After the ban of neonicotinoid seed treatment in winter oilseed rape in the European Union in 2013 emerging plants have no protection against insect damage. A primary autumn pest for which neonicotinoid seed treatments provided protection is the cabbage stem flea beetle, (Psylliodes chrysocephala L.). The imagines start migrating to oilseed rape crops in September. Maturation feeding on seedlings can cause stunting and poor plant vigour and even plant losses. Larvae start hatching from end of October until spring causing the main damage in Germany. They are mining within leaf petioles throughout the winter, which can lead to plant and seed yield losses. Aims of this study were to gain more knowledge on biology and damage potential of this pest with focus on impact of immigration time and beetle density in autumn and to improve prognosis of pest occurrence and damage potential.weiterlesen