Chestnut trees in August: Brown color by Miniermotte explained

Chestnut trees in August: Brown color by Miniermotte explained

Currently, many chestnut trees in Baden-Württemberg are affected: their leaves show a striking brown color, which is primarily caused by the infestation of the minier moth. What does that mean for the trees and their surroundings?

Causes of the brown color

The brown coloring of the leaves that occur in high summer time is a clear signal for the infestation from the larvae of the minier moth. According to Olaf Zimmermann, an insect customer from Karlsruhe, this effect is particularly pronounced this year. The minier moth originally comes from Southeast Europe and has apparently adapted to the increasing temperatures of recent years. These climatic conditions seem to help the insects, since their natural enemies, such as special sidelines, are not sufficiently represented in the region.

Effects on the trees

One consolation: The trees themselves are not in acute danger due to the infestation. Zimmermann emphasizes that no chestnut has died due to the larvae to this day. The infestation mainly has optical effects, but can weaken the resilience of the trees and make them more susceptible to other diseases, according to the BUND Baden-Württemberg.

Tips for fighting and prevention

In order to curb the spread of the minier moth, experts recommend collecting the fallen leaves in autumn. The larvae, which could otherwise form the next generation of pests, hide in it. In addition, recording damage to databases can be an important basis for future control measures.

Municipal planning and biodiversity

Interestingly, only the white-flowering horse chestnut is affected by the minier moths. Experts therefore advise municipalities to use red -flowering chestnut types and their hybrids when planning new plantings in order to reduce the risk of infestation.

Potential and future prospects

While the chestnut mintment moth is considered relatively "presentable" from the perspective of crop protection, the newly occurred Japanese beer is a more important threat. This beetle was first demonstrated in Germany in 2021 and could have serious effects on the domestic flora.

Overall, the problem around the minier moth shows a larger picture: it is not only an indication of the change in the environmental conditions, but also a memorial for the need to promote biodiversity in urban and rural areas. In view of the challenge of protecting the health of the trees, extensive strategies are required to secure the future resilience of our forests.