Scaphoideus titanus is the main vector of phytoplasmas associated with Flavescence dorée (FD), one of the most serious threats to viticulture in many European countries. To minimize the spread of this disease, mandatory control measures against S. titanus were decided in Europe. In the 1990s, the repeated application of insecticides (mainly organophosphates) proved to be an effective measure to control the vector and the related disease in north-eastern Italy. These insecticides and most of the neonicotinoids were recently banned from European viticulture. Serious FD issues detected in the recent years in northern Italy could be related to the use of less effective insecticides. Trials aimed at evaluating the efficacy of the most used conventional and organic insecticides in the control of S. titanus have been performed in semi-field and field conditions to test this hypothesis. In efficacy trials, carried out in four vineyards, etofenprox and deltamethrin proved to be the best conventional insecticides, while pyrethrins were the most impactful among organic insecticides. Insecticide residual activity was evaluated in semi-field and field conditions. Acrinathrin showed the most significant residual effects in both conditions. In semi-field trials, most of the pyrethroids were associated with good results in terms of residual activity. However, these effects declined in field conditions, probably due to high temperatures. Organic insecticides showed poor results in terms of residual efficacy. Implications of these results in the context of Integrated Pest Management in conventional and organic viticulture are discussed.

Outbreaks of the Nearctic leafhopper Erasmoneura vulnerata represent a threat to vinegrowers in Southern Europe, in particular in North-eastern Italy. The pest outbreaks are frequent in organic vineyards because insecticides labeled for organic viticulture show limited effectiveness towards leafhoppers. On the other hand, the naturally occurring predators and parasitoids of E. vulnerata in vineyards are often not able to keep leafhopper densities at acceptable levels for vine-growers. In this study, we evaluated the potential of two generalist, commercially available predators, Chrysoperla carnea and Orius majusculus, in suppressing E. vulnerata. Laboratory and semi-field experiments were carried out to evaluate both species’ predation capacity on E. vulnerata nymphs. The experiments were conducted on grapevine leaves inside Petri dishes (laboratory) and on potted and caged grapevines (semi-field); in both experiments, the leaves or potted plants were infested with E. vulnerata nymphs prior to predator releases. Both predator species exhibited a remarkable voracity and significantly reduced leafhopper densities in laboratory and semi-field experiments. Therefore, field studies were carried out over two growing seasons in two vineyards. We released 4 O. majusculus adults and 30 C. carnea larvae per m² of canopy. Predator releases in vineyards reduced leafhopper densities by about 30% compared to the control plots. Results obtained in this study showed that the two predators have a potential to suppress the pest density, but more research is required to define appropriate predator–prey release ratios and release timing. Studies on intraguild interactions and competition with naturally occurring predators are also suggested.

Flavescence dorée is a quarantine disease belonging to Grapevine Yellows and affecting European vineyards. It is associated with a phytoplasma primarily transmitted by Scaphoideus titanus Ball (Hemiptera: Cicadellidae) but possibly involving other vectors like Orientus ishidae (Matsumura) (Hemiptera: Cicadellidae). Flavescence dorée-phytoplasma can be transmitted by vectors developed in vineyards and/or by vectors colonizing vineyards from outside (eg neglected vineyards, American vines growing in hedgerows or woody vegetation as well as broad-leaf species occurring at vineyard margins). The role of American vines (derived from Vitis spp. and commonly used as rootstocks) as a source of infective S. titanus is known. In contrast, the risk from broad-leaf trees hosting both O. ishidae and Flavescence dorée phytoplasma remains debated. The potential contribution of woody vegetation as a source of S. titanus and O. ishidae was studied in the 2021 and 2022 growing seasons in a vine-growing area of north-eastern Italy involved in serious Flavescence dorée outbreaks. Four vineyards adjacent to woody vegetation were examined. Results showed that the spatial distribution of S. titanus was more influenced by neighboring vineyards with high vector populations than by adjacent woody vegetation. In many cases, O. ishidae specimens were common along the borders of vineyards adjacent to woody vegetation. The spatial distributions of S. titanus nymphs and adults were related in the same growing season, and this pattern was confirmed considering adults in 2021 and nymphs in 2022. Additionally, the spatial distribution of Grapevine Yellows-symptomatic vines in 2022 was related to the presence of S. titanus but not to that of O. ishidae. Therefore, in the vine-growing area studied, Flavescence dorée outbreaks did not appear to be influenced by the surrounding vegetation or the colonization of O. ishidae.

Predatory mite communities in European vineyards are dominated by the species belonging to the Phytoseiidae family. Surveys on these mites were carried out in several Italian regions in the 1980s when insecticides were seldom used against berry moths. Flavescence dorée (FD) epidemics in northeastern Italy (first in Veneto region) in the 1990s necessitated insecticide applications against the leafhopper Scaphoideus titanus, the main vector of FD-associated phytoplasma. Investigations showed that the increase in organophosphate use has not caused a clear decline in predatory mite populations. Recently, new FD epidemics were detected in North-eastern Italy and pyrethroids were selected for the control of vectors. Their low selectivity towards predatory mites suggested a reappraisal of this topic. Records on Phytoseiidae collected in vineyards in the Veneto region and identified at the University of Padova in 1983 and 2025 were compared. Additional data from definite viticultural areas (i.e., the Conegliano Valdobbiadene Consortium territory) regarding phytoseiid mites collected in 1993 and 2025 were also compared. The survey carried out at regional level in 1983 showed that the most common species were Amblyseius andersoni (39.4% of vineyards), Kampimodromus aberrans (24.2%) and Typhlodromus pyri(15.2%). Euseius finlandicus was also found (15.2%) but only in vineyards not treated with insecticides. The survey conducted in 2025 revealed a clear dominance of K. aberrans (accounted for 56.8% of total individuals and recorded in 56.3% of vineyards), followed by A. andersoni(24.2% and 62.7%, respectively) and Phytoseius finitimus Ribaga (15.4% and 27.8%, respectively). Typhlodromus pyri was rarely detected (0.67% and 0.63%, respectively). The survey conducted in the Conegliano Valdobbiadene Consortium area, in 1993, showed that T. pyri was the most frequent species (75% of vineyards) followed by Paraseiulus talbii (29%) and K. aberrans (28%). However T. pyri was dominant in the 65% of vineyards while K. aberrans and T. talbii in 18% and 2% of them. Phytoseiid assemblage in 2025 was markedly dominated by K. aberrans (85.34% of individuals; 87.5% of vineyards), whereas A. andersoni ranked second but at substantially lower abundance and occurrence (11.46% and 37.5%, respectively). Typhlodromus pyri was present in only one vineyard in this survey (3.16% and 2.5%, respectively). The findings suggest substantial changes in phytoseiid communities over the past 40 years, likely due to climate change and, to a lesser extent, insecticide use.

Outbreaks of the Nearctic leafhopper Erasmoneura vulnerata represent a recent issue for winegrowers in Southern Europe, in particular in North-eastern Italy. Problems are frequent in organic vineyards because insecticides labeled for organic viticulture show limited effectiveness towards leafhoppers. On the other hand, the response by naturally occurring predators and parasitoids to E. vulnerata populations in vineyards is often unable to keep leafhopper densities under levels that are acceptable for winegrowers. Here we evaluated the potential of two generalist predators, i.e., Chrysoperla carnea and Orius majusculus, in controlling E. vulnerata populations. Laboratory and semi-field experiments were carried out to evaluate both species' predation capacity on E. vulnerata nymphs. Then, predators were released in vineyards colonized by large E. vulnerata populations. Both predator species exhibited a remarkable voracity in the laboratory and significantly reduced leafhopper densities in semi-field experiments. Predator releases in vineyards reduced leafhopper densities by about 30%. Results obtained in laboratory, semi-field, and field experiments are discussed to implement these biocontrol agents' use in pest control tactics.