Walnut (Juglans regia L.) is traditionally present in most European countries as an ornamental tree, and in Southern Europe in particular it is grown for both fruit and wood. Since the 1980s, to supply the increasing demand for walnut timber, large areas of southern and central Europe, from France to Hungary, have been planted with black walnut (Juglans nigra L.) to provide wood for furniture production. The fungus Geosmithia morbida and its vector Pityophthorus juglandis, causing the thousand cankers disease of walnut in the USA in the last 2 decades, were recently reported in Europe (in Italy) on both walnut species. Thousand cankers disease can have a high negative impact on the landscape and economy of many agricultural and forest areas. Following a detailed pest risk analysis performed by EPPO in 2015, both organisms were included in the EPPO A2 List of pests recommended for regulation as quarantine pests. The main biological, epidemiological and monitoring aspects of thousand cankers disease and its status in Europe are reported.

This paper presents 3 years of GIS‐based monitoring of western corn rootworm (WCR –Diabrotica virgifera virgifera LeConte), a pest which invaded Northern Italy in 1998. The Veneto Region established a regional monitoring network to detect this important quarantine pest and to employ an eradication programme. Data were collected by means of sex pheromone PAL traps and analysed by Indicator Kriging, a geostatistics tool that determines the probability of data values in a given area being greater than a defined threshold value. Geostatistical analysis proved to be effective in mapping the spread of WCR. The temporal sequence of the probability maps was useful in interpreting the expansion of the insect. The detailed description of the pattern of WCR presence in 2006–2008 proves the temporary and local efficacy of the eradication programme carried out up to the 2006 season in Venezia province. An interpretation of the spatial pattern of WCR between the 2006 and 2008 seasons suggests that the pest colonized the eradication area coming from other invasion fronts. The large‐scale pattern of WCR dispersion can be accurately described by the spatial approach, thus optimizing the monitoring and subsequent control of this important insect pest of Northern Italy. Other data analyses, based on stochastic interpolations and a demographical approach are in progress. An interesting perspective would be to build predictive simulation models based on climatic and agronomic data taking into account the spatial representation of WCR patterns.

In early April 2009, many specimens of Ambrosiodmus (Hopkins, 1915) (Coleoptera: Curculionidae: Scolytinae), a genus new to Europe, were found overwintering in a living horse chestnut tree (Aesculus hippocastanum L.) in the botanic garden of Padova (NE Italy) (45°23’ N, 11° 52’ E). In October 2009, about 80 peach trees growing in an orchard close to Verona (Alpo di Villafranca, NE Italy) (45°22’ N, 10° 55’ E) were found infested by the same insect. In both cases, the insects were infesting the tree sapwood infected by honey fungus (Armillaria mellea (Vahl) Kummer). Moreover, in the first week of October one specimen was collected also in a pheromone trap baited with ipsdienol and ipsenol and set up in the international harbour of Venice (Marghera, 45°27’ N, 12° 15’ E). Subsequent morphological analyses ascribed the collected specimens to the species A. rubricollis (Eichhoff, 1875), an ambrosia beetle of Asian origin. The infested trees were submitted to sanitation felling and burnt. Some infested log was placed in a transparent and ventilated plastic cage, kept under laboratory conditions (21±1 °C, 70% r.h., and L16:D8 photoperiod) waiting for insect emergence. Emerging adults were removed daily, identified and sexed by morphological features. The rearing gave several thousands of adults, with a female:male ratio of about 40:1.

The western corn rootworm (WCR) Diabrotica virgifera virgifera LeConte, is considered a threat in Italian maize cropping systems due to the biological characteristics and the climatic and agronomic conditions favouring its development and establishment. This project describes the measures implemented since 1995 to monitor the potential introduction of WCR into Italy and to prevent the spread from nearby Serbia. The most effective measure was the monitoring program which used sex pheromone traps, produced by the Plant Protection Institute of Budapest in sensitive areas (maize fields near airports, customs areas, tourist facilities, etc.) in Northeastern Italy. This activity allowed for identification of newly and accidentally introduced specimens near the International Airport in Venice in 1998. All strategies, restrictions and obligations, which were implemented in Italy, in order to eradicate or at least to delay Diabrotica WCR dispersal, are discussed.

European beech (Fagus sylvatica) is an important forest tree species common in northern and central Europe. In Italy, this species is typical in mountain areas over 1,000 m above sea level. In the last decade, decline and death was reported on European beech caused by several Phytophthora species (2), and P. pseudosyringae was recently reported in Italy (3). During 2004 and 2005, seven declining and dying F. sylvatica trees, older than 20 years, were observed in the Veneto Region of Italy with symptoms of bleeding cankers at the base of trunks and on branches. Cankers on the collar showed tongue-shaped necroses of the inner bark and cambium tissues. Four trees were in a public park of Mestre and three were in a forest stand in the province of Belluno. Samples were taken from declining trees, one in the park and two in the forest. Inner bark and cambium tissue pieces were cut from the canker margins, cultured on CARPBHy-agar (corn meal agar amended with 250 μg ml-1 ampicillin, 10 μg ml-1 rifampicin, 10 μg ml-1 pimaricin, 15 μg ml-1 benomyl, 50 μg ml-1 hymexazol), and incubated at 20°C. Ten morphologically similar isolates were subcultured as single hyphal tips and characterized. These isolates produced nonpapillate sporangia that were ovoid, obpyriform or ellipsoid, and exhibited predominately internal proliferation in soil extract. Hyphal swellings with outgrowths were present under those conditions. The morphological characteristics were consistent with those of P. cambivora (1). Base sequences of the ITS region of rDNA were determined for six of the isolates, and an 832-bp fragment was amplified for each isolate and that sequence was 100% homologous with sequences DQ396418 and AY880985 of P. cambivora in the NCBI database ( http://www.ncbi.nlm.nih.gov/BLAST/ ). The sequence of one isolate, ISPaVe 1950, was deposited in GenBank (Accession No. AM269752). Pathogenicity tests were conducted with 2-year-old potted beech seedlings. Inoculum of representative isolates was grown for 4 weeks on sterilized millet seeds moistened with V8 broth and added to soil at 3% (wt/vol). Control plants received sterilized inoculum only. The soil was flooded for 48 h. Inoculations were performed during May 2005 at 15 to 35°C with six replicates for the inoculated and control plants. The plants were maintained outdoors and assessed after 3 months. Wilt, root rot, and dark brown lesions at the collar developed on inoculated plants, but not on the controls. Symptoms were similar to those on naturally infected trees. The pathogen reisolated from the inoculated plants was morphologically identical to the original isolates, which confirmed P. cambivora as the causal agent. To our knowledge, this is the first report of P. cambivora on beech in Italy. References: (1) D. C. Erwin and O. K. Ribeiro. Phytophthora Diseases Worldwide. The American Phytopathological Society, St. Paul, MN, 1996. (2) T. Jung et al. Mycologist, 19:159, 2005. (3) E. Motta et al. Plant Dis. 87:1005, 2003.