Assessing the potential of turnip rape and radish cover crops as trap crops for
Psylliodes chrysocephala
in commercial field production conditions
Anaïs Boulay, Antoine Gardarin, Alexandre Morisseau, Baptiste Labbe, Ivan Le Masson Abstract
BACKGROUND
Cabbage stem flea beetle (CSFB; Psylliodes chrysocephala ) is a major pest of winter oilseed rape (WOSR; Brassica napus ), during autumn. Previous studies have shown some species of Brassicaceae, for example, turnip rape ( Brassica rapa ) and radish ( Raphanus sativus var longipinnatus ), to be attractive for this pest. Farmers' crop rotations regularly include the use of cover crops before spring sowing to avoid leaving the soil bare and unprotected. As these cover crops are generally destroyed in winter, incorporating these Brassicaceae into cover crops mixes could: (i) attract CSFB and (ii) eliminate any larvae they may contain. The aim of this study was to assess the attractiveness of turnip rape and radish cover crops used by farmers. The study was carried out on 21 farms near Paris (France) during the autumn–winter of 2024. All farmers sowed winter oilseed rape, and most also established fields or strips of attractive Brassicaceae species (turnip rape or radish). Adult CSFB migration, adult feeding damage, and larval infestation were monitored across 55 fields.
RESULTS
Turnip rape fields/strips were the first to be colonized by CSFB, thereby potentially diverting part of the infestation away from WOSR fields. A greater amount of damage was observed on turnip rape and radish plants compared with WOSR plants. The most important factors explaining the difference in damage was attractive Brassicaceae plant density within the fields/strips and plant size.
CONCLUSION
These results demonstrate the potential of attractive Brassicaceae species grown as a cover crop to control CSFB. This effect was observed under commercial conditions, across a broad range of practices and pedoclimatic conditions, thereby reinforcing the potential of a ‘trap and destroy’ strategy. We also identify agronomic factors that can enhance Brassicaceae attractiveness. © 2026 Society of Chemical Industry.