The white-legged damselfly or blue featherleg (Platycnemis pennipes) is a damselfly of slow-flowing, muddy waters.
It occurs from the Atlantic to Siberia and is often abundant throughout its range.
Morphology
Platycnemis pennipes is about 32 millimetres (1.3 in) long. Mature adults differ from most other blue damselflies in having expanded white edges to the tibiae, paired black markings down most of the abdomen, broad pale brown double antehumeral stripes, wider head and a pale brown pterostigmata.
The male has a blue abdomen that is often pale and usually has a greenish thorax. The female is a very pale yellow-green colour with black markings.
This species favours unshaded slow-flowing sections of muddy rivers with abundant floating vegetation. it has been recorded in tidal rivers and the larvae seem well able to tolerate brackish water. It also occurs in muddy streams but is rare in lakes or ponds of any sort. In north-west Europe, it is mostly confined to flowing waters.
Mating is preceded by the male displaying his white legs in a fluttering display flight in front of females. Elongated eggs are laid whilst in tandem, into emergent stems and especially the underside of floating leaves. The larvae live amongst bottom debris and emerge after two years.
Behaviour
Male sunbathing in the vegetation
After emerging, adults tend to congregate in the shelter of tall vegetation, although some immatures wander away from water and have been found five kilometres away from the nearest breeding site.
Source: Wikipedia
Český popis najdete zde http://www.naturabohemica.cz/platycnemis-pennipes/
Dobrá pražská lokalita na břehu Vltavy v Modřanech.
Good Prague location on the banks of the Vltava River in Modřany.
https://www.inaturalist.org/observations/142371791
Extensive South Bohemian pond area Třeboňsko. There are many dragonflies to be seen around the ponds or the Lužnice and Nežarka rivers.
Rozsáhlá Jihočeská rybniční oblast Třeboňsko. Zde je kolem rybníků nebo řeky Lužnice a Nežárky k vidění mnoho vážek.
https://www.inaturalist.org/observations/127540348
This female is from the forested, hilly terrain near Stříbro, West Bohemia. Perhaps not a typical location.
But it's quite wet in places and there are trickles of water running down to the valley streams.
Tato samice je z lesnatého, kopcovitého terénu u západočeského Stříbra. Možná ne úplně typická lokalita.
Je tu ale místy dost vlhko a do údolí k potůčkům se stékají stružky vody.
https://www.inaturalist.org/observations/120919824
Observations from the lower reaches of the Berounka River between Beroun and Srbsko. This is a much more common habitat.
Pozorování z dolního toku řeky Berounky mezi Berounem a Srbskem. To je mnohem obvyklejší biotop.
https://www.inaturalist.org/observations/96336228
Observation from Jizera river, Central Bohemia region. They should be here.
Pozorování od řeky Jizery, Středočeský kraj. Tady by měly být.
https://www.inaturalist.org/observations/88414868
Here is a sighting also from Berounka but in Křivokládsko above Beroun.
Tady je pozorování též od Berounky ale na Křivokládsku nad Berounem.
https://www.inaturalist.org/observations/95421962