The Oak Processionary

The Oak Processionary

In the Hambach forest, as in many forests in central Europe, nests of the oak processionary have been found. On the 3rd and 4th of June of this year,
the city of cologne had to discuss this matter. For the last four to five years it has been known that this type of caterpillar is in the area around cologne.

The oak processionary is a moth that lays its eggs in the early autumn. It prefers the tree tops for laying eggs. The caterpillars hatch between
the beginning of April and the beginning of May. They have 6 instars, or phases between which they pupate multiple times. Beginning with the third instar they become covered in toxic bristles. The last pupation happens around the end of June. The oak processionary is commonly found on oaks, in the beginning mostly in the tree tops but during later phases also moves further down the tree. They eat mostly during the night and move around in up to 10 meter long processions which consist of a couple dozen caterpillar. The processions move from branch to branch or to a neighboring tree. During the day, they are mostly found in their nests. The moth has a couple of natural predators but the caterpillar has few due to the toxic bristles. If a human comes into contact with these bristle, there is a health risk as pseudo allergic reactions on the skin or or the respiratory system can occur. Sometimes even dizziness. Fever and tiredness. There is no medication or antidote to the toxin in the bristles but we have had good experience with anti-itch creams.

A survey has been done, mostly in and around the tree house villages. Red and white tape marks affected oaks. If a tree is affected is easily
observed, as the nest (white, shimmery webs) are easy to spot. The effort of removing nest with all means available for us has begun.

We are still happy about visitors and newcomers but we’d like to inform you about the situation, so everyone can form an informed opinion and gauge the risks.

Tips for handling the oak processionary might include:
* DO NOT TOUCH! (nest, webs, caterpillars, cocoon)
* do not burn, stir up or poke (bristles everywhere)
* don’t walk barefoot (or if done, be cautious during the night -> processions
* be careful with skin contact with oaks
* don’t leave textiles in the open -> put in plastic bags (during procession though a tree house they leave bristles on textiles)
* be extremely cautious with infants and animals (like dogs)
* search oaks before climbing up
* after heavy rain, search the tree house for signs of the caterpillars (they seek shelter)
* if a nest is found, speak to people in the forest, who have experience with handling and removing nests
* upon experiencing pain, one can go to a doctor (contact details on request)

With this problem, as it is always the case, external help is welcome and helpful.  As it is the goal to clear all tree house villages of nests and
caterpillars, we need specialized equipment and if any skin contact has happen, we need medication.

Therefore, we are happy about getting the following items
* ABC suits, gloves etc
* Tape
* sealable plastic bins
* vegetable oil
* Fenistil, Cortisone, Calendula cream, herbal remedies against itching

If you know people (i.e. from tree care services) who have experience in removing nests and who want to help us, call us or write an email. (hambacherforst{at} or 0049 (0)178 163 7325

This Post Has One Comment

  1. Biodiversity PR HQ

    Do not panic, every year several people die from the alelgetic shock to bee, wasp and hornet bites while there has been no deaths or severe hospitalization due to this invasive visitor. Bring cortisone cream just in case and remember that their cateppilar stage is only for 1 to 2 additional month so they will not be in the forest for the mass actions or the cutting season.

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