ABSTRACT
The Homoptera Auchenorrhyncha found on vine in various viticolous localities of Italy were listed and divided into normally ampelophagous, occasionally ampelophagous, and erratic species. The most important or significant ones from the phytopathological point of view were examined in relation to the nature of their feeding punctures and divided into mesophyll, phloem, and xylem suckers. The phloem sucker Stictocephala bisonia and the xylem sucker Cicadella viridis were considered also for cauline damages caused by their egg-laying wounds. Among the phloem suckers, both the normally ampelophagous Empoasca vitis, which is very common in some parts of Italy, and Jacobiasca libyca, which is well represented and noxious only in some southern localities of Sardinia, were responsible of remarkable foliar disorders similar to the ones due to other causes, such as pathogenic agents. The typical phloem sucker Scaphoideus titanus, which is an obligatorily ampelophagous species spread over northern Italy, was not found responsible of foliar alterations caused by its feeding punctures. The results of the investigations carried out in Italian vineyards, where it was accused to be vector of the Flavescence dorée MLO, induce to increase the researches on pathogenic agents the transmission of which occurs through graft. About vectors of pathogenic agents, such as viruses and mycoplasma, it seems correct not to neglect investigations on erratic phloem feeding species, e.g. Euscelidius variegatus, Euscelis incisus, Hyalestes obsoletus, Laodelphax striatellus.
