Ceriagrion tenellum

In the south of its range, C. tenellum is mainly found at seepages, streams, small rivers and standing waters with a rich aquatic vegetation. Further north, in the west and east of France, northern Belgium, the Netherlands, Germany and Great Britain, the species is mainly found in acidic Sphagnum peat bogs and heaths. In this area, it has proliferated since 2000 and is now increasingly found in other types of habitats such as small streams.

Many of the micro-habitats where the larvae are found have the following factors in common: the water temperature can rise quickly in summer and teh dense vegetation, the acidity and/or a low water table limit predation by other dragonflies or fish. The species mainly occurs at lower altitudes and is not found above 1000 m.

Widespread in the western Mediterranean basin, the range spreading into north-west Europe . To the north it reaches the south of Great Britain, the Netherlands and northern Germany. It is widespread in Italy but becomes rare east of the Adriatic sea in the western balkan. Occurence on mainland Greece and Lesbos is uncertain (published records may have been C. georgifreyi). It is found with certainty on Crete and Ios.