In a vineyard of Central Italy surrounded by two hedges, one composed of bramble, Rubus ulmifolius Schott, and one of elm, Ulmus minor Miller, the green grape leafhopper, Empoasca vitis (Göthe), and the Italian grape leafhopper, Zygina rhamni Ferrari (Homoptera Cicadellidae), did not reach economically important population levels. Although E. vitis and Z. rhamni were found on bramble, this plant is not a major source of colonising grape leafhoppers. Rather it hosts three non-pest leafhoppers: Ribautiana tenerrima (Herrich-Schäffer), Arboridia parvula (Boheman) (Homoptera Cicadellidae), and a species of the genus Zygina. Mainly R. tenerrima serves as an early season food source to parasitoids of the Anagrus complex (Hymenoptera Mymaridae), the most important natural enemies of grape leafhoppers in Italy. This enabled the parasitoid wasps to build up their populations to later colonise the adjacent vineyard. We documented a clear movement of Anagrus from the bramble hedge to vineyard. Anagrus did not exhibit a spring peak on elm, although this plant contributed to continued survival of parasitoids throughout the season by harbouring several leafhopper species: E. vitis, Z. rhamni, A. parvula, Ribautiana ulmi (L.) and a species of the genus Alebra.

Export Date: 27 January 2011Source: Scopus