TY  - JOUR
T1  - Why Biological Control Works Unevenly across Agroecosystems: A Realist Review of Traits, Trophic Context, Landscape Structure, and Management History
A1  - Daniel Fischer
A1  - Laura Meier
A1  - Thomas Braun
A1  - Stefan Koch
A1  - Felix Roth
JF  - Entomology and Applied Science Letters
JO  - Entomol Appl Sci Lett
SN  - 2349-2864
Y1  - 2025
VL  - 12
IS  - 1
DO  - 10.51847/nnKDf0M6hL
SP  - 8
EP  - 16
N2  - Biological control is increasingly expected to reduce pesticide dependence while sustaining crop protection, yet apparently similar interventions often produce different outcomes across agroecosystems. The central evidence gap is not whether natural enemies can suppress pests, but why particular agents, assemblages, and habitat or management interventions generate effective, stable control in some settings and weak, transient, or counterproductive effects in others. This Original Realist Review Article examines that problem through context–mechanism–outcome reasoning. It integrates evidence concerning natural-enemy traits and functional performance, trophic complexity and intraguild interactions, landscape structure and resource continuity, and management history and ecological legacy effects. The strongest defensible synthesis is that biological-control performance is an emergent property of configurations rather than an intrinsic property of an agent or intervention. Traits influence encounter, establishment, persistence, and attack only after being filtered by prey or host characteristics, interaction networks, resource distributions, disturbance histories, and deployment conditions. Diversity can support control when functional roles are complementary, but species richness alone does not establish complementarity; similarly, laboratory attack rates do not establish field suppression or crop protection. Interpretation is limited by heterogeneous trait definitions, mismatched spatial and temporal scales, reliance on abundance or attack proxies, incomplete trophic networks, bundled management categories, and limited prospective testing of proposed mechanisms. Biological-control design should therefore begin with an explicit intended outcome and a testable programme theory, identify rival mechanisms and failure pathways, and measure the full chain from agent performance to pest suppression and crop response. Progress depends on comparative, multi-context studies that treat uncertainty, non-target effects, and transferability as design requirements rather than post hoc qualifications.
UR  - https://easletters.com/article/why-biological-control-works-unevenly-across-agroecosystems-a-realist-review-of-traits-trophic-con-gecewzhomzhnxuk
ER  -