Dorsal black being interrupted is the abdominal pattern found on the so-called blue form females of our 2 most widespread Coenagrion species, the Azure Damselfly (Coenagrion puella) and the Variable Damselfly (Coenagrion pulchellum). The Azure damselfly is very widespread and common. The Variable Damselfly has a wide-ranging but patchy distribution.
Separating these terrible twins reliably requires a clear, detailed view of the pronotum.
Azure Damselfly (Coenagrion puella) female pronotum
Variable Damselfly (Coenagrion pulchellum) female pronotum