The effect of cover plants on arthropod functional biodiversity was investigated in a vineyard in Northern Italy, through a 3-year field experiment. The following six ground cover plants were tested: Sweet Alyssum; Phacelia; Buckwheat; Faba Bean; Vetch and Oat; control. Arthropods were sampled using different techniques, including collection of leaves, vacuum sampling and sweeping net. Ground cover plant management significantly affected arthropod fauna, including beneficial groups providing ecosystem services like biological control against pests. Many beneficial groups were attracted by ground cover treatments in comparison with control, showing an aggregative numerical response in the plots managed with some of the selected plant species. Alyssum, Buckwheat and 'Vetch and Oat' mixture showed attractiveness on some Hymenoptera parasitoid families, which represented 72.3% of the insects collected by sweeping net and 45.7 by vacuum sampling. Phytoseiidae mites showed a significant increase on leaves of the vineyard plots managed with ground covers, in comparison with control, although they did not show any difference among the treatments. In general, the tested ground cover treatments did not increase dangerous Homoptera populations in comparison with control, with the exception of Alyssum. The potential of ground cover plant management in Italian vineyards is discussed: the overall lack of potential negative effects of the plants tested, combined with an aggregative numerical response for many beneficials, seems to show a potential for their use in Northern Italy vineyards.

The phytoplasmas associated with bois noir (BN) tuf-type a are transmitted to grapevines by means of Hyalesthes obsoletus Signoret using Urtica dioica L. as the inoculum source. In the period 2003–2008, a research was carried out in six vineyards of northern Italy where a large amount of nettles in the ditches surrounding vineyards was detected. The aim was to establish the nettle control effects on the presence of H. obsoletus and new symptomatic grapevines. PCR and RFLP analyses showed the presence of the BN tuf-type a phytoplasmas in symptomatic grapevines of all vineyards and in the vector. Weed control strategies along ditches were always associated with decreases in nettle coverage and H. obsoletus numbers. A reduction in the percentage of new symptomatic grapevines occurred in all vineyards except for one vineyard where the least reduction in nettle and H. obsoletus was observed. The decrease in H. obsoletus population was significantly correlated with a decrease in nettles along ditches, and the reduction in H. obsoletus population was correlated with a decrease in incidence of new symptomatic grapevines compared with the incidence before the application of weed control measures. Nettle weeding can reduce the incidence of BN tuf-type a, but weed control costs and impacts need to be considered

Stinging nettle (Urtica dioica L.) is the most important host plant for both phytoplasma associated with Bois noir disease of the grapevine and its vector Hyalesthes obsoletus Signoret (Hemiptera: Cixiidae). Vector abundance in vineyards is favored by stinging nettle growing in surrounding areas. Nettle control by herbicides or cutting can reduce vector population in vineyards. However, chemical weeding can cause environmental problems. Many authors suggest that stinging nettle control applied during H. obsoletus flight could force adults to migrate into vineyards. We evaluate if cutting of nettle growing along ditches during adult flight favors vineyard colonization by H. obsoletus. Three different weed management regimes ("no cuts," "one cut" just before the beginning of adult flight, and "frequent cuts" over the whole vegetative season) were applied to the herbaceous vegetation in ditches bordering two vineyards. The flight dynamics of H. obsoletus were recorded by placing yellow sticky traps on the vegetation along the ditches and at different positions in the vineyards. Frequent stinging nettle cuts (compared with a single cut) in surrounding areas favored the dispersion of vectors inside the vineyards. Stinging nettle control should be based on an integration of a single herbicide application before H. obsoletus emergence followed by frequent cuts to minimize negative side effects of chemical weeding. In organic viticulture, a frequent-cuts strategy should avoid cuts during H. obsoletus flight period, at least in the first year of adoption.

A severe outbreak of European Stone Fruit Yellows (ESFY) has been reported recently in apricot (Prunus armeniaca) orchards located in the province of Trento (Italy), where partial or total tree dieback caused major economic losses to growers. In order to prevent the disease spreading, the presence of ESFYP-vector, the psyllid Cacopsylla pruni, was monitored together with wild reservoirs of the phytoplasma. Five experimental orchards were planted using ESFYP-free material (cv. Bergeron and Goldrich grafted on "Wavit" or "Myrobolan 29C") to perform epidemiological studies. A multiplex real-time PCR procedure (TaqMan) was set up using two primers/probe combinations for simultaneous detection of ESFYP and host DNA, in order to avoid false negatives due to PCR inhibition. Real-time PCR assays were performed on: propagation material, groups of C. pruni (2 insects per group) and wild individuals of several Prunus spp. collected in areas close to the experimental orchards and individual samples from apricots showing ESFYP-like symptoms. The results obtained indicate that the primers/probe combination used in the real-time PCR procedure allows reliable and specific detection of ESFYP. The pathogen was detected in 93% of the apricot trees showing ESFYP-symptoms and in ~ 33% of the insect groups and in several wild species collected in different locations. No phytoplasmas were found in healthy plants or in propagation material. This result suggests that new infection of trees is presumably due to ESFYP transmission by vectors rather than by contamination of propagation material. Further research is in progress to check the presence of ESFYP-sources in wild plants close to experimental orchards and to monitor pathogen's dissemination. * including: 20 asymptomatic plants collected in the orchards, 203 samples from propagation material and 10 healthy apricots.

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