Fig 1.
Setup of field experiment and regurgitate sampling.
(A) Overview of plots of the Trait-Based Experiment with enclosures. (B) Enclosures were made of construction foil sunk into the soil using PVC panels. (C) Marked beetles were released and recaptured to sample regurgitates (D) sampling regurgitates. Photographs by J. Tiede.
Table 1.
Organisms detected with NGS in regurgitates of P. melanarius, sorted by their most likely type of interaction with the beetle.
Table 2.
Summary of generalized linear model results on the effect of plant species richness, plant functional diversity and percent vegetation cover on the number of OTUs detected in each interaction group.
Fig 2.
Effects of plant species richness, plant functional diversity, and percentage vegetation cover on feeding interactions and neutral interactions detected in regurgitates of P. melanarius.
Points represent individual plots and are scaled based on the logarithm of the number of sequences, blue lines show GLM predictions, blue polygons show 95% confidence intervals for effects with p<0.05, red lines and red polygons refer to GLMs weighted by the number of sequences. A) Total number of feeding interactions including prey and plant taxa, B) feeding interactions involving plant taxa, C) feeding interactions involving total prey taxa, D) feeding interactions involving intraguild predation, and E) neutral interactions.
Fig 3.
Effects of plant species richness and plant functional diversity on detection frequency of abundant OTUs detected in regurgitates of P. melanarius.
The six panels show the three kingdoms (Plantae, Animalia, and Fungi). Points represent OTUs, aggregated at family level, that were detected in at least two levels of plant species richness. Lines (smoother span = 1.6) show least-squares fits for illustrative purposes only.
Fig 4.
Mites as prey and parasites of P. melanarius.
(A) Predatory mite (Trombidiformes: Trombiculidae) in a plot of the Jena-Experiment. (B) Mite isolated from a gut of P. melanarius (C). Phoretic mites (Mesostigmata: Parasitidae) on P. melanarius. Photographs by C. Scherber.