Data from: Plant-derived environmental DNA complements diversity estimates from traditional arthropod monitoring methods but outperforms them detecting plant-arthropod interactions

Our limited knowledge about the ecological drivers of global arthropod
decline highlights the urgent need for more effective biodiversity
monitoring approaches. Monitoring of arthropods is commonly performed
using passive trapping devices, which reliably recover diverse
communities, but provide little ecological information on the sampled
taxa. Especially the manifold interactions of arthropods with plants are
barely understood. A promising strategy to overcome this shortfall is
environmental DNA (eDNA) metabarcoding from plant material on which
arthropods have left DNA traces through direct or indirect interactions.
However, the accuracy of this approach has not been sufficiently tested.
In four experiments, we exhaustively test the comparative performance of
plant-derived eDNA from surface washes of plants and homogenized plant
material against traditional monitoring approaches. We show that the
recovered communities of plant-derived eDNA and traditional approaches
only partly overlap, with eDNA recovering various additional taxa. This
suggests eDNA as a useful complementary tool to traditional monitoring.
Despite the differences in recovered taxa, estimates of community α- and
β-diversity between both approaches are well correlated, highlighting the
utility of eDNA as a broad scale tool for community monitoring. Last, eDNA
outperforms traditional approaches in the recovery of plant-specific
arthropod communities. Unlike traditional monitoring, eDNA revealed
fine-scaled community differentiation between individual plants and even
within plant compartments. Especially specialized herbivores are better
recovered with eDNA. Our results highlight the value of plant derived eDNA
analysis for large-scale biodiversity assessments that include information
about community level interactions.