Overwintering arthropod assemblages across and within habitats of a Swiss agricultural landscape

Abstract: Semi-natural habitats (SNHs) are known to support high levels of biodiversity within agricultural ecosystems. Management of SNHs in agricultural landscapes should seek to increase arthropod diversity and optimize ecosystem functioning and services, such as natural pest control through high predator abundances. Emergence traps were used to sample overwintering arthropods in Swiss lowlands in order to determine which habitat types are important for promoting high diversity and abundance of overwintering arthropods. Woody habitats proved to be valuable in supporting high predator abundance, herbaceous habitats supported lower predator and higher herbivore abundances, while crops supported the lowest density of overwintering arthropods. Woody habitats should be promoted in agroecosystems in an effort to maximize arthropod diversity and predator abundance. By supporting high abundance of predators they can fulfil multiple objectives. It is therefore recommended that existing hedgerows are conserved and their value enhanced by targeted planting of new hedgerows to connect existing overwintering habitats.