Investigating non-chemical control options for cabbage stem flea beetle in oilseed rape

Abstract: Cabbage stem flea beetle (CSFB; Psylliodes chrysocephala) remains a serious and intractable problem for winter oilseed rape (WOSR) growers in some parts of the UK. CSFB adults feed on the foliage of emerging crops and can threaten establishment. They lay their eggs at the base of plants and the larvae mine the petioles from mid-October before moving into the stems in spring. Losses due to CSFB in 2016/17 were estimated at 9% of the national crop (> 33,000 ha) (Wynn et al., 2017). In autumn 2016, ADAS (in collaboration with Fera Science Ltd., Cotton Consultancy, Bayer CropScience Ltd. and Syngenta UK Ltd.) began a 40-month AHDB Cereals & Oilseeds-funded project investigating integrated pest management of CSFB in WOSR. The project aims to develop an effective IPM strategy by further understanding the biology of the pest and its relationship with its environment. This paper presents selected results from the first two years of the project. An objective of the project is to assess two non-chemical options for CSFB. The first investigates whether grazing (or defoliating) WOSR during the winter can control CSFB larval populations. The second investigates the use of volunteer OSR (vOSR) as a trap crop for adult CSFB.