The role of flower strips for field spider communities in a biodiversity-based agroecological system

Abstract: Flower strips are temporary undisturbed habitats that can be installed in
agroecosystems to counter the loss of biodiversity and associated services. The contribution of these habitats to pest control services has been documented but few studies have quantified their role as overwintering habitats and in the life cycle of field-active natural enemies controlling pests. In this study we examined the role of sown flower strips on ground-dwelling spider assemblages on the INRAE CA-SYS agroecological experimental platform (Dijon, France). Spiders were sampled with pitfall traps and emergence tents from March to July 2023 in seventeen flower strips and adjacent fields. Contrary to the literature, we observed a higher abundance of overwintering spiders in the fields compared to flower strips. Dominant species in fields were mainly agrobionts, spending their whole life cycle in the crops, but a substantial proportion of individuals were active in both habitats. Flower strips however supported a greater diversity of hunting strategies, which could be a key factor in the resilience and efficacy of pest control.