Searches

Processionary of the pine


There pine processionary it must be destroyed in the winter months. In fact, it is during this period that the insect takes shelter in the nest it has built, a large whitish cocoon easily visible even from a distance, becoming more vulnerable.

There pine processionary, Thaumatopoea pityocampa, is a moth that attacks all coniferous trees (especially pines and cedars) causing irreparable damage and in the worst cases the death of the plant. If you happen to meet her, immediately run for cover (in this article we will tell you how) but also report it to the Municipality, the forestry authority or the agricultural consortium in the area. Since 1998, a Ministerial Decree has made it compulsory to fight this insect because its danger is high, and not only for plants.

The nest of the pine processionary it is typically found among the branches of conifers (but it can also affect chestnut, beech, hornbeam, birch and hazelnut trees) usually at the tip, and is populated in large numbers by the larvae that build it: hairy caterpillars 3-4 cm long of the brown ones reddish. In case you decide to open a nest out of curiosity, which I personally did and I strongly advise against it, be careful because the caterpillars are covered with stinging hairs that can cause serious problems.

There processionary it is dangerous for humans when it comes into contact with the skin, in this case it gives rise to annoying dermatitis, but much more in case of inhalation because the stinging hairs irritate the respiratory tract. In case of contact, you must immediately wash your hands with warm water and soap (ammonia is useless) but the itching remains for a few days and the blisters for a couple of weeks.

In case of inhalation, at the first symptoms (sneezing, coughing ..) it is better to go to the doctor or to the emergency room. Ditto in case of eye redness: if a hair of processionary it sticks in the cornea it may be necessary to remove it surgically but it can also result in a serious infection to the point of causing blindness. The risk is also high for animals, especially dogs and horses.

We said at the beginning that the pine processionary it must be eliminated in winter and it is so. The safest way to get rid of it is to cut cleanly the branch on which the nest is located by sawing it about thirty centimeters below the lower part of the cocoon (what is needed to get rid of all possible offshoots). Then, acting with caution, it is destroyed with fire.

Fire is the only safe way to suppress the caterpillars of the Thaumatopoea which, gathered in the nest, have a surprising vitality. If you happen to do this, you will find that it takes a few minutes of open flame to open the cocoon and even more before you see the larvae stop moving.

No insecticide replaces the action of fire in eradicating the pine processionary. The problem is that the nests are often found at a great height and it is not easy to reach them. In my case I had to deal with five nests at the same time, two on an almost secular Thuja at a height of 15 meters, and three that had found a home on a young silver fir.

I intervened on the fir tree as I told you in January (I waited until there was some snow on the ground to make the bonfire) but on the Thuja I did nothing and I hoped for the strength of the tree (usually the processionary attacks young specimens because he knows he has an easy life).

I must say that it went well for me: in spring the nest emptied and caterpillars must have set out in single file on the trunk (it is from this proceeding as in a procession that the name derives processionary), but the winter after I never saw anything again. I was also okay with not hurting myself because I was unconscious. Caterpillars are stinging even after being burned!

The larvae of processionary to feed (from maro onwards when they leave the nests) they completely defoliate the trees and dry them (in this they resemble the defoliator caterpillar of the boxwood). In my case, it helped me that an infestation had been going on in the area for some time and the regional forest service was already carrying out specific campaigns to combat insecticide substances (such as diflubenzoron) and biological and biotechnological control.

In the case of the pine processionary it is necessary that insecticides are used only by specialized and authorized personnel as part of coordinated control actions. Also because they should be used on caterpillars in spring and not on nests, whose structure is resistant to chemicals.

The biological fight against pine processionary is based on the use of bacillus thuringiensis of the kustaki variety, but it is not easy to practice. However, this type of insecticide can be purchased on Amazon.

The biotechnological fight, on the other hand, involves the use of pheromone traps to be placed between June and July in the period of flickering. Pheromone traps are also available on Amazon. One of the few natural enemies of Thaumatopoea pityocampa is the rufa ant, which has given interesting results in some experiments. The mechanical struggle, removal and fire of the nests, remains basic.

You may also be interested in our article:Processionary: the risks for dogs and humans


Video: Caravan of pine processionary caterpillars (November 2021).