The Processionary Caterpillar

THE PROCESSIONARY CATERPILLAR

If you move to a Pine Tree region of Spain then you will most definitely come across the Pine Processionary Caterpillar. (See Fig. 1) Processionary Caterpillars are so called because they form processions, nose to tail, as they leave the nest prior to changing into moths.  Round about November you will begin to notice what look like balls of candy floss usually in the higher branches of Pine Trees (See Fig. 2) and then during February or March they will be coming out of the trees and forming conspicuous snakelike lines as they traverse the ground searching for soft soil to burrow into. Processions of as many as three hundred caterpillars have been observed.

The body of this Caterpillar is covered with an incredible amount of microscopic, barbed hairs, some 60,000 of them, which are their defence mechanism. (See Fig.3) And here is the problem - each hair contains a chemical which causes a severe allergic reaction which can often be fatal for dogs. It is natural for a dog to be inquisitive and sniff or paw at these creatures and will be poisoned immediately. The pain will make the dog paw at its mouth and the result is gangrene mainly of the tongue and also of the mouth. If you should see your dog salivating, vomiting or just generally distressed, then immediate veterinary treatment is necessary if your dog is to be saved. I am not being overly dramatic – YOU MUST GO TO YOUR VET IMMEDIATELY. Do not brush a procession away as this can cause more problems, when they’re airborne than it solves, as spreading the hairs runs the risk of poisoning actually becoming higher as a result. I will never forget the day I was walking Lady and I saw her approach something in the track. As her head lowered, I screamed at her as loud as possible to leave it. All four paws left the ground in absolute shock that I had shouted at her, bless her, but it worked!! And yes, it was a single caterpillar that had obviously got lost, exactly the same as the one in the image.

There are many beautiful Pine Tree filled National Parks which you may think would be lovely to go to with your dog. Avoid these areas during February, March, April and sometimes May. Although these Processionary Caterpillars are prevalent in Pine Tree areas, as already stated, be aware that they will never be far away from any Pine Tree. They are just as likely to be found in urbanisations and road side plantings wherever Pine Trees are present.

Fig. 1

Fig. 2

Fig. 3