Intensification of agriculture, with landscape simplification and reduction of natural habitats, is known to contribute to the decline of arthropods. Implementation of agroecological practices and infrastructures in current cropping systems is expected to mitigate this biodiversity loss and provide pest regulation through natural enemies. The aim of this study was to assess the efficiency of an undestroyed strip of winter cover crop within maize fields to promote ground-dwelling arthropod spillover and their predation activity into fields. The field survey was carried out in 2019 and 2020 within 12 fields. Monitoring of ground-dwelling arthropod activity-density, richness, and predation rate, as well as slug activity-density, was conducted in the strip, in the cropped area and in a grassy field margin. The results show that activity-density of carabids, spiders, and slugs, and the predation rate were overall higher in the strip than in the cropped area or the field margin. No clear edge effect of the strip on arthropods in the cropped area was found, but predation rate was enhanced closer to the strip. We did not record a negative effect of the strip on the occurrence of slugs within the maize crop. The study shows that a mid-field strip of winter cover crops can be efficient for biodiversity conservation of ground-dwellings predators in agricultural landscapes and provide a potential pest control service in cropped fields.