Control flea beetle biologically
various species of beetles of the genus Phyllotreta
In our garden beds, the corrugated striped cabbage flea (Phyllotreta undulata) is the most common. It belongs to the leaf beetle family. It is named after the yellow stripes on its wing covers and its specially designed jumping legs that enable it to leap up like a flea. It is about 1.5 - 3 mm in size.
Its larvae are white and about 4 mm in size.
Life cycle of the leaf beetle
The adult beetles overwinter in hiding places on the ground. In spring, they eat more or less round holes in the leaves of young cabbage plants. Egg-laying takes place on the ground, and the larvae live in the soil, where they also pupate. In summer, the young beetles appear. These migrate to their winter quarters in early fall.
Damage caused by the ground flea
Damage to plants is caused by both the larvae and the adult earth fleas. The larvae feed on the lateral roots and root cylinder of cabbage plants. This results in barely noticeable damage. Beetle feeding on the leaves of young seedlings in spring, on the other hand, can lead to complete destruction of these seedlings in dry weather and inhibited plant growth. The young beetles in July cause considerably less damage. A typical damage pattern is the easily recognizable pitting of the leaves of the plants.
On which plants are flea beetle found?
Affected are cabbage plants such as arugula, cauliflower, Chinese cabbage, radishes, broccoli, kohlrabi and other cruciferous vegetables.
Control flea beetle with beneficial nematodes
Nematodes are tiny, filamentous soil organisms about 0.6 mm long. They are natural enemies of the ground flea. Certain nematode species specialize on the earth flea, among others, and can use its larvae for their own feeding and reproduction. The nematodes are supplied alive in a powder. For application, they should be mixed with water exactly according to package directions and applied to the affected areas.
Which stages of the flea beetle can I control?
From April to August, depending on the presence, the beetles and the larvae present in the soil can be controlled with nematodes.