Coengarion hastulatum is a rare species that suffered a strong decline during the past century. Formerly its distribution included most of the Pleistocene areas. It only occurs in mesotrophic lakes with a rich vegetation including narrow-leafed Carex species, usually Carex rostrata. Changing water management, acidification and eutrophication has caused the species’ disappearance from most of The Netherlands. Fewer than twenty populations remain, most of which are found in the province of Noord-Brabant. The species is classified as critical in the Dutch Red list, and there is no reason to assume that its decline has halted.
Ketelaar, R., Heeffer, J.
- Nederlandse Vereniging voor Libellenstudie 2002. De Nederlandse libellen (Odonata). Nederlandse Fauna 4: 1-440. Nationaal Natuurhistorisch Museum Naturalis, KNNV Uitgeverij & European Invertebrate Survey-Nederland, Leiden.