THE STRAWBERRY CROP IN ITALY
From an FAO estimate made in 1996, about 26% of the world production of strawberries, Fragaria × ananassa (Duchesne), is grown in Europe and mostly in Spain and Italy, with about 380 000 tonnes of product per annum (Sbrighi et al., 1998). In the Mediterranean area, strawberries are cultivated both in the open field and in greenhouses (mainly plastic tunnels) with a spring and summer production period.
In Italy, the phytosanitary condition of the strawberry crop varies greatly with latitude and in the warmer areas a wider range of problems commonly occur, for example a hot and dry climate is favourable to the development of pests such as the red spider mite, Tetranychus urticae Koch. For instance outbreaks of western flower thrips (WFT), Frankliniella occidentalis (Perg.), are usually higher and cause more severe outbreaks in southern regions than in northern ones. WFT can overwinter in quiescence mainly when plastic covers are set up in the autumn or early winter (Tommasini & Maini, 1995). On the other hand, aphids can be particularly harmful in temperate regions such as in northern Italy. Towards central and southern Italy aphids become less of a problem (Nicoli, 1992). The more frequent aphid species on strawberry in Italy are Macrosiphum euphorbiae (Thom.) and Chaetosiphon fragaefolii (Cock.) (Benuzzi et al., 1991b), with occasional problems with Aphis gossypii Glov. and Myzus persicae (Sulz.) (Galazzi & Nicoli, 1992). Also growing techniques can influence plant development and the damage caused by some arthropod pests or diseases. The main pests occurring on strawberry in the Mediterranean area, especially in Italy, are summarised in Table 26.1.