Chalcolestes viridis
In 3 days ~10% in a week ~30%
Chalcolestes viridis, formerly Lestes viridis, is a damselfly of the family Lestidae. It has a metallic green body and at rest it holds its wings away from its body. Its common name is the willow emerald damselfly, the green emerald damselfly, or the western willow spreadwing. It has an elongated abdomen and pale brown spots on its wings and resides in areas of still water with overhanging trees.
The genus Chalcolestes is separated from Lestes because of differences in their larvae. A closely related species C. parvidens used to be considered a sub-species of C. viridis. C. parvidens occurs in Greece, Bulgaria, Croatia and in Italy; near Rome it flies with C. viridis in the same ponds. There are small morphological differences between the two species both as adults and larvae and analysis of proteins from the two species, by electrophoresis, also supports their separation into two species, but they are hard to tell apart in the field. C. parvidens flies earlier in the year than C. viridis.
C. viridis is found across southern and central Europe and in North Africa. In the eastern mediterranean it is replaced by C. parvidens with areas of... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 3 | Wadden Sea National Park | 🇩🇪 Germany | |
| 4 | Sierra de Guadarrama National Park | 🇪🇸 Spain |
Rare
Under 5% of wildlife watchers report a Western Willow Spreadwing sighting in Prague on a given day, based on 19 verified sightings from GBIF citizen-science data. It is the 316th most-seen of the 724 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
August to October
In those months about 10% of wildlife watchers report a Western Willow Spreadwing in Prague on a given day, against under 5% in November to July, the lowest months.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Western Willow Spreadwing sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
20th of 21
Of the 21 cities where we can rate Western Willow Spreadwing sightings, Prague ranks 20th at under 5%. The best odds are in Brussels (Belgium, about 30%), Rotterdam [The Hague] (Netherlands, about 20%) and London (United Kingdom, about 20%).
GBIF citizen-science records
It is estimated from how often the Western Willow Spreadwing is recorded against all the insects logged in Prague (19 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
