Annual flower strips under the ‘Sweden Blossom’ initiative – how do they perform for pollinators, natural enemies and herbivores?

Abstract Flower strips are an agri‐environmental measure to contribute to sustainable crop production by enhancing pollinators and natural enemies of pests. However, most strips are designed to target a single ecosystem service, often overlooking simultaneous effects on multiple functional groups of arthropods. In Sweden, large‐scale adoption of flower strips to promote pollinators through the ‘Sweden Blossom’ initiative represents an opportunity to deliver benefits beyond single goals, and to support multiple ecosystem services. We assessed how an annual flower strip mixture influences the pollinators targeted as well as the abundance of natural enemies and herbivores, their spillover 10 m into neighbouring crops and pest control. Pollinators were recorded via visual observations in the strips. Leaf‐dwelling arthropods were recorded with yellow sticky traps, and ground‐dwelling predators with pitfall traps in both the strips and adjacent spring barley fields. Natural enemies and herbivores in the crop were also assessed through tiller counts, while aphid predation rates were estimated using sentinel prey cards for leaf‐ and ground‐dwelling predators. The flower strips strongly increased pollinator abundances as intended but also increased the abundance of certain natural enemy and herbivore taxa, some of which also dispersed into neighbouring crops. However, arthropods present on crop tillers or pest control rates by leaf‐dwelling predators were not affected. Aphid predation by ground‐dwelling predators tended to increase in crop areas near the flower strips. These findings have implications for designing agri‐environmental measures, stressing the importance of context‐specific factors to maximise ecosystem service delivery and minimise potential unintended consequences.