Assessing the potential of biopesticides to control cabbage stem flea beetle Psylliodes chrysocephala

Pest Management Science
2023.08.25

Author: Claire Stéphanie Véronique Price, Heather Campbell, Tom William Pope

Citation: Price, Claire Stéphanie Véronique, Heather Campbell, and Tom William Pope. "Assessing the potential of biopesticides to control cabbage stem flea beetle Psylliodes chrysocephala." Pest Management Science (2023).

Abstract:

https://onlinelibrary.wiley.com/doi/abs/10.1002/ps.7746

Background

Cabbage stem flea beetle (CSFB) is an economically important pest of oilseed rape crops in Europe that was effectively controlled by neonicotinoid insecticide seed treatments until they were banned by the European Union in 2013. Since then, CSFB has been a difficult pest to control effectively, in part due to many populations having developed resistance to pyrethroids, the only authorized insecticides used to control this pest in many countries. Alternative solutions are therefore necessary, such as biopesticides. We tested an entomopathogenic fungus, three entomopathogenic bacteria isolates, two fatty acids and azadirachtin against CSFB adults under laboratory conditions. We also tested the efficacy of the pyrethroid insecticide lambda-cyhalothrin.

Results

Fatty acids were effective with up to 100% CSFB mortality after 24 hours. The entomopathogenic fungus Beauveria bassiana resulted in up to 56% mortality 14 days after treatment. Entomopathogenic bacteria formulations and azadirachtin were not effective (< 50% and <40% mortality, respectively). Results from a bioassay using lambda cyhalothrin indicated that the CSFB used in this study were resistant to this insecticide.

Conclusion

Entomopathogenic fungi and fatty acids could potentially be used to control CSFB as part of an Integrated Pest Management (IPM) programme. This study is the first to investigate the efficacy of different biopesticides to control CSFB under laboratory conditions. As such, these biopesticides require further testing to optimise formulation, application methods and to assess impact on non-target organisms. Finally, efficacy under field conditions must be determined to understand the influence of environmental variables.