Processionary moths are known for wrapping oak trees in webs. Their caterpillars romp around in large numbers in the branches, are poisonous and therefore feared. These moths are rarely mentioned in connection with birch trees. Is this an all-clear for the birch?
Does the processionary moth attack the birch tree?
Birches are not endangered tree species. However, in years with a very high infestation it can happen thatoccasionally young birch treesare attacked by processionary moths. The necessarycontrolrequires special knowledge in dealing with insecticides and should beleft to professionals.
Which regions are particularly affected?
The processionary moth occurs increasinglyin warm and dry regions of Germany, for example in the Rhineland, and is the largest pest of oak trees.
What do the processionary moth and its caterpillars look like?
The adult butterfly is inconspicuous gray-brown and has a wing width of 3-4 cm. The caterpillars are up to5 cm long, yellowish-browncolored and covered with countless longwhite hairs. What is striking is that they usually occur in masses and can practically infest the entire oak or birch tree. Furthermore, the birch tree is visited by more than 100 species of butterflies every year. Caterpillars on birch trees are not uncommon, but are usually harmless.
When are processionary moth caterpillars active?
The larvae hatch aroundmid-Augustand are active in the treeuntil October. They then form silky nests in which they spend the winter. In spring they move towards the ground, where they burrow into the earth and cocoon themselves.
How can processionary moths be dangerous to people?
Thestinging hairsof the caterpillars contain a protein called thaumetopoein. It can be considered asNettlePoison. Contact with the hairs can have serious consequences for people, e.g. E.g.:
- Skin irritation like itchy caterpillar dermatitis
- Bronchitis
- Conjunctivitis
- allergic shock reaction
The hairs can break off very easily, float around in the air and be absorbed through the respiratory tract as you walk past. The stinging hairs are found on shed skins lying around somewhere in the undergrowth.
How can I protect myself from processionary moth caterpillars?
Corresponding warning signs or barriers are often set up in affected forests. In general, you shoulddon't get too close to an infested tree, especially don't touch the caterpillars. And if you do come into contact with them unexpectedly,showerand change your clothes. See adoctorimmediately if you experience the first symptoms of an allergy.
Tip
Report infected trees to the local garden office
There is no obligation to report oak processionary moth infestations. If you spot an oak, birch or other tree with countless caterpillars while out on a walk and suspect the oak processionary moth, you should still report it to the authorities. They can then decide whether control is necessary.