Dataset for "Landscape composition and climate modulate the effect of flower strips on aphids and their natural enemies in sugar beet crops"

Agricultural intensification has reduced biodiversity and increased reliance on pesticides, creating an urgent need for sustainable pest-control strategies. Flower strips are widely promoted to enhance ecosystem services, yet their effectiveness remains highly context-dependent, which is poorly understood in major annual crops such as sugar beet (Beta vulgaris). Here, we tested when and where flower strips contribute to aphid suppression and natural-enemy enhancement across contrasting landscape and climatic contexts. Over two years (2022–2023), we monitored the colonization dynamics of two virus-vector aphids, Myzus persicae and Aphis fabae, together with five groups of ground- or foliage-dwelling natural enemies, including carabids, spiders, rove beetles, ladybirds and syrphid larvae, in 26 commercial sugar beet fields in northern France bordered by either sown flower strips or grassy strips. We assessed the effects of local strip type, landscape composition within 250-1000 m buffers, and climatic conditions during aphid pre-colonization, colonization and post-colonization periods. Flower strips did not consistently reduce aphid abundance as a main effect, but their effects strongly depended on landscape composition, climatic conditions and sampling period. Myzus persicae abundance was lower near flower strips in meadow- woodland-, cereal- and sugar beet-rich landscapes, whereas A. fabae abundance was reduced near flower strips in Fabaceae-rich landscapes and under higher mean temperatures, but increased in cereal-rich contexts. Natural enemies also responded strongly to strip type, but responses varied among taxa and landscape contexts. Our results show that flower-strip effectiveness depends on the match between local habitat management, landscape composition, climate and pest phenology. Rather than supporting uniform implementation, our study provides evidence for a targeted use of flower strips in agricultural landscapes, prioritizing contexts where they are most likely to enhance conservation biological control.