MEDITERATRI project - assessing the trophic ecology of predatory arthropods in Mediterranean agriculture via DNA metabarcoding diet analyses

Abstract

A type of management and the use of pesticides in arable land may negatively affect a range of soil biota and thus their food webs important for ecosystem functioning. By analysing trophic interactions we could reveal the extent of potential benefits that certain organisms can provide in biocontrol and maintaining healthy ecosystems. To evaluate the role of predatory arthropods within olive orchards and vineyards under Integrated Pest Management (IPM) and Ecological Pest Management (EPM) we collected carabid beetles together with other dominant predatory arthropods in the field (e.g. ladybugs, antlions, spiders, centipedes) and subdued the individuals to molecular gut content analyses using NGS. DNA metabarcoding diet analysis approach allowed detecting a wide variety of taxa from gut contents of the predators. In addition, using ICP-MS and LC-MS/MS we quantified Cu, pesticides and its residues in soil and animals representing different trophic guilds. Since concentrations of some toxic compounds detected in carabids body were negatively correlated with those in the soil, we aim to identify a potential vector for possible transfer of toxicants to general predators via predation. The results contribute to the risk assessment of proliferation of detected chemical compounds including copper in the ecosystem and to the knowledge on the overall field sustainability of predatory invertebrates to maximize their role in pest control. The study was conducted under the project activity of HRZZ – Mediteratri.