Ecological approaches to the control of pollen beetles in oilseed rape

At a time of increasing demand for rapeseed oil for biofuel and food use and as increasing areas are grown, the risk of pollen beetle resistance to pyrethroids presents a significant threat to the sustainability of the oilseed rape crop and to farm incomes. Measures are urgently required to reduce the use of insecticides against pollen beetles, to preserve activity of the limited armoury of insecticides and minimise environmental pollution. In this paper, the status of pollen beetle resistance to pyrethroid insecticides and current control methods are presented from a UK perspective. Three ecological approaches to the control of pollen beetles that are based on research into their behaviour and ecology and that of their natural enemies are highlighted: use of monitoring, trap cropping and conservation biological control. These approaches have the potential to significantly reduce insecticide use against pollen beetles by helping to identify when spray thresholds have been breached, reducing pest incidence in the crop and increasing populations of natural enemies, respectively.