Wild plant biodiversity for conservation biological control of predators in horticultural crops

Conservation biological control (CBC) enhances natural enemies through habitat manipulation, requiring detailed knowledge of their trophic and structural needs, particularly regarding wild vegetation. This study examined the spatial and temporal occurrence of six predatory arthropods—Orius insidiosus, coccinellids (Eriopis connexa, Cycloneda sanguinea), hoverflies (Allograpta exotica, Toxomerus duplicatus), and Neoseiulus californicus—across 12 wild plant species on agroecologically managed horticultural farms in Argentina. Sampling was conducted biweekly from May 2022 to April 2023 in “patch” and “edge” locations adjacent to crops. Generalized Linear Models showed strong, positive associations between natural enemies and several variables. O. insidiosus presence was associated with thrips, spring, and flowering; coccinellids with aphids and spring/summer/autumn; and hoverflies with aphids, spring/autumn, flowering, and patch locations. N. californicus frequently occurred on Helminthotheca echioides, Sonchus oleraceus, and Carduus acanthoides even without prey, suggesting alternative resources or refuge. Several plant species, including Dipsacus sativus, Galinsoga parviflora, and Urtica urens, provided essential refuge and food resources during the resource-limiting winter season, while native species such as G. parviflora and Amaranthus hybridus provide multifunctional ecosystem services beyond pest control. Findings support integrating specific wild plants into CBC strategies to sustain trophic-resource continuity across seasons and promote pest regulation in functional horticultural landscapes.