Processionary caterpillars are pests that cause significant damage to vegetation and can cause allergic reactions in humans but more often harm our animals. To preserve your garden or green spaces, it is essential to find natural methods to get rid of these insects without harming the environment. In this article, we offer several ecological alternatives to fight processionary caterpillars.
Favor natural predators of processionary caterpillars
Rather than using chemical pesticides, it is preferable to favor the processionary caterpillars’ natural predators in order to regulate their population. Among the main enemies of caterpillars are insectivorous birds, such as tits, swallows, sparrows and cuckoos.
Install nesting boxes to attract tits
Chickadees are particularly fond of processionary caterpillars and can consume up to several hundred a day. Installing nesting boxes in your garden will attract these birds and thus reduce the number of caterpillars present.
- Choose a location sheltered from wind and weather, at a height of about 2 to 4 meters from the ground.
- Make sure the birdhouse’s flight hole is facing north or east to avoid high heat and direct sunlight.
- Favor natural materials such as raw wood, to promote the integration of the nest box into its environment and provide a comfortable shelter for the birds.
Plant trees suitable for the nesting of insectivorous birds
The choice of tree species in your garden can also play an important role in the fight against processionary caterpillars. Insectivorous birds need a variety of food resources and a suitable habitat for nesting and breeding.
Birch trees, for example, are particularly popular with tits because they host a wide variety of insects and offer many nesting opportunities.. Also consider planting berry shrubs, such as black elderberry or blood dogwood, which will provide a supplemental food source for birds during migration.
Use mechanical methods to eliminate processionary caterpillars
In addition to natural predators, it is possible to implement mechanical methods to reduce the population of processionary caterpillars. These techniques mainly consist of destroying the caterpillars’ nests and preventing their progression in the trees.
Remove caterpillar nests by hand
To eliminate processionary caterpillars, it is possible to manually remove their nests when they are still young and few in number. Wear gloves and protective clothing to avoid contact with the stinging hairs of the caterpillars, and place the nests in an airtight bag before destroying them by burning them.
Set up processionary caterpillar traps
Specific traps can be installed around tree trunks infested by processionary caterpillars. These devices consist of a strip of fabric impregnated with glue, which traps the caterpillars as they attempt to move along the tree. Once the caterpillars are captured, they should be removed and safely destroyed.
Natural treatments against processionary caterpillars
Finally, there are also natural treatments that can effectively fight processionary caterpillars without resorting to chemicals that are harmful to the environment and human health.
The use of entomopathogenic nematodes
Entomopathogenic nematodes are microscopic worms that parasitize insect pests, such as processionary caterpillars. They enter their body and release a bacterium that causes their rapid death. Nematodes are available as a powder to be diluted in water and can be sprayed on infested areas.
Bacillus thuringiensis, a natural bacterium
Bacillus thuringiensis is a bacterium naturally present in the soil and which produces specific toxins for certain harmful insects, including processionary caterpillars. This bacterium can be used in the form of a spray or granules, to be applied to the leaves of infested trees.
By adopting these different ecological methods and acting preventively, you will help protect your environment while effectively fighting processionary caterpillars.