Biological control of the pine processionary moth

What is the pine processionary moth?

The pine processionary moth is a moth whose larvae feed on pine needles. It is especially common in Southern Europe and the Iberian Peninsula.

 

 

During winter, the caterpillars live in characteristic white silk nests that can be observed in the crowns of pine trees. Towards the end of winter or beginning of spring, they leave the tree, forming the well-known processions to bury themselves in the ground and complete their cycle. This behavior is what gives the species its name.

 

 

 

What damage it causes

 

The caterpillars feed on pine needles, which can lead to:

• tree weakening
• foliage loss
• reduced growth
• increased vulnerability to other pests

 

Furthermore, the urticating hairs of the caterpillars can cause:

• skin irritations
• allergic reactions
• respiratory problems
• severe injuries to dogs or other animals

 

For this reason, the presence of the pine processionary moth is of particular concern in inhabited areas, parks, and recreational areas.

 

 

Traditional control methods

 

For years, the control of the pine processionary moth has primarily relied on:

• chemical treatments
• pheromone traps
• manual removal of nests

Although some of these techniques can reduce caterpillar populations, they also have drawbacks.

Chemical treatments, for example, can affect other beneficial insect species and disrupt the ecosystem's balance.

Therefore, there is an increasing shift towards biological control strategies.

 

 

Biological control: letting nature do the work

Biological control involves promoting the presence of natural predators that regulate pest populations naturally.

In the case of the pine processionary moth, several species of insectivorous birds feed on its caterpillars, especially when they are small.

Among the most important are:

• the Great Tit (Parus major)
• the Eurasian Blue Tit (Cyanistes caeruleus)

These birds consume large quantities of insects during the breeding season to feed their chicks.

A single tit nest can catch thousands of insects during the breeding season, thus contributing to the natural control of various forest pests.

 

 

How to encourage insectivorous birds

 

One of the most effective measures to increase the presence of these birds is the installation of nest boxes.

In many pine forests and agricultural areas, there is a scarcity of natural cavities where these species can nest.

Nest boxes help compensate for this lack of shelters and allow insectivorous bird populations to increase.

For them to be effective, it is important that the nest boxes:

• are made of natural wood
• have the appropriate entrance size
• are placed at a safe height
• are kept clean each season

When several nest boxes are installed in a pine forest area, birds can become a natural ally in insect regulation.

 

 

A more sustainable approach for our forests

 

Promoting biodiversity is one of the most effective strategies for maintaining healthy ecosystems.

Biological control does not aim to completely eliminate a species, but rather to keep its populations in balance with the environment.

Promoting the presence of insectivorous birds, bats, and other natural predators helps reduce the need for chemical treatments and contributes to preserving the natural richness of our landscapes.

Initiatives such as the installation of nest boxes, increasingly used in conservation projects and sustainable agriculture, demonstrate that working with nature is often the best long-term solution.