Beetle 2.5-3 mm, grey-black. Eats a hole in the pod to lay its eggs, this hole is also used by the cabbage pod mosquito to lay its eggs. Larvae individually in pods. 4-5 mm, legless, whitish yellow with brown head. At maturity, the larvae often have holes visible. 1 generation/ year. The beetle does not cause any damage, but is important as a precursor for the cabbage pod mosquito. Larvae eat only a few ovules, but infested pods often become fungus.
Yellow trap records only the start of inflow. Infestation is determined by counting. Best in the afternoon when the sun is warm and the beetles are active.
Knock test on 5 bud stands in different areas of the plant. Beetles drop when disturbed and play dead.
Control target reached when 12 - 25 beetles are detected on 5 x 5 = 25 plants. Corresponds to 1 beetle/plant at low mosquito risk or 0.5 beetles/plant at known high mosquito risk.
Preserve beneficial organism potential. Ichneumon flies parasitise the larvae, ground beetles and rove beetles can decimate the larvae migrating into the soil to pupate.
If there are still young beetles in the field at harvest, the timely mulching of the rape stubble can decimate them
Cabbage seed weevil
Egg-laying site is also used by the cabbage brassica midge for laying eggs
Young beetles of cabbage seed weevil and cabbage stem flea often found at harvest time