Here you can find out more about the damage caused by the cabbage fly and how to successfully prevent and control the small whitefly.
Cabbage Fly Symptoms
Many hobby gardeners have experienced a nasty surprise during the cabbage harvest. The vital head of cabbage is harvested in autumn and should be prepared at home. Only when cutting up the cabbage do you suddenly encounter feeding channels filled with small maggots. Sometimes the disappointment is not that big, because you can see from the outside of the plant that something is not quite right with it. Affected plants are often underdeveloped and may begin to wilt. In particularly severe cases, the entire cabbage can rot because the maggots' feeding ducts are entry points for putrefactive diseases. The pest particularly targets young plants and cauliflower. Basically, however, all cabbage plants can be infested.
Pathogen
The small cabbage fly (Delia radicum) is usually responsible for the damage. Its larger relative, the cabbage fly (Delia floralis), is less common. Around the beginning of the horse chestnut blossom (end of May), the small cabbage fly wakes up from its hibernation and looks for suitable plants to lay its eggs. The fly relies on visual stimuli and the typical smell of cabbage. The cabbage fly has specialized in cabbage plants because its maggots can easily digest mustard oils, which are poisonous to insects. So the cabbage fly only has to share its food with a few other specialized insects.
After laying up to 100 eggs per female, the larvae hatch on the root neck of the cabbage plants and eat through the roots. Only the second and third generation of larvae have their eyes on the succulent veins of the cabbage leaves. Even cauliflower florets sometimes get it on their collars.
Cabbage Fly: Preventive Measures
Because probably no hobby gardener would like cabbage with amaggot supplement, the preventive measures are very important. With a few cabbage plants, so-called cabbage collars are suitable for repelling the cabbage fly. You can also easily make cabbage collars yourself from felt. To do this, simply cut out a 15 to 20 cm disk from thick felt and then cut a slit from the center to the edge. Then place the disk around the root collar of the cabbage plant so that the root collar at the slit end is in the center of the disk. This effectively prevents infestation by the maggots. An even more practical method is the use of close-meshed vegetable protection nets. Although these nets are a bit expensive to buy, they also keep other pests such as cabbage whites away in addition to cabbage flies. If the net is consistently left on the cabbage plants from planting to harvest, infestation is practically impossible.
The following products have proven themselves in our garden:
- Insect nets: reliably protect your plants from damage by insects
The meshes of the net must of course be intact and the net must lie properly on the ground. In addition, you should generally pay attention to a varied crop rotation, since the flies often overwinter in cabbage harvest residues.
Control of cabbage fly
Since the larvae of the cabbage fly belong to the mining insects, combating them is actually not possible (mining: pests feed on the plants and a typical feeding channel is created). Even in commercial horticulture, combating it with chemical agents is difficult. The reason for this is that the larvae are protected by the plant in their feeding channels and the pesticide has little or no effect there. Nevertheless, you should not lose interest in growing cabbage because of this, because if the preventive measures are observed, nothing should stand in the way of a successful cabbage harvest.
It is not only cabbage flies and cabbage whites that damage cabbage plants, fungi also often cause considerable damage. In this article you will find out how to recognize clubroot infestation and how to combat the fungal disease.