Processionary caterpillars, despite their harmless appearance, pose serious problems for tree health and can also be dangerous to humans and pets. Identifying and effectively managing their nests is crucial to maintaining a healthy and secure environment. This guide offers you effective and ecological methods to control and eliminate these pests.
Identification of the processionary caterpillar nest
Before intervening, it is important to confirm the presence of processionary caterpillars. Nests generally appear as silky white masses clinging to the branches of pine, oak or cedar trees. They are particularly visible in late winter and early spring.
Mechanical methods of nest removal
Once the nest is located, several methods of mechanical removal can be employed. The use of a weeder (telescopic pole equipped with a branch cutter) allows you to cut infested branches. These operations should ideally be carried out in winter, when the caterpillars are still in the nest, to minimize the risk of contact with their stinging hairs.
Using pheromone traps
Pheromone traps are an eco-friendly method of attracting and capturing male butterflies before breeding. This reduces the future caterpillar population. These traps must be installed at the beginning of summer, when butterflies are flying.
The integration of natural predators
Encouraging the presence of natural predators is an ecological strategy to control the processionary caterpillar population. The cuckoo, bird species such as tits, or certain predatory insects such as calosomes are excellent natural regulators of these caterpillars.
Use of biological methods
The application of specific bacteria such as Bacillus thuringiensis (Bt) is another ecological approach. This biological treatment specifically attacks caterpillar larvae without impacting other insects. It is appropriate to apply it in early spring, when the caterpillars begin to actively feed.
Safety Precautions
When removing nests, it is essential to wear protective clothing to avoid contact with the caterpillars’ stinging hairs. Recommended equipment includes gloves, face mask and protective glasses.
By following these methods, you can effectively reduce and control the presence of processionary caterpillars in your environment, while adopting an approach that respects biodiversity and public health.
