My garden is full of processionary caterpillars, what can I do?

Dangers of processionary caterpillars Mallorca

If you take a stroll through any large park in Mallorca or the countryside these days, you will notice the processionary caterpillar wandering along the paths, which for yet another year is proliferating earlier due to the drought and the heat. Trees are filled with nests and in gardens and parks you can see rows (processions) of caterpillars that have climbed down —or fallen— from the tree tops and are crawling around looking for a place to bury themselves and thus complete their life cycle.

This happens in pine trees that have not been treated preventively during the months of September, October and November, and Doctor Pino is frequently consulted by people who do not know how to deal with the problem, which is very harmful for people and can be lethal for their pets. Although there are various options to minimise the danger caused by this pest, they must all be considered palliative, and none of them offer a completely efficient solution to the problem, as does the endotherapy treatment we carry out on the pines of Majorca from the end of September to the beginning of December each year.

So what can we do?

No technique can effectively prevent the risks caused by the presence of the processionary caterpillar in your garden, although a number of measures can be taken to help minimise the extent of these risks:

Doctor Pino Mallorca processionary nest removal

1.- Manual removal of nests from trees.

Using an extendable pole with a scissor at the end, nests that are within the operator’s reach can be cut.

Pros: Timely removal of nests can significantly minimize the number of processionary caterpillars in the area.

Cons: It is an expensive and time-consuming process, as we will often have to climb into the tree canopy to access as many nests as possible. We cannot guarantee the removal of 100% of the nests, as many of them are beyond the sight and reach of our operators.

2.- Ring-trap in the trunk of the pine tree.

Placement of a physical barrier of plastic and foam around the perimeter of the trunk that forces caterpillars crawling towards the ground to pass through predetermined holes with plastic bags at the ends that trap the caterpillars and prevent them from returning to the top of the tree.

Pros: The ring trap can minimise the number of processionary caterpillars in the area by trapping those caterpillars that crawl from the canopy to the ground along the tree trunk. Lower cost than the nest removal process.

Cons: A good number of caterpillars fall directly from the nests (located at the tip of the branches) to the ground on days with moderate to strong wind, thus avoiding their capture with this trap placed on the tree trunk.

Doctor Pino trampa anillo tronco procesionaria Mallorca

What other measures can we take?

If you have dogs in a garden infested with processionary caterpillars, the ideal thing to do is to keep them inside the house or on a leash in a clean area (a terrace, for example), keeping a constant watch to ensure that the caterpillars do not enter the area. Remember that dogs are curious animals and can approach to sniff the caterpillars with consequences that can be very serious.

Pay special attention to children during this period. The processionary caterpillar can cause dermatitis, eye lesions, hives and allergic reactions which could be exacerbated by direct contact with the insect, leading to intoxication in the form of rashes that can cause conjunctivitis and more serious respiratory problems.

If you see a line of processionnaires in your garden, spray them with insecticide and, once they are dead, put them in a closed bag and throw them in the rubbish bin. Try not to step on the caterpillars with your foot. The hairs are equally stinging after the caterpillar is dead.

Remember that the only method that guarantees the protection of your pine trees and a processionary caterpillar-free garden is endotherapy or injection into the tree trunk. Contact Doctor Pino and avoid the problems caused by the presence of this pest next year.