OSR monitoring part of new CSFB project

Cabbage stem flea beetle (CSFB) migration monitoring will take place at a network of sites across England this autumn.

It is one of the first tasks in a new phase of research targeted at the management of this critical oilseed rape (OSR) pest, which also includes a survey of cover crop/catch crop usage.

The AHDB website will include weekly reports on adult CSFB migration at seven core monitoring sites, with the first report due by early autumn.

Migration data can help identify lower-risk drilling periods (especially after peak migration), but the ultimate ambition is to develop a decision support system that predicts the start, duration and intensity of migration.

In addition to regular counts of adult beetles caught in yellow water traps during the autumn, symptoms of crop invasion by larvae will also be recorded at the core sites.

Siobhan Hillman, who leads on CSFB monitoring at AHDB, said:

"When young crops encounter peak beetle migration, whole crops can be written off. This is particularly true when soil is dry. This autumn, weather forecasts will be even more critical to help set drilling dates. In sustained dry conditions, some may need to consider drilling after mid-September to avoid peak migration.

"Migration was muted last autumn, with only one monitoring site accumulating more than 100 adult beetles. It was the kind of autumn where some regretted not planting oilseed rape or not planting more of it, especially as we have seen some relatively high harvest 2025 yields. It will be interesting to see if last year’s low pressure impacts the intensity of migration this autumn."

Last year, Bayer launched an automated yellow water trap (MagicTrap) that catches insects and identifies and counts contents at regular intervals (using an integrated camera and artificial intelligence). MagicTraps, which have been supplied at no cost to the project, will be co-located at the core monitoring sites and used exclusively at several other monitoring sites.

In addition to generating data as part of a long-term effort to determine the factors that affect adult CSFB migration and improving trapping methods, the latest CSFB project will also:

• Test the field performance and timing of novel treatments (insecticides/biopesticides/synergists)
• Improve cultural control methods and guidance on their effectiveness (in isolation and combination)
• Generate guidance on how to encourage natural enemies of CSFB

As part of the work on cultural control methods, the project includes a survey on the general use of cover/catch crops. The results will help target project activity on the use of brassica-containing cover/catch crops (sown between cash crops), which may be able to lure CSFB away from nearby oilseed rape fields.

The survey (by the University of Reading/Rothamsted Research) comprises up to 12 questions (depending on how you answer) and should take no longer that ten minutes to complete (it is open until 31 August 2025).

The new project was recommended for funding by the AHDB Cereals & Oilseeds R&KE committee and will officially commence in autumn.

The results from the research will be used by AHDB to adapt the CSFB management strategies released by a unique industry partnership earlier this year.