The fight against the pine processionary

When summer comes to an end, a new cycle of the pine processionary begins. In the months of September and October, from the eggs laid by the butterflies in the treetops in the summer months, the caterpillars of the processionary hatch.

After hatching, the caterpillars will pass through five larval stages. Between the first and second larval stage, the caterpillar colonies jointly build small silk bags with a collective shelter function. They spend the daytime in these bags and come out to feed in the evening. At this stage the caterpillars are hardly seen.

This is where our biological treatment will be applied. Biological control consists of spraying with nematodes and must be applied to the larval stages in the early stages of development (September-October) before the stinging hairs of the third stage develop.

Fumigation with our nematode formula effectively eliminates the caterpillars and breaks the life cycle. It is important not to let the larvae enter the next stage of their development.

Another option to fight the processionary disease is through our innovative Endotherapy treatment, which consists of injecting the insecticide directly into the trunk of the pine trees and guaranteeing its total absorption in less than 3 hours. One treatment guarantees processionary-free pines for a year.

When the larvae enter the third larval stage the caterpillars develop stinging hairs that produce rashes and allergies in people and animals. Especially for our pets the caterpillars are extremely dangerous to the point that it is fatal for dogs and cats, which can even die from suffocation.

In the autumn months the larvae build much denser and more conspicuous pockets on the trees, in which they will spend the winter.

With the arrival of spring, the caterpillars descend from the tree in long rows in order to bury themselves and remain in pupa form until the summer months. Hence their common name, the “processionary”. It is at this time that we are most aware of their existence and realize the problem they pose. At this time our collar traps are effective, which are placed on the trunk of the tree and collect the caterpillars when they come down to the ground.

Following their life cycle, the caterpillars are finally buried, where they pass to the pupa or chrysalis stage.

In summer, depending on the temperature and humidity, the chrysalis hatches and butterflies emerge whose life span is very short (between one and two days). These will mate and fly to the pine trees to lay their eggs and repeat the cycle.

In this last phase of the cycle our pheromone traps are effective.

Vegetation affected by the processionary process includes the following species; Salgareño pine (Pinus nigra), Canary Island pine (Pinus canariensis), Scots pine (Pinus sylvestris), Maritime pine (Pinus pinaster), Aleppo pine (Pinus halepensis) and Stone pine (Pinus pinea).

Our best allies in biological pest control are the natural predators of the pine processionary.

The processionary pine in all its stages of development serves as food for other animals. Among its natural enemies are insects such as ants, different species of the order Hymenoptera and cicadids, the latter eating the eggs.

Also mammals such as the common dormouse (Eliomys quercinus) and the bat (Pipistrellus pipistrellus), which hunts the butterflies in the summer months, are excellent allies in the fight against the plague.

Among the insectivorous birds we can find a great variety of species specialized in the hunting of the processionary.

The Coal Tit is the one that catches the caterpillars while eating among the leaves of the pines and even opens the nest bags where it devours the smaller caterpillars. The Blue Tit (Cyanistes caeruleus) and the Cuckoo (Cuculus canorus) are also predators of the processionary.

Other larger birds are the Cuckoo (Clamator glandarius), the Blackbird (Turdus merula) and the Hoopoe (Upupa epops) a bird with a characteristic crest that hits the caterpillar with its long, thin beak with the intention of shedding the annoying stinging hairs.

We recommend the installation of a nest, picnic area and water dish in the garden to attract these birds. It is also possible to install bat nests or an insect hotel.

Apart from our biological treatment, which eliminates the caterpillars before they become dangerous and thus prevents them from causing us harm, you can find several alternatives in our online shop to combat the pest. Setting up an insect hotel or bat’s nest contributes to the control of the pest in a natural way.

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