Situation of Lissorhoptrus oryzophilus in Italy
The rice water weevil, Lissorhoptrus oryzophilus (Coleoptera: Curculionidae - formerly EPPO Alert List), was first detected in Lombardia, Northern Italy, in 2004 (see EPPO RS 2005/005). This was also the first report of this North American pest in Europe. Studies have recently been carried out in Italy to determine its spread and better understand its biology. Results showed that, as of 2010, L. oryzophilus had invaded the entire rice-growing area in the Piemonte and Lombardia regions. The first detection outside this area was made in 2013 near Ferrara (Emilia-Romagna region) nearly 270 km away from the initial finding site of 2004. In 2014, the pest was also detected near Verona (Veneto region) and in 4 other localities near Ferrara. As rice is not grown continuously between Piemonte/Lombardia and the newly invaded areas, these long range movements might be explained by anthropogenic activities or the presence of many waterways with wild host plants which were able to sustain the development of the pest. It is noted that although L. oryzophilus is showing an invasive behaviour in Italy, economic damage has remained minimal and limited to small areas every year. Finally, these studies also confirmed that in Italy, L. oryzophilus behaves as a monovoltine parthenogenetic species.
Lupi D, Jucker C, Rocco A, Giudici ML, Boattin S, Colombo M (2015) Current status of the rice water weevil Lissorhoptrus oryzophilus in Italy: eleven-year invasion. Bulletin OEPP/EPPO Bulletin 45(1), 123–127.