Ewinia stewartii, Hyphantria cunea and Liriomyza trifolii in Italy
Situation for Erwinia stewartii in Northern Italy
According to Mazzucchi, Informatore fitopatologico 1/84, pp. 18-23, the reappearance of E. stewartii in the Po valley in 1982 (cf. EPPO Reporting Service 83/3, n°445) has been followed by a few further cases in 1983. It seems likely that infected seed lots were again to blame, and there is no indication that the bacterium is established in Italy. However, the situation is being watched closely. The use of resistant hybrids or cultivars should be preferred.
Hyphantria cunea in Reggio Emilia
According to Montermini & Oliva, Informatore fitopatologico, 1 /84, pp. 35-40, H. cunea has made massive attacks on ornamental and agricultural trees in a few locations in the province of Reggio Emilia. The preferred hosts are Morus and Acer negundo. The establishment of this species in Italy is confirmed (cf. EPPO Data Sheet n°111).
Liriomyza trifolii in Italy
First reported under glass in Liguria in 1979, L. trifolii has now been found on gerbera and chrysanthemum in Toscana and in Lazio (1980) and under glass in the region of Ragusa in Sicily (1983). Although found to multiply on outdoor marguerite (Chrysanthemum frutescens L.) in summer, the leafminer does not cause any problems in winter although it can survive outdoors in the pupal stage.
Studies on its development in relation to temperature have been made (Informatore fitopatologico, 2/84, pp. 8-12).