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Pesticides constitute a major threat to biodiversity, but our understanding of the complex interactions between local and landscape factors influencing their distribution in agroecosystems remains limited. We conducted a pioneering study where we screened spiders, rodents, plants and soils for multiple pesticide residues in perennial crops (orchards and vineyards) managed under organic (N = 8) and integrated pest management (N = 8) systems. We then quantified the proportional representation of major habitat types in surrounding landscapes. Additionally, we conducted interviews with farmers to gain precise insights into pesticide applications. We expected that landscape factors would be more important for mobile entities (i.e. spiders and rodents), while management type would be relatively more important for the sedentary entities (i.e. soils and plants). We detected various pesticides within studied crop types, including several forbidden in the European Union. We found that pesticide distribution in spiders was influenced by the proportion of semi‐natural habitats in the landscape, with pesticide concentration decreasing as the proportion of semi‐natural habitats increased. Additionally, we observed that the spectrum of pesticides in spiders increased with the dominance of web‐building spiders. In contrast, pesticide levels in rodents were not affected by either landscape composition or local management type. For plants, pesticide distribution was affected by the proportion of forests and shrublands and, to some extent, by local management practices. In the case of soil, pesticide distribution was primarily determined by local management. This study marks an effort in demonstrating that both local and landscape factors play crucial roles in shaping pesticide distribution within perennial crops. Importantly, the relative importance of these factors varied across the four matrices investigated. Synthesis and applications: To comprehend the factors that determine pesticide distribution in crops, it is crucial to monitor diverse ecosystem components rather than focusing on a few model species. This approach underscores the necessity for ecologically sensitive management at landscape scale. Such management should involve the preservation and enhancement of (semi)natural habitats around crops. These combined insights can form the foundation for conservation and management initiatives aimed at mitigating the impact of pesticides on biodiversity within crops. [ABSTRACT FROM AUTHOR]

Temporal change in vegetation complexity and field management may interactively affect the structure of predator–prey networks in agroecosystems and consequently alter the biocontrol potential of predators. There is a limited number of studies that have addressed these questions for generalist predator–prey networks.We investigated how vegetation complexity during crop development and management type (conventional vs. organic) affect the trophic networks of orb‐weaving spiders and their prey in rainfed lowland rice ecosystems in southern Thailand. Specifically, we investigated orb‐weaving spiders and prey composition, prey selectivity and network structure.Overall, orb‐weaving spiders captured mostly detritus‐associated Diptera, aquatic‐associated Ephemeroptera and Hemiptera pests. The increasing vegetation complexity during rice development significantly restructured the network of orb‐weaving spiders and prey, while field management had only a marginal effect. The increased vegetation complexity during rice development led to an increased number of weak trophic interactions in comparison to few but strong interactions in simple vegetation.Our results indicate that increasing the number of spider species per prey taxon (prey vulnerability) in late rice season may enhance their top‐down control of prey including rice pests. This study also highlights that the network complexity and the stability of rice ecosystems increased during the rice growing season as the vegetation became more complex.Future practices could look for a way to support the densities of detritus and aquatic insects and to artificially increase habitat complexity during the early stage of rice development to improve the biocontrol services provided by the orb‐weaving spiders. [ABSTRACT FROM AUTHOR]

Intraguild predation (IGP) is a common interaction between generalist predators when they competitively exploit similar resources and prey on each other. Theoretical models predict limitations for intraguild predator coexistence unless some mechanisms, such as the utilization of alternative prey (i.e. trophic niche partitioning) and cannibalism, increase the relative intraspecific clustering and interspecific segregation. As hunting strategies determine trophic niches of predators and their own vulnerability to predation, the hunting strategies may also determine the relative importance of cannibalism, predation, and exploitative competition and consequently the intensity of IGP. The importance of hunting strategies on the potential outcome of IGP and how habitat properties modify the interaction between hunting strategies remain poorly understood. Using published data on spider prey of spider predators, we first investigated how predation of a top‐predator on a mesopredator is determined by the functional distance between both predators to understand how predation and exploitation are distributed in spider communities. Subsequently, we investigated the predation among spiders with particular hunting strategies to understand which strategies interact most frequently. We also investigated whether the interaction between hunting strategies was influenced by habitat type (forest, open (semi)natural habitat, agroecosystem) or by habitat stratum (ground versus vegetation). The hunting strategies of top‐predators and mesopredators interacted to determine the relative capture proportions of conspecifics and hetero‐specifics. This interaction was further modified by habitat type and stratum. Two mechanisms can reinforce coexistence in highly diverse spider communities. First, top‐predators preyed most frequently on functionally distinct mesopredators, which indicates the overall intensity of IGP may be relaxed by a balanced distribution between exploitative competition and predation. Second, cannibalism was common for top‐predators with a hunting strategy of frequently preying on functionally similar mesopredators. Cannibalism may lead to self‐limitation of top‐predator populations and may thereby facilitate coexistence between two predator species. [ABSTRACT FROM AUTHOR]