Oak processionary caterpillars are dangerous for both humans and nature. If you discover them in your garden, immediate action is required to prevent harm. These caterpillars are unwelcome guests in our gardens, and while some insects, like ladybugs, are beneficial, oak processionary caterpillars are not. Here’s what you need to know to eradicate them effectively.
Recognizing Oak Processionary Caterpillars
Oak processionary caterpillars are easily identified by their visible hairs, which cover their entire bodies. Initially yellow-brown, their color changes to grey-blue or black as they mature. These 5 cm long caterpillars create large nests resembling spider webs, which can spread over long distances. These webs typically hang from the trunks of infested trees, creating a ghostly atmosphere at dusk. After the caterpillar phase, they transition into chrysalises, and by August, moths emerge, though they are no longer dangerous. However, their stinging hairs can still pose a threat by floating in the air.
Dangers of Oak Processionary Caterpillars
These caterpillars predominantly target oaks but can also infest beeches, making them a serious concern in forests and gardens. The damage they cause to trees can be severe, often weakening the trees to the point where other pests can easily take over. In some cases, entire forests can die off and fail to regenerate, causing significant ecological damage.
Health Risks to Humans
It is not just trees that are at risk—humans are also in danger from these caterpillars. The stinging hairs they shed contain a toxin called thumetopoein, which can lead to allergic reactions, breathing difficulties, and even severe conditions like asthma, bronchitis, and anaphylactic shock. The hairs are dispersed by the wind, making it difficult to avoid exposure. Skin contact can cause skin irritations, fever, dizziness, and eye irritations. Therefore, even if you avoid the infested area, the airborne hairs remain a risk.
What to Do in Case of Infestation
If you find oak processionary caterpillars in your garden, the first step is to avoid the affected areas, especially to protect children. Mark off the area clearly and do not attempt to remove the caterpillars yourself. Handling them requires special protective equipment to prevent exposure to the dangerous hairs. It’s essential to report the infestation to the appropriate authorities, who can map the area and arrange for professional help. Experts equipped with the right tools can vacuum up or burn the caterpillars, eliminating the danger permanently. The burning method is particularly effective as it destroys the hairs along with the caterpillars.
Additional Precautions
If you have fruit or vegetables in an infested area, use gloves when harvesting and wash the produce thoroughly before consumption. For extra safety, it is advised not to consume anything from the infested garden until it has been treated.
By following these steps, you can eradicate oak processionary caterpillars and prevent the harmful effects they cause to both the environment and human health.
