lay their eggs. They should be hung close to previously infected trees from early June to late September.
The trap and Pheromones are available individually from Econex in Murcia.
Please click here for the product information
