Wild plants as a source of natural enemies: some thoughts on the occurrence of predatory mites (Acari Phytoseiidae) in a vineyard and in a nearby hedge

Abstract

A survey of the mite fauna in a vineyard and in a nearby hedge, the last made up of different species of wild plants, was carried out on a farm in North-Eastern Italy (Veneto region). During a 3-year study, mites belonging to the Tetranychidae, Tydeidae and Phytoseiidae families were found to be particularly abundant. Their population dynamics were studied on the grapevine and on the most common wild plants in the hedge; the specimens belonging to the Phytoseiidae and Tetranychidae were identified. Five species of phytoseiid mites were found in the vineyard: Typhlodromus pyri Scheuten was the dominant species; Amblyseius aberrans (Oudemans), Phytoseius plumifer (Canestrini & Fanzago, sensu Chant, 1957) and Amblyseius andersoni (Chant) were frequently collected, while Amblyseius finlandicus (Oudemans) was rarely recorded. The spider mite populations present in the vineyard, mainly Eotetranychus carpini (Oudemans), were efficiently controlled by phytoseiids. On the wild plants surrounding the vineyard, 15 phytoseiid species were found: A. aberrans, A. andersoni, A. finlandicus, A. rademacheri Dosse, A. reductus Wainstein, A. aff. messor (Wainstein), A. aff. aberrans, Typhlodromus aceri Collyer, T. bakeri (Garman), T. pyri, T. tiliarum Oudemans, one unidentified species of the genus Typhlodromus, P. plumifer and two unidentified species of the genus Phytoseius. A. andersoni, A. finlandicus and A. aff. aberrans were the most abundant species on the wild plants while A. aberrans, T. pyri and P. plumifer were collected less frequently or rarely.