Hemistola chrysoprasaria
In 3 days ~10% in a week ~20%
Hemistola chrysoprasaria, the small emerald, is a moth of the family Geometridae. The species can be found in all Europe including the Iberian Peninsula and Russia East to the Ural Mountains, North Africa, Asia Minor, Transcaucasia and the mountains of Eastern Asia (Russian Far East, Siberia), (Amur, Ussuri) and China Tian Shan (as form lissas) Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany | |
| 3 | Pyrénées National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | London | 🇬🇧 United Kingdom | |
| 2 | Vienna | 🇦🇹 Austria | |
| 3 | Copenhagen | 🇩🇰 Denmark |
Rare
Under 5% of wildlife watchers report a Small Emerald sighting in Vienna on a given day, based on 21 verified sightings from GBIF citizen-science data. It is the 575th most-seen of the 1406 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
June and August
In those months about 10% of wildlife watchers report a Small Emerald in Vienna on a given day, against under 5% in July and September–May, the lowest months. Those are among Vienna's wettest months, with about 90 mm of rain a month against 40 mm in February.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Small Emerald sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
2nd of 3
Of the 3 cities where we can rate Small Emerald sightings, Vienna ranks 2nd at under 5%. The best odds are in London (United Kingdom, about 10%).
Same family: Geometridae
The closest relatives of the Small Emerald that you can see in Vienna (family Geometridae, Geometer Moths) are Mottled Umber (about 20%), Small Dusty Wave (about 10%) and Willow Beauty (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Small Emerald is recorded against all the insects logged in Vienna (21 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.
