A significant amount of research has documented how the adoption of agroecological practices at the field level can modify natural enemy communities and their biological control potential (Petit et al. 2020). Natural enemies are however mobile organisms that move beyond the field scale and the different species that form communities often present contrasting phenologies. Despite this, few studies have described the spatio-temporal dynamics of the different populations of natural enemies that co-occur in field, making biological control services difficult to predict (Tscharntke et al. 2016). In this study, we focus on the spatio-temporal dynamics of spider populations in cereal fields and adjacent sown flower strips. The experiment was conducted on the CA-SYS platform where disruptive biodiversity-based systems are being implemented that use no pesticide and are surrounded by of a dense mesh of grass and flower strips (Petit et al. 2021). From March 1st to July 5th 2023, fortnightly monitoring of spider populations was carried out in 17 winter cereal crops and their respective adjacent flower strip. In both habitats, overwintering individuals were monitored by emergence traps whereas circulating ones were monitored with pitfall traps. Here, we present the composition of spider communities in fields and in sown flower strips and describe the temporal dynamics of spider communities in the two habitats over time. We then focus on the dominant spider species and assess the respective and complementary roles of the two habitats in maintaining their populations. The identified patterns of habitat use are then linked to the life traits of spider species (hunting mode, motion strategy, body size) providing insights into their abilities to prey on crop pests.