Effects of regional crop rotations on autumn insect pests in winter oilseed rape

• Published in: Pest management science Vol. 80; no. 5; pp. 2371 - 2382
• Main Authors: Hausmann, Johannes, Heimbach, Udo, Gabriel, Doreen, Brandes, Meike
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.05.2024; Wiley Subscription Services, Inc
• Subjects: Agricultural practices; aphids; Autumn; Chemical control; Crop rotation; Delia radicum; dispersal capacities; Distance; Infestation; Insect control; Insect pests; Insecticide resistance; Insecticides; Insects; integrated pest management; Oilseed crops; Oilseeds; Pest control; Pests; Plant protection; Pressure; Probability theory; Psylliodes chrysocephala; Rape plants; Rapeseed; Risk assessment; spatio‐temporal analysis; Winter; Delia radicum; spatio‐temporal analysis; Psylliodes chrysocephala; aphids; dispersal capacities; integrated pest management
• ISSN: 1526-498X; 1526-4998
• DOI: 10.1002/ps.7716

Background Chemical control of insect pests in oilseed rape (OSR) is becoming increasingly difficult due to the development of resistance and restrictive insecticide approvals in Europe. At the same time, there is a lack of preventive and alternative control measures. Crop rotation mostly fails to control insects due to their mobility; however, changing regional cropping densities can dilute or concentrate pest pressure. In this study, we investigated whether the local occurrence of Psylliodes chrysocephala and Delia radicum, serious insect pests in winter OSR, is influenced by distance from the previous year's OSR fields and how changes in OSR rape cropping density at a regional scale (up to 10 km radius) affect pest pressure. Results Abundance of P. chrysocephala in yellow water traps decreased with increasing distance to previous year's OSR. Estimated catches in the first 3 weeks of migration were about 68–76% lower at 10 km distance compared to 1 km in autumn 2019 and 2020. However, in both seasons P. chrysocephala was able to disperse over distances of 10 km. Probability of root damage by D. radicum was affected by changes of OSR cropping area at a spatial scale of 2.5 km radius; it increased if acreage of OSR decreased. Furthermore, aphid infestation was lower when OSR was distant in the previous year. Conclusion This study could enable field‐specific risk assessment and prediction of pest pressure. To decide about the effectiveness of cropping breaks at a regional level as a preventive crop protection measure, more knowledge on other pest species and antagonists is needed. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. Pest abundance of the cabbage stem flea beetle (Psylliodes chrysocephala) declined with increasing distance to oilseed rape (OSR) cropping area of the previous year, whereas changes in OSR cropping area affected abundance of the cabbage root fly (Delia radicum).