Since 2008, Drosophila suzukii, the spotted wing drosophila, has colonized most of the American and European continents, being able to adapt to very different climates. In Italy, this pest has been captured from northern Alpine to southern Mediterranean regions where it can infest a broad range of fruits, including wine grapes. Studies have shown that oviposition levels and developmental rates of D. suzukii on wine grapes are lower than on other berries, although recent observations indicate that grapes may become a suitable host plant in particular conditions. Here, we report, for the first time, the results of a series of no-choice oviposition experiments using berries of five table grape varieties sampled in the provinces of Taranto and Bari (Apulia region, south-eastern Italy) during 2013 from both organic and conventional farming systems.The sugar content (SC) and skin hardness of each sample were analysed to assess the influence of these physiological parameters on the susceptibility of table grapes to D. suzukii infestation. A negative correlation was found between the number of eggs laid and berry skin penetration force, whereas there was a positive one between the number of eggs and Brix values, as well as sampling date. In organic grapes, SC and skin hardness of two varieties ("Crimson" and "Scarlotta") were measured, respectively, higher and lower than in conventional grapes, thus making them more susceptible to pest infestation. The study hence shows that in laboratory conditions D. suzukii is able to heavily infest and develop on table grapes and that susceptibility to its infestation significantly depends on both variety and farming system. K E Y W O R D Salien invasive pests, conventional and organic farming, fruit flies, pest control

Introduction. Drosophila suzukii Matsumura (Spotted Wing Drosophila, SWD) is a pest that has been indicated as a major threat to European and Mediterranean fruit production. Its finding in Southern Italy offers interesting data to elaborate an efficient and sustainable control strategy. Materials and methods. The fly was collected during the "overhead" survey of an IAMB organic table grape vineyard by apple vinegar/wine/brown sugar bottle traps placed in and around the field. Once the presence of this pest was confirmed, traps were also hung on different host plants surrounding the vineyard, namely fig (Ficus carica L.), jujube (Ziziphus jujuba Mill.), pomegranate (Punica granatum L.), wild bramble (Rubus fruticosus L.) and rough bindweed (Smilax aspera L.). Collected Drosophila adults were identified via morphological parameters by comparison with published descriptions and drawings. The SWD adult population was monitored per month throughout the year and related to the average values of the temperature (• C) and minimum relative humidity (mRH%). The survey was carried out from September 2012 to August 2013. Results and discussion. We report the finding of Drosophila suzukii in Southern Italy, Apulia Region, and its population dynamics throughout the year in the area. In addition to D. suzukii, D. melanogaster (Meigen), D. simulans (Sturtevant) and similar species were also scored. The D. suzukii dynamics appeared to be strictly correlated with the temperature and relative humidity changes throughout the year, with a great summer population decrease. This behaviour is quite different from that of other indigenous drosophilas, both pest and non-pest. Conclusion. D. suzukii has, at present, a prominent pest status and may represent a key pest of soft fruit orchards in the SouthEastern part of Italy and, namely, in Apulia. However, further investigation on the marked decrease in the SWD summer population is needed to support effective pest control strategies, which include baited-lure mass trapping in Mediterranean and other warm climate areas. Such strategies should also take into consideration pest reservoirs such as secondary and semi-wild fruit species bred in the areas tested.