The life cycle of the processionary moth
Between July and September, adult moths emerge from the ground, living for only a day or two they fly to the tops of pine trees, where they lay their eggs. Later, when the eggs hatch, the caterpillars begin feeding on pine needles doing a lot of damage to the host tree. As temperatures drop, they gather together to build the characteristic white cotton candy like nests, which help them survive the winter cold. At the end of larval development they descend from the trees, one after the other in procession (hence their name) to burrow into the ground to pupate.
You can recognise them by their distinctive orange and brown colour and blue bands. It is the bristly hairs that are dangerous as they contain a powerful toxin and cause severe rashes and respiratory problems.
If the caterpillar is stressed or threatened it can eject its hairs, which act like harpoons that penetrate and irritate any exposed skin. Dogs are particularly vulnerable as they will pick up the hairs on their paws and lick them as they start to itch.This transfers the hairs onto the animal’s tongue, resulting in itching, swelling, vomiting and even death.
What to do if you come into contact with the processionary caterpillar?
Seek medical assistance – head to the local emergency centre (PAC) – the likely treatment will include strong anti-histamines and a topical steroid cream
What to do if your pet comes into contact with the processionary caterpillar?
If your pet comes into contact with the processionary caterpillar, small white spots will appear around their mouth and on the tongue. As the rash develops, the animal will become distressed and possibly drool. If untreated, animals can die as the tongue will swell. If you think your pet has been affected then you should visit a vet immediately. They’ll likely administer a cortisone injection to counteract the reaction.How to fight back?
There are various ways to fight back against the pine processionary moth and it’s poisonous caterpillars.
- Infected trees can be treated by insecticide injection in the autumn
- The use of pheromone traps strapped to the tree in question
- Direct injection of insecticide into the individual nests
- Installing physical barrier traps around the base of treesThe use of a bacterium powder
- Physical removal of nests (carries danger)
In the past a shotgun was often used firing salt cartridges into the nests, thus breaking them down and exposing the caterpillars to the cold and hopefully death!
Today it is possible to buy air-gun pellets tipped with a dose of insecticide to fire into nests.
Another old method of destruction was to gather the nests and burn them – this is a really bad idea, as it can cause a shower of the poisonous hairs to rain down on those below!
Natural Predators
Despite the toxic nature of the caterpillars there are some natural predators, including the delightful Hoopoe bird with it’s distinctive plumage and crest. In addition great tits, blue tits and coal tits feed on the young caterpillars and pupae as do blackbirds and some thrushes.
At night bats and nightjars feed directly on the moths and doormice dig up and eat the grubs.
What you should do if you find them?
If you find the processionary caterpillar within your community:
You should immediately inform fellow homeowners and organise their removal. In some areas, the council will have a removal service, but where this isn’t the case, you should contact a specialist. Remember, you should never attempt to remove the caterpillars yourself as they pose a serious health risk.
You should also be careful of any nests the caterpillars have left in the trees. These will also contain hairs that the larvae have left behind. You shouldn’t try to cut down the nests or burn them yourself, because the hairs can become airborne.
Furthermore, if there’s someone new to your community, alert them as to the risk – especially if they’re a dog owner.
Read more about the remarkable Hoopoe bird here https://totnmallorca.com/the-wild-north-the-hoopoe/
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