Oak processionary caterpillars are a serious threat to both human health and nature. Immediate action is essential if you discover them in your garden. Here’s how to identify and eradicate these harmful pests effectively.

Recognizing Processionary Caterpillars

Oak processionary caterpillars are easy to spot due to their distinct features:

  • Appearance: These caterpillars are covered in visible hairs and can range in color from yellow-brown to grey-blue or black as they mature. They grow to about 5 cm in length.
  • Nests: They create large, spider web-like nests that can extend over considerable distances, often hanging from the trunks of infested trees. These nests can create a ghostly appearance, especially at night.
  • Life Cycle: After the caterpillar stage, they transform into chrysalises, with moths emerging in August. Though the adult moths are not dangerous, the stinging hairs from the caterpillar phase can remain airborne, necessitating caution.

Dangers of Processionary Caterpillars

  • Damage to Trees: These caterpillars primarily attack oak trees and occasionally beeches. Infestations can severely weaken trees, making them susceptible to other pests and potentially leading to the death of entire forests.
  • Human Health Risks: The caterpillar hairs are harmful to humans. They can cause allergic reactions and respiratory issues such as breathing difficulties, asthma, and bronchitis. Contact with the hairs can also lead to skin and eye irritations, fever, dizziness, and in severe cases, anaphylactic shock. The hairs can travel through the air, making avoidance difficult.

What to Do in Case of Infestation

  1. Avoid Infested Areas
  • Keep Distance: If you find processionary caterpillars, avoid the infested areas. Mark the affected zones clearly to prevent others, especially children, from coming into contact with them.
  1. Do Not Attempt DIY Removal
  • Professional Help Needed: Do not attempt to remove the caterpillars yourself due to the risk of exposure to their harmful hairs. Report the infestation to the competent authorities who can assess and address the situation.
  1. Professional Removal
  • Special Equipment: Authorities may employ professionals equipped with specialized gear to either vacuum or burn the caterpillars. Burning is particularly effective as it destroys the dangerous hairs completely.
  • Handling Harvests: If you have fruit or vegetables in an infested area, wear gloves during harvest and wash produce thoroughly before consumption. For safety, it might be best to avoid consuming them.

By following these steps and precautions, you can effectively manage and eradicate oak processionary caterpillars, protecting both your garden and your health from their harmful effects.

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