De terugkeer van de Rivierrombout (Gomphus flavipes (Charpentier)) in Nederland

Until a few years ago Gomphus flavipes was thought to be extinct in the Netherlands. The last records dated from 1902. The discovery of a larva of this species in the cooling-water filters of a powerstation in 1996 indicated that Gomphus flavipes might have returned to the Netherlands. In 1998 more larvae were found at the powerstation and several fieldtrips were undertaken to confirm the return of the species. At eight localities along the river Waal (lower course of the Rhine) near Nijmegen in the eastern part of the Netherlands, teneral adults and/or exuviae were found. This proves that G. flavipes has returned as a breeding species in the Dutch riversystem. The recent return of Gomphus flavipes corresponds with the expansion in Germany. The causes of the expansion are not clear. In search for G. flavipes along the river Waal, several exuviae of G. vulgatissimus were found as well. This species had also not been recorded in large Dutch rivers for a long time.