DNA metabarcoding of gut contents reveals natural predation by spiders on Xylella fastidiosa vectors in the southwestern Spain agroecosystem

Aim of study: To elucidate which species and specific guilds of spiders prey on vectors of Xylella fastidiosa from agroecosystems in southwestern Spain using metabarcoding approach. Area of study: Southwestern Spain. Material and methods: Spiders sampling was carried out on ground cover vegetation of olive, citrus and vineyard fields using a battery powered aspirator. DNA was isolated from each sample using E.Z.N.A.® Tissue DNA kit (Omega Bio-tek). A primer pair was designed to specifically amplify DNA from the following spiders’ potential prey belonging to the order Hemiptera: Philaenus spumarius, Neophilaenus campestris, Neophilaenus lineatus, Lepyronia coleoptrata, Aphrophora sp., Cicadella viridis, and Cercopis sp. Taxonomic assignment was conducted using the MetaCOXI reference database, based on the European Nucleotide Archive (ENA) and the Barcode of Life Data System (BOLD). Main results: Neophilaenus campestris was detected in two spider species: Enoplognatha caricis (Theridiidae) and Thanatus vulgaris (Philodromidae) (10.4% of the captured specimens). In addition, L. coleoptrata was preyed on by Haplodrassus macellinus (Gnaphosidae) (3.5%). In contrast, P. spumarius DNA was not detected in any of the spider samples. However, aphrophorid DNA was detected in the gut of spider collected in vineyards and citrus orchards but not in olive orchards. Concerning the spider guilds, aphrophorids were detected in the gut of “other hunters”, “ground hunters” and “space-web” spiders. Research highlights: Some species of spiders found in vineyards (50% of captured specimens) consumed N. campestris.