The symptoms of cabbage root fly damage are almost always the same. The larvae eat the main root, causing it to turn brown at first. Eventually, it turns black and rots away completely. Damage can also be seen in the leaves. Since the root is damaged, they do not receive enough water and therefore wilt.
How to prevent (further) damage?
Avoid planting outside during the second half of April. Also ensure that the fly cannot lay its eggs near your plant. To do so, use a cabbage collar. This is a round or square piece of plastic or cardboard that protects the area around the stem of your plant. You can also repel the cabbage root fly using strong smells like dill, coriander or basil.
The cabbage root fly looks like a smaller version of the housefly. Do not be deceived by its size, as it can cause serious damage to your plants. The cabbage root fly lays its eggs a few centimetres from the plant stem. When the eggs hatch, the larvae burrow their way into the stem and tuck in. If this has happened, there is no real remedy anymore.
About cabbage root flies