Landscape features, garden management, and microhabitats influence prey removal and predator composition in urban agroecosystems

• Published in: Biological control 2024-01, Vol.188, p.105426, Article 105426
• Main Authors: Philpott, Stacy M., Bichier, Peter, Fowler, Robyn, Jha, Shalene, Liere, Heidi, Lin, Brenda B.
• Format: Article
• Language: English
• Subjects: Agroecosystem; Biodiversity; Heat island; Mulch; Natural enemy; Urban
• ISSN: 1049-9644
• DOI: 10.1016/j.biocontrol.2023.105426

•Ants were the most abundant predator observed in urban gardens.•Egg removal was higher under vegetation compared to bare and mulched open areas.•Prey removal increased with floral abundance, but declined with tree abundance.•Plant richness and urban cover influenced predators, but not predation. Agroecosystem management at microhabitat, habitat, and landscape scales shapes natural enemy communities, with critical implications for ecosystem services. Yet few studies examine the impacts of small to large scale habitat management features on predator communities, abundance of predator species, or removal of prey items from urban agroecosystems. In this study, we used observations and a sentinel prey removal experiment to examine the impact of substrate (prey placed on the ground vs. on kale plants), microhabitat (prey placed under vegetation, on bare soil in open areas, or on mulch in open areas), local garden management features, and landscape features on predator species composition and removal of two prey species in urban gardens in the California central coast. We found that both microhabitat characteristics and substrate type shaped prey removal rates within urban gardens, and microhabitat, but not substrate, impacted predator species composition. In addition, both garden management (floral abundance, herbaceous plant richness, and tree and shrub abundance) and landscape features (urban land cover within 2 km) influenced prey removal and predator composition. Nearly all prey removal of eggs was accomplished by ants; larvae predators were more diverse and included ants, birds, lizards, wasps, and spiders. Although predator composition was mediated by many habitat features, prey removal was greater under vegetation, from the ground, when floral abundance in gardens was high, and in gardens with fewer trees and shrubs. Considering how these different management features affect predator foraging behavior and interactions will be a promising next step in this field.