Sex-Dispersal Differences of Four Phloem-Feeding Vectors and Their Relationship to Wild-Plant Abundance in Vineyard Agroecosystems

Sex-dispersal differences of four phloem-feeding vectors and their relationship to wild-plant abundance were analyzed over 2 yr in two vineyard agroecosystems. Adults of Euscelis lineolatus Brulle` , Neoaliturus fenestratus (HerrichÐScha¨ffer), Psammotettix alienus (Dahlbom), and Hyalesthes obsoletus Signoret were sampled by using yellow sticky traps at two heights (20 and 150 cm) above the ground in a regular geo-referenced grid. Wild vegetation was surveyed around each sampling point. The most abundant species collected was N. fenestratus, followed by P. alienus, H. obsoletus, and E. lineolatus. Low traps were more effective in capturing the females of N. fenestratus and P. alienus and the males of all of the species, except N. fenestratus at one site. Sex ratio was male-biased for N. fenestratus in both agroecosystems at both trap heights, and only in low traps for H. obsoletus and P. alienus at one site. Insect abundance, temporal population dynamics, and dispersal patterns showed considerable ßuctuations according to vineyard agroecosystems and years. In the current study, all of the four phloem-feeding vectors were not found homogeneously in the vineyards, and they were aggregated in correspondence with their herbaceous wild-plant hosts. Insects tended to disperse from the borders toward the vineyard, or vice versa. Colonizing pattern was strongly affected by border vegetation, fallow Þelds, and vineyard ground-cover vegetation. Different plant communities were identiÞed inside the agroecosystems, and signiÞcant correlations among insect and plant-species abundances were recorded. Data highlight the importance of understanding the dispersal patterns of vector species for the application of correct integrated pest-management strategies.