Initial movements of the introduced alien western corn rootworm (Diabrotica virgifera virgifera) for colonising suitable habitats

摘要

In the late 1980s, a new maize pest, western corn rootworm (WCR) (Diabrotica virgifera virgifera), was accidentally introduced from North America into Serbia. Within 10 years, this alien beetle spread rapidly throughout Central Europe. Recently, several new sites of isolated introductions were reported in Europe, such as around Paris (France), Basel (France and Switzerland), Amsterdam (the Netherlands) and London (UK). These multiple introductions raise the question of the process of initial spread of the beetles over unfavourable habitats, with movement towards maize fields being one of the potential key factors behind the invasiveness of WCR. In order to investigate such initial colonisation movements of WCR adults, in southern Hungary in 2003 and2004, mark release/recapture techniques were applied in large steppe and lucerne areas. Preliminary results underline that WCR is a very active flyer, and is able to move actively over long distances; however, no consistent major vectors of directed flight were found. Circular correlations were shown between WCR movement and habitat structures, such as maize and lucerne.