Natural enemies emerging in cereal fields in spring may contribute to biological control

Biological pest control is known to depend on landscape heterogeneity. However, such relationship shows irregular pattern and seems influenced by local farming practices natural enemies that overwinter within crop fields. The objective of this study was assess the contribution emerging in spring biological control, their response interaction between heterogeneity intensity. We monitored overwintering insect community using emergence traps measured potential predation prey cards 30 cereal fields, France. Study fields were selected along a gradient recorded. None 10 taxa lepidopteran eggs or weed seeds. On ground, aphid positively correlated with carabid beetles. foliage, negatively parasitoids. Overall, overwinters seemed benefit from landscape-scale lower diversity higher edge density combination local-scale intensities. This suggests they represent subset species adapted intensified systems. highlights broad taxonomic range predation.