The dreaded procession
Advice on keeping the processionary caterpillar away from your garden and pets
By Shelley Liddell IF YOU are lucky enough to have pine trees in or near your garden, then it’s likely that at some point you would have to deal with a processionary caterpillar nest, or see the caterpillars treck single file across accross the ground.
To be able to eliminate them, it helps to have more information about them, so read on…
Caterpillar life cycle The processionary caterpillar is part of the moth family. During its short life as a caterpillar it passes through five stages of growth, starting at stage one (26mm) and ending at stage five (25-40mm).
It shows its typical appearance of abundant brown spiky hairs and orange spots when it reaches stage three during autumn and winter; this is when they form the typical white nests that can be seen in the pine trees.
It is now, at the end of winter and beginning of spring, that they descend from their nests and form their characteristic march, head to tail, before burying themselves in the earth to emerge as a moth during the summer months. The moths mate, lay their eggs and around a month and a half later the caterpillars are born.
Methods of control The best way to avoid them at home are:
Eliminating eggs. It's possible to remove the eggs manually during August, September and October from small trees before the caterpillars are born.
Eliminating nests from November to March. Cut the branch with the nest, introduce into a plastic bag and dispose of it. Platforms or extending pruning shears can be used for larger trees. Protective clothing should be used and permission obtained from the town hall if the nests are burnt.
Physical barriers in or around the tree to stop the caterpillars reaching the ground from December to end of April.
Encourage birds and bats to nest in the tree by hanging nesting boxes, as they are the caterpillar’s' natural predator. This can be done all year round.
Use a pheromone trap in the summer to trap male moths. These are installed during the moths' mating season, from June to October. They can be obtained from most agricultural association ‘cooperativas’, garden centres or farm animal feed shops.
There is a pesticide Diflubenzuron that can be applied from October to December that will kill them off at stages 1-3 of their growth. A microbiological insecticide (Bacillus thuringiensis kurstaki) can also be used at the same stages. Only people in possession of the appropriate licence to use these insecticides can purchase them.
The aim is to avoid them coming into contact with people and pets, but not to totally eradicate them, as few people realise that they are a vital part of the area's ecosystems, being an important food source for birds and bats…
Although pine trees affected by them turn brown and look as if they are dying off, they are actually unharmed and will sprout their full greenery again come next spring.
Dangerous to pets and humans They are extremely dangerous to dogs, and can cause death in some cases. Keep dogs away from
caterpillars It is the caterpillar's hairs that cause the damage, as they are extremely irritating. If a dog swallows or inhales hair they can die due to their airways swelling to the point that they are obstructed.
Caterpillars lose their hair as they move and they can be COSTA NEWS, March 16-22, 2018 blown around in the wind, affecting humans and dogs alike
A few tips if you have dogs:
Avoid walking near pine trees from the end of winter to the middle of spring.
If you have no choice but to walk your dog near pine trees with nests, make sure your dog wears a muzzle. Avoid walking in the area at night, as this is when the caterpillars are most active. Make sure you wear long sleeves and trousers.
Inform local authorities if you see caterpillars in public areas, dog parks, etc. Alert your neighbours and use social media to warn people.
Remove nests from your garden as described in this article.
Symptoms in pets Pets can be affected in any part of their bodies, but it’s usually the mouth area that comes into contact with the caterpillar or their hair. The first symptoms include:
Intense itching. The dog might be pawing at his face if his eyes have been in contact with hairs
Swollen head, muzzle, eyelids, tongue and/or throat
Excessive salivation and panting Irritated skin Vomiting. If your dog presents these symptoms, flush the affected area with saline solution, fizzy water or tap water without rubbing and take him to the vet immediately. In some cases the dog can die due to anaphylactic shock and may end up losing part of his tongue due to necrosis.
If you live in a remote area or do a lot of mountain walking with your dog, ask your vet for a prescription of Urbason (Methylprednisolone) and how to use it. Urbason is a fast-acting corticosteriod, and it could keep your dog alive long enough for you to get to the vet.
Symptoms in people Adults and children who are allergic to the caterpillars should take special care over the next few months, as they are coming out of their nests looking for food.
Humans are usually affected either by direct contact with the caterpillar or by their hairs floating in the air. Symptoms are severe itching on uncovered areas like arms and neck, unless they are allergic to the hairs, in which case they could go into anaphylactic shock.
It is important not to rub the area, and even more important not to rub your eyes, as the hairs can transfer to your eyes off your fingers.
Again, wash the area with saline solution. Cold water can also be used.
Any over-the-counter antiinflammatory medication can be used, and if the itching does not subside, visit your doctor, who will prescribe an appropriate treatment. Usually the itching lasts a maximum of 24 hours.
Some people can suffer a severe allergic reaction to the caterpillars, so it’s advisable to cover up with long sleeves and a scarf and protective glasses if you go mountain walking in pine forests.