Population dynamics and dispersal of Scaphoideus titanus from recently recorded infested areas in central-eastern Italy

We investigated the presence of the leafhopper Scaphoideus titanus Ball in the Marche region, central Italy, during a 10-year survey. Furthermore, from 2009 to 2011, yellow sticky traps were deployed to investigate the population dynamics. Taylor's power law and distance-weighted least-squares contour maps were used to determine the leafhopper distribution within vine fields. Polymerase chain reaction was used to detect Flavescence doreé (FD) phytoplasma in insect bodies. The leafhopper was first recorded in 2007 in a commercial nursery of scion mother vines (1 specimen) in southern Pesaro-Urbino province and in 2009 in a commercial vineyard (1 specimen; the FD focus) in north-eastern Pesaro-Urbino. Adults (total, 301) were recorded from end of June to end of September, 2009-2011, with a shifted flight activity observed for females. Male captures were more abundant than females (M:F = 1.71; p < 0.001). In the site including the FD focus, insecticide treatments contributed to very low leafhopper population levels: only a few individuals (n = 4) were caught, and no phytoplasma were detected in their bodies. Comparisons of trapping data indicate significant increase in captures from 2009 to 2011 where correct pest management was not applied. Taylor's power law indicates that adults had an aggregated distribution (R2 = 0.99; b = 1.52; p < 0.001), with high population density in the central part of the vine field. Leafhopper dispersal showed a maximum 600-m radius. We also discuss the pathways of S. titanus introduction into the Marche region, and factors that might have influenced its dispersal.