Although the robinia tree is very robust, it can still happen that it is troubled by some pests. If you intervene in time, you can prevent worse things.
The robinia, also called Robinia pseudoacacia, is one of the robust trees. Life-threatening diseases or a life-threatening infestation of pests hardly occur in healthy robinia.
Often, however, the owner of the trees is troubled by robinia leafminers, aphids or the Phloespora leaf spot disease. Here's how to get these robinia problems under control.
Overview of common diseases and pests:
✢ Robinia leaf miner
As the name suggests, the robinia leafminer is a pest that specializes in the leaves of the robinia for food. The leaf miner has only been found in Europe since 1983 and has no natural predators with us.
An infestation is easily recognizable by the characteristic damage pattern of a meandering feeding track in the leaves.
The caterpillars can easily be collected from the infected leaves. However, the measure is not really necessary, because despite the optical damage, the health of the robinia is not adversely affected by the leaf miners.
L Phloespora leaf spot disease
The phloespora leaf spot disease is a relatively common disease of the robinia, which is caused by the fungus Phloeospora robiniae and occurs especially after a rainy spring.
The damage pattern shows up in brown spots on the leaves, which reach a diameter between half and one centimeter. In the course of the year the leaves often appear deformed and are torn at the edges. Phloespora leaf spot disease can also affect shoots or petioles.
The infestation is not immediately life-threatening, but should be combated. First try the manual solution to the problem: remove all diseased leaves in autumn and shorten the branches where you can find infected shoots. It is only advisable to use fungicides when the same symptoms appear again next spring.
Aphid infestation is also quite common in robinia. If you recognize the pests early, it is often sufficient to spray the leaves with a hard water jet. If that doesn't help, you can try soapy water. To do this, dissolve a tablespoon of curd soap in a liter of lukewarm water and spray the leaves regularly.
Oil-based pesticides on which the aphids suffocate have also proven successful in practice. Alternatively, you can also place beneficial organisms such as hoverflies, lacewings or parasitic wasps on the robinia. However, there is always a risk that the beneficial organisms will look for their food on other plants than on the infected robinia.