This dataset contains plot-level summaries of cavity-nesting predatory wasp food webs sampled in 80 forest plots of the main experiment in 2024. Layer nest traps were used to record realized antagonistic interactions among arthropod prey, predatory wasp hosts, and parasitoids across the tree-species richness gradient. The dataset includes plot identifiers, tree richness, canopy openness, brood-cell counts, observed prey, wasp, parasitoid and combined animal diversity, brood-cell-equivalent interaction frequencies, multitrophic interaction diversity, and prey-host network metrics. These data support analyses of how tree species loss and canopy openness are associated with predator diversity, trophic interaction frequency, multitrophic diversity, and food-web structure.

Standardized passive sampling across 80 forest plots in the BEF-China tree-diversity experiment. Layer nest traps were installed in plots spanning planted tree-species richness levels of 1, 2, 4, 8, and 16 species, with 24-species plots pooled with the 16-species level. Traps were exposed from May to July 2024 (included) and checked every three days for newly constructed brood cells; selected brood cells were sampled for prey and host larvae, and completed nests were retained for adult host and parasitoid rearing.

BEF-China experiment, near Xingangshan, Jiangxi Province, subtropical southeast China (117°54′ E, 29°07′ N).

Plot-level dataset summarizing layer-nest records from 80 BEF-China forest plots. Variables describe tree-species richness, canopy openness, predatory-wasp brood-cell counts, prey, wasp and parasitoid diversity, antagonistic interaction frequencies, multitrophic diversity, and prey-host network structure. Interaction frequencies are expressed in brood-cell equivalents.

Cavity-nesting predatory wasps, their arthropod prey, and associated parasitoids.

Plot-level summaries were derived from brood-cell records and species identifications. Diversity of prey, predatory wasps, parasitoids, combined animal communities, and antagonistic interactions was calculated as Hill numbers of order q = 0, 1, and 2. Interaction frequencies were expressed in brood-cell equivalents. Prey-host network metrics included connectance, weighted connectance, linkage density, predator generality, and network size. The manuscript analyses used generalized linear models, path analysis, and network analyses to relate these responses to tree-species richness, canopy openness, and site.