In addition to the damage they can cause to trees, these caterpillars pose a real danger to human and animal health due to their hairs, which can cause severe allergic reactions.

These caterpillars have a complex life cycle, as El País explains. During the summer, adult moths lay eggs on pine needles.

The larvae emerge between September and October and spend the winter in silk nests in tree branches. As temperatures rise, they begin to descend in single file to the ground, where they bury themselves and pass into the chrysalis stage, giving rise to future moths.

Although caterpillars can defoliate pine trees, they rarely kill them because they do not consume new growth, allowing the trees to regenerate in the spring.

Risks to humans and animals

The main dangers of the pine caterpillar come from its hairs, which are released as a defense mechanism and can cause serious allergic reactions. The most common symptoms include:

  • Skin reaction: skin irritation with itching, burning, redness and swelling;
  • Respiratory problems: inhaling hairs can cause coughing, breathing difficulties and, in extreme cases, anaphylactic shock;
  • Eye irritation: symptoms similar to conjunctivitis, such as red, itchy and swollen eyes.

In animals, especially dogs, contact with caterpillars can be extremely dangerous, leading to tongue necrosis and other serious complications.

If you are exposed to hairs, follow these steps:

  • Avoid rubbing the affected area to prevent the hairs from spreading;
  • Wash your skin and eyes with plenty of water;
  • Use tape to remove loose hairs from the skin;
  • Apply a moisturising cream to relieve irritation;
  • Take an oral antihistamine to reduce the allergic reaction;
  • Consult an ophthalmologist if there is eye contact;
  • Go to the emergency room in case of a severe reaction.

For animals, seek immediate veterinary care if you suspect contact with caterpillars.

Preventive measures

  • Avoid areas with pine trees during the winter months and early spring;
  • Keep pets on a leash in risky areas;
  • Signal and inform the authorities if you find nests or large concentrations of caterpillars;
  • If nests need to be removed, contact municipal services or specialists, as improper removal can spread the stinging hairs.

The pine processionary caterpillar is a natural phenomenon, but requires precautions to avoid incidents. Staying informed and following good prevention practices is essential to minimise risks and protect both the population and pets.