Gardening

Treating the pine and oak processionary caterpillar


Confined to specific regions, processionary caterpillars are gaining ground.

In question, global warming and the choice of tree plantations on the edges of highways and in our municipalities.

What dangers do they represent and how can we protect ourselves from them? Information and practical advice.

  • Read also: Recognizing the processionary caterpillar

The processionary caterpillar: a stinging pest

  • The caterpillar has dorsal segments on which there are pockets called "mirror".
  • These pockets contain tiny orange hairs with hooks.
  • When the caterpillar feels threatened, its hairs break and disperse, releasing a stinging substance contained in small channels: thaumetopoéine.
  • This stinging defense is put in place from the third larval stage.

No need to be in direct contactwith this pest to undergo its terrible attack, because the wind takes care of dispersing its formidable very volatile hairs. Note that when they leave their nests, processionary caterpillars leave hundreds of stinging hairs that result from their various moults.

Risk for the health

  • Within 8 hours after contact with the skinrashviolent with severe itching. Sweat, scratching and rubbing accelerate the spread.

Treatment :remove clothes with gloves and wash them at high temperature. Dry them in a tumble dryer. Rinse off briskly with soap and water. Take an antihistamine and a cortisone-based cream (sold in pharmacies).

  • Within four hours after contact with eyes conjunctivitis and inflammatory reactions

Treatment : see an ophthalmologist urgently. The eyes will be rinsed after applying a local anesthetic. If some hairs are planted too deep, they will need to be surgically removed.

  • In case of inhalation:the respiratory tract may be irritated (sneezing, sore throat, difficulty in breathing, anaphylactic shock).

Treatment : consult his doctor

  • In case of ingestion: the mucous membranes of the mouth and intestines are inflamed (salivation, abdominal pain, angioedema).

Treatment : drink water to thin the hair and see your doctor. Endoscopy (visual exploration of the interior cavities) is sometimes necessary to remove all the hair.

Warning ! reactions worsen with each new contact.

A danger to our pets

If you have a pine, a tree or a Oak in your garden or in the area where you walk your animal, be vigilant, because it can come face to face with a procession of caterpillars. Curious, your dog or cat will try to play with them or worse to eat them and there it is!

  • In case of contact, your animal, especially the dog, may develop the reactions mentioned above and in particular anaphylactic shock. To try to relieve himself, he will lick himself which will lead to necrosis of the tongue.If it is too large, his tongue may fall out or be amputated. In some cases, the animal will no longer be able to feed and will have to be euthanized.
  • If in doubt, take your animal to the vet. It is a life-threatening emergency.

Treatment : anti-inflammatory, antihistamine, antibiotic, heparin or amputation in the most severe cases.

Treatment of processionary caterpillar

There are no mandatory regulations to eradicate the pest. However, faced with the magnitude and danger of processionary caterpillars, some municipalities are applying bylaws to force tree owners to remove nests and implement preventive and annual treatments.

Definitive solutions:

  • Cut down colonized trees.
  • Avoid planting pines, oaks and cedars in populated areas.

Chemical solutions:

  • By spraying trees with a treatment based on Bacillus thuringiensis in autumn. While feeding, the caterpillar will ingest the poisonous fungus and die. This process respects other animals and people.
  • With an insecticide, diflubenzuron. By ingesting it, the larvae stop developing (practiced in winter).

Ecological solutions:

  • Manually. After spotting the nests, they are cut with a telescopic pole equipped with shears, and then burned.
  • With a vacuum cleaner fitted with suitable filters. The nests are cremated.
  • With a synthetic pheromone trap. Female pheromones are placed in a container coated with glue. The attracted males will come and fly above. Exhausted, they will eventually die trapped on the walls of the container. This system can be installed without danger and limits reproduction (to be set up in early summer).
  • With an eco-trap. It involves putting a completely airtight collar around the trunk of the infected tree. This is connected to a tube that goes down into a plastic bag filled with soil. It is only effective on pine processionary caterpillars, as they will be trapped when they leave the tree to bury themselves. It is a safe and formidable device.
  • By installing tit nests. These birds feast on caterpillars and do not develop any allergies. They can eat about forty a day.

Biological solution:

  • Plant birch trees. Their essence is a repellent for processionary caterpillars.

Warning ! some of these measurements must be carried out by professionals.

Advice on processionary caterpillars

  • INRA developed the application ACT (downloadable from play store…). It allows everyone to identify the invasive insects observed in their region and to declare them. This participatory process makes it possible to alert populations at risk.

Predators of the caterpillars: the tit, the cuckoo, the hoopoe, certain species of bats.

  • Read also: Recognizing the processionary caterpillar

ATmeditate : "The most beautiful butterfly is just a dressed caterpillar" French proverb

L.D.

© alco81

Video: THE OAK MOTHS STOP HERE! (October 2020).