First occurrence of western corn root worm beetles in the federal states Hesse and Rhineland-Palatinate (Germany), 2011

Abstract

In 2011, western corn root worm beetles were detected in the federal states Hesse (Groß-Gerau) and Rhineland-Palatinate (Bodenheim) for the first time. Control measures based on commission decision 2003/766/EG (Byrne, 2003) were conducted after detection in PAL-traps. Focus and safety zones were established. In Hesse, both focus and safety zones were treated with the insecticide Biscaya, due to the high number of 50 beetles which were detected in the PAL-traps. Since in Rhineland-Palatinate, only one beetle had been captured, only the focus zone was treated with the insecticide. After insecticide treatment, new PAL-traps were arranged like a close grid over the infested areas in both federal states. In each maize field in the focus- and safety zone further traps were placed and checked weekly until September 30th by supporting staff. Until the end of the monitoring in 2011 (September 30th) further beetles were detected in the south of the area (district of Groß-Gerau, Hesse), were the first infestation had been discovered. However, in Rhineland-Palatinate no further beetles were detected that year. By the end of the monitoring 354 beetles in Hesse and one beetle in Rhineland-Palatinate had been captured in total. Subsequently the demarked zones in Hesse were extended. Taking into account the local circumstances, the new focus zone was delimited to include all the areas where beetles had been detected as well as the surrounding maize fields. In the focus zones the cultivation of maize was forbidden for the consecutive two years and a crop rotation with at least 50 percent maize was established in the safety zones. In 2012 no further beetles were captured in the infested region.

Keywords

• Diabrotica virgifera virgifera LeConte
• first occurrence
• Hesse
• Rhineland-Palatinate
• eradication