Beetles 3 - 4 mm. Shiny blue-black. Legs with thickened thighs. Nymphs up to 7 mm, found in leaf stalks and later in the stem. Brown-black head, 3 clearly visible pairs of legs.
Beetle causes pitting corrosion on young leaves, only relevant in case of heavy feeding. Feeding activity of nymphs in leaf stalks and stems. Heavy infestation leads to increased wintering, broom growth and increased disease infestation (Phoma).
Visual control for leaf damage from emergence. In case of more than 10% of leaf damage up to the 4th leaf, a treatment is recommended.
Yellow trap control from sowing until the end of vegetation. If >50 beetles per yellow trap in 3 weeks, treatment is recommended. Most favorable date from the end of September into egg laying at the earliest.
At the end of vegetation, final inspection of yellow traps and petioles. Treatment normal stand: >5 larvae/plant, weak stand: >3 larvae/plant.
Good stubble cultivation and field hygiene.
Early sowing and thin stands show higher nymph numbers per plant.
Ground beetles and others decimate eggs and larvae.