TY  - JOUR
JF  - Acarologia
T1  - Seasonal abundance of predatory mites in vineyards treated with insecticides: trends in north-eastern Italy
VL  - 66
IS  - Suppl
SP  - 220
EP  - 220
PY  - 2026
SN  - 0044-586X
SN  - 2107-7207
PB  - Les Amis d'Acarologia
AU  - Ahmad M., Dayoub
AU  - Enrico, Marchesini
AU  - Sergio, Carraro
AU  - Lisa, D’Ambrogio
AU  - Nicola, Menato
AU  - Alberto, Pozzebon
AU  - Carlo, Duso
UR  - https://doi.org/10.24349/uh8d-9ogl
DO  - 10.24349/uh8d-9ogl
DA  - 2026-07-20
ET  - 2026-07-20
KW  - Predatory mites
KW  - Biological control
KW  - Insecticide impact
KW  - Seasonal abundance
KW  - Integrated pest management
AB  - European vineyards are dominated by generalist predatory mites (mainly Acari: Phytoseiidae), whose populations contribute to effective biological control of tetranychid mites, preventing their outbreaks. In Italy, the mandatory control of Scaphoideus titanus, the vector of Grapevine Flavescence dorée phytoplasma (FDp), requires the application of broad-spectrum insecticides, which may disrupt populations of predatory mites, reducing their biocontrol potential. This study investigated the seasonal abundance of phytoseiid mites before and after insecticide applications in northeastern Italy. Surveys were conducted in 2025 across 30 vineyards in the Veneto region, northeastern Italy. At each site, phytoseiid density and species composition were assessed on four sampling dates during the growing season: two dates before insecticide applications (2-3) and two after them. For each assessment, 40 leaves were collected (four replicates of 10 leaves) and then examined under a stereomicroscope; mites were counted, collected, mounted in Hoyer’s medium, and identified under a phase-contrast microscope using relevant literature and dichotomous keys. Phytoseiid populations occurred in all vineyards and remained detectable throughout the season. Before insecticide applications, each vineyard was dominated by one of the following phytoseiid species: Kampimodromus aberrans (16 vineyards), Phytoseius finitimus (8), Amblyseius andersoni (4), and Typhlodromus pyri (2). Their response to insecticide applications differed among sites and species. Kampimodromus aberrans densities increased markedly in early summer, peaked in mid-summer, and then declined toward late summer. After pesticide applications, K. aberrans densities were often similar to or higher than pre-treatment levels, with moderate reductions observed in a few cases. Phytoseius finitimus showed relatively high abundance early in the season and generally decreased as the season progressed. After pesticide treatments, its densities commonly declined sharply, except in two vineyards where subsequent densities were higher. Populations of A. andersoni showed variable changes after insecticide applications. Densities often decreased after treatments, although partial recovery was observed in some sites. Typhlodromus pyri showed good density in the spring and early summer, followed by a sharp decrease after insecticide applications, after which it was replaced by A. andersoni. These patterns emphasize species-specific and possibly strain-specific tolerance to insecticides and highlight the importance of community composition when evaluating pesticide compatibility with biological control.
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