Mosquito with 1.5-2 mm very small and inconspicuous. Bad flyer, therefore concentrated on the edges of the fields. Usually only active from middle/end flowering in places sheltered from the wind. Larvae 2 mm long, legless and headless. pupating in the ground, hatching and development of a 2nd and sometimes 3rd generation.
Mosquito harmless, but larvae suck on inner pod walls. Pods burst open prematurely and fungus. Margins and main shoot are most affected.
Hardly to control, because mosquito is not detected via yellow trap. Mosquito is also easy to confuse with ichneumon flies.
Exploits cabbage seed weevil oviposition sites, therefore indirect control of the midge through treatment. Midge can bite very young pods but also directly!
Small fields and sheltered locations more heavily infested, concentrated on large fields - especially to previous year's rapeseed. Edge treatment often sufficient.
Appears mostly after the optimal Sclerotinia control date. Additional late passage usually uneconomical.
Larvae can no longer be controlled.
The most important natural enemies are ichneumon flies, ground beetles on the ground as well as nematodes and soil fungi.
Turning tillage buries part of the mosquito cocoons.