Oak processionary moth in Franconia: Red alert for allergy sufferers!

Oak processionary moth in Franconia: Red alert for allergy sufferers!

What is currently happening in many German forests is alarming. The oak processionary moth (Thaumetopoea processionea) is causing worrying reports in Bavaria. These voracious caterpillars, which are showing massive feeding behavior this season, especially in Franconia, not only threaten the oak forests, but also pose health risks. Mercury reports that the caterpillars' stinging hairs can cause skin rashes and allergic reactions. The damage to oak trees is currently particularly noticeable in southern Middle Franconia, as there have been signs of deforestation since mid-June 2025.

The larvae of the oak processionary moth eat almost exclusively oak leaves and show themselves through their characteristic web nests. In Gunzenhausen, where they have so far only appeared sporadically, two small forest areas have reported massive feeding. Regionally, many municipalities are complaining about an increase in damage reports compared to recent years. However, a positive light is suggested by the possible self-regulation by natural enemies such as parasitic wasps.

Health risks and allergy potential

But it's not just the oak trees that are at risk. The caterpillars' stinging hairs pose a high risk to human health. Contact can lead to described symptoms such as skin rashes, hives, blisters and severe itching. Uncovered areas such as the neck and arms are often particularly affected, and symptoms can range from hives to difficulty breathing. In severe cases, even anaphylactic shocks are possible, like this AOK explained. The danger of these caterpillars is not only limited to their active life phases: the stinging hairs remain poisonous for years and can trigger allergies years after the infestation.

To protect yourself, experts advise avoiding contact with oak trees with caterpillar nests. Children should be particularly warned not to stay in the undergrowth or near oak trees, as the caterpillars and their webs should not be touched. In case of contact, it is recommended to change clothes, shower and wash your hair immediately. BR emphasizes that inhaling the caterpillar hairs can cause respiratory irritation, which can be particularly problematic for people with previous exposure.

Prevention and control

Municipalities in the region are using various measures to combat the caterpillar population. In Rosenheim, for example, tea tree oil is used to prevent the caterpillars from shedding their skin. In other cities, caterpillar nests are actively removed from parks and street trees. Nevertheless, it refers Mercury point out that the burden of the oak processionary moth is increasing, but is not comparable to the dramatic conditions of 2019/2020.

Overall, the situation remains tense and it is important to remain vigilant. Oak owners and forest visitors in particular should be aware of the dangers and take appropriate precautions to protect the endemic health of people and nature.