The number and type of natural enemies of crop pests found in winter-sown oilseed rape fields (Brassica napus L.) in relation to local plant diversity (in crop and field margin) and landscape characteristics. Natural enemies and pests were collected using two methods (suction sampling and pitfall traps). Local plant diversity was assessed using quadrats in field margins and in cropped area. The presence of hedges was also recorded. Landscape characteristics include the amount of mass flowering crops, arable land, presence of patches of different grassland types (intensive, restored and species rich) and the amount of grasslands and other semi natural habitat with up to a 3km radius of the collection points. These data were collected as part of Wessex BESS project, funded by the NERC Biodiversity and Ecosystem Service Sustainability research program. This dataset can be used in conjunction with other Wessex BESS WP4 datasets.