The blue damselfly (Calopteryx virgo) is, together with the banded damselfly, the largest of the damselflies living here. From head to the end of the abdomen it is 45 to 50 mm long, and the wingspan measures about 6 cm. The male can be immediately and reliably identified by its coloration, as the entire animal is blue. Usually the entire surface of its wings is cobalt blue, and its metallic blue thorax blends into metallic green.
The female's body is metallic green in color, and for this reason it is often difficult to distinguish it from the females of the related banded damselfly. Unlike the aforementioned species, the female of the blue damselfly has wings that are more or less entirely brownish.
The blue damselfly also courts the female before mating with fluttering and displaying the blueness of its appearance, which among damselflies, known as rough suitors, is a true rarity. It also behaves like a gentleman and does not engage in fierce physical clashes with rivals, but defends its territory solely with ritual wing displays.
The blue damselfly is a resident of clean, oxygen-rich waterways with dense shoreline vegetation, which provides more shade. A typical habitat of this species is natural forest streams, where they occur from May to late September.
