Wasp 6-8 mm large, chest and abdomen yellow-orange colored. Head and sides of the chest black. Wings with black edge. Nymphs initially grey-green, later black-grey. Three pairs of sternum and eight pairs of anal feet. 2 to 3 generations.
Only dangerous in mass occurrence, then growth and feeding damage increases very quickly. Window-, hole- or edge-eating. Later leaves are eaten down to the leaf veins (skeletal feeding).
Often, but not always, found in yellow traps. However, control for larval infestation must be carried out on the undersides of the leaves!
Individual parts of the rapeseed fields may be affected earlier and more severely, depending on the direction of approach.
Up to 4-leaf stage 10% leaf area damage, thereafter 1-2 caterpillars/plant.
Insecticides against biting insects have sufficient effect. React quickly if there are many small caterpillars.
Partial reduction of pupae (up to 5 cm in the soil) through soil cultivation in the rape seed after harvest.
Lower stand density usually means higher numbers of grubs / roots. Recommended minimum sowing rate 40-50 germinable grains/m².
Predatory beetles decimate eggs and maggots.
Nymph parasitisation by ichneumon flies and others.
Young caterpillar on the underside of leaf.
Turnip sawfly dangerous only in case of mass occurrence