Identifying and developing Oilseed Rape varieties which deter cabbage stem flea beetle

Cabbage stem flea beetle is a significant crop pest, which can devastate oilseed rape.

UK crop losses due to cabbage stem flea beetle were estimated at 5.4% in 2016/17 equivalent to 31,000 ha-1 and as high as 15% for some counties. Losses in yield of up to 20% have been reported with farmers choosing to plough in the crop if damage is too great.

This pest is becoming increasingly problematic since the withdrawal of neonicotinoid-based pesticides which were previously used for control. As such, growers and breeders of oilseed rape have expressed their concerns over this pest and what it could mean for the future of UK oilseed rape.

The John Innes Centre has the benefit of an outstanding Entomology department which has allowed us to develop the first in house breeding population of cabbage stem flea beetles, enabling us to conduct research into their life-cycle and feeding preferences.

Discussions between our scientists and industry have led to the development of two PhD research projects which use our breeding population of the cabbage stem flea beetle with the aim of targeting findings to develop integrated pest management approaches. One PhD project is funded by Limagrain, the other by the Agriculture and Horticulture Development Board (AHDB).

While we are still at a relatively early stage in this research one of our key findings to date is the identification of two oilseed rape lines which are less palatable to adult flea beetle.

Impacts to date

  • Entomology Dept set-up the first in house breeding population of the cabbage stem flea beetle for research purposes
  • We have identified entomopathogenic fungi (with Warwick and ADAS) and a parasitic wasp (with Natural History Museum, London, Swedish Museum of Natural History) which could be investigated for control of cabbage stem flea beetle
  • Two lines of oilseed rape have been identified which adult flea beetles find unpalatable in the lab. These results have been confirmed in field trials

Industry engagement is a crucial two-way process for these projects, allowing PhD students Jessica Hughes and Lucy Thursfield to discuss on-farm beetle behaviour with farmers as well as allowing them to collect new beetles for the insectary.

Farmers and breeders are also excited by the results, with our scientists receiving regular requests to participate in industry conferences and meeting such as Croptec Show and OREGIN meetings.

Having identified flea beetle resistant lines our research is now focusing on which genes and compounds are responsible for this resistance. Identifying markers for these genes will allow plant breeders to incorporate these genes into varieties of oilseed rape that are under development.

Anticipated future impact

  • Identifying markers for use by the plant breeding industry
  • High throughput assays for cabbage stem flea beetle feeding preference/tolerance
  • New varieties developed with improved resistance to cabbage stem flea beetle
  • Growers experience higher yields from improved varieties
  • Maintenance and expansion of oilseed rape as a valuable break crop in the UK

In the Genes in the Environment research programme, regular engagement with industry allows us to get an understanding of the most important challenges faced by growers and industry. Tackling cabbage stem flea beetle was identified as a major challenge for the growers of oilseed rape.