Combining DNA metabarcoding and ecological networks to inform conservation biocontrol by small vertebrate predators

Abstract

In multifunctional landscapes, diverse communities of flying vertebrate predators provide vital services of insect pest control. In such landscapes, conservation biocontrol should benefit service‐providing species to enhance the flow, stability and resilience of pest control services supporting the production of food and fiber. However, this would require identifying key service providers, which may be challenging when multiple predators interact with multiple pests. Here we provide a framework to identify the functional role of individual species to pest control in multifunctional landscapes. First, we used DNA metabarcoding to provide detailed data on pest species predation by diverse predator communities. Then, these data were fed into an extensive network analysis, in which information relevant for conservation biocontrol is gained from parameters describing network structure (e.g., modularity) and species roles in such network (e.g., centrality, specialization). We applied our framework to a Mediterranean landscape, where 19 bat species were found to feed on 132 insect pest species. Metabarcoding data revealed potentially important bats that consumed insect pest species in high frequency and/or diversity. Network analysis showed a modular structure, indicating sets of bat species that are required to regulate specific sets of insect pests. A few generalist bats had particularly important roles, either at network or module levels. Extinction simulations highlighted six bats, including species of conservation concern, which were sufficient to ensure that over three‐quarters of the pest species had at least one bat predator. Combining DNA metabarcoding and ecological network analysis provides a valuable framework to identify individual species within diverse predator communities that might have a disproportionate contribution to pest control services in multifunctional landscapes. These species can be regarded as candidate targets for conservation biocontrol, although additional information is needed to evaluate their actual effectiveness in pest regulation.

Speeding up the detection of invasive bivalve species using environmental DNA: A Nanopore and Illumina sequencing comparison

“…As the library preparation procedures for Illumina‐based sequencing and MinION‐based sequencing are substantially different, we did not attempt to standardise the steps across platforms. Rather, we compared a MinION protocol that appeared to be working well in our laboratory at CIBIO‐InBIO (Portugal) with an Illumina protocol that has been used in numerous studies (Egeter et al, 2018; Martins et al, 2021; Mata et al, 2021; Peixoto et al, 2021). Initial PCRs to be sequenced with a MinION were performed with a final volume of 25 µl, containing 12.5 µl of Qiagen Multiplex PCR Master Mix (Qiagen, Germany), 0.75 µl of each primer (10 µM), 9.5 µl of ddH 2 O and 1.5 µl of eDNA on a T100 Thermal Cycler (BioRad, USA).…”

“…Rather, we compared a MinION protocol that appeared to be working well in our laboratory at CIBIO-InBIO (Portugal) with an Illumina protocol that has been used in numerous studies (Egeter et al, 2018;Martins et al, 2021;Mata et al, 2021;Peixoto et al, 2021).…”

Overcoming the pitfalls of merging dietary metabarcoding into ecological networks

“…Mata et al. (2021) highlighted the conservation biocontrol potential of bats in a Mediterranean landscape by reference to network structure and interaction frequencies. The study concluded that network ecology and metabarcoding provided a synergistic framework in which both individuals and communities can be assessed effectively in a biocontrol context.…”

“…Dietary metabarcoding is increasingly being applied to network ecology in a limited number of recent examples (Clare et al., 2018; Cuff, Drake, et al., 2021; Hemprich‐Bennett et al., 2021; Mata et al., 2021), but these are often isolated predator–prey interactions. However, dietary metabarcoding does theoretically facilitate the merging of complex multilayer networks including many types of interactions across multiple trophic levels, including interactions within trophic levels (i.e.…”

“…This study too applied network principles to dietary metabarcoding data, constructing networks entirely based on these data and using techniques from graph theory to understand the structure of the subsequent networks. Mata et al (2021) highlighted the conservation biocontrol potential of bats in a Mediterranean landscape by reference to network structure and interaction frequencies. The study concluded that network ecology and metabarcoding provided a synergistic framework in which both individuals and communities can be assessed effectively in a biocontrol context.…”