Ennomos fuscantaria
In 3 days ~30% in a week ~60%
Ennomos fuscantaria, the dusky thorn, is a moth of the family Geometridae. The species can be found in the western part of the Palearctic realm in western Europe and from central Scandinavia its range extends to the northern Mediterranean and east to Russia.
The wingspan is 35–40 mm. The ground colour is ochre yellow. There are violet-grey flecks on the forewing and an oblong discal spot. The fasciae (bands) are grey brown. On the hindwing the grey brown transverse line hides a small discal spot.
Other Ennomos species are similar. The moth is on wing from July to October depending on the location. The caterpillars feed on ash (Fraxinus excelsior), but also privet (Ligustrum species) and other shrubs. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Sierra de Guadarrama National Park | 🇪🇸 Spain | |
| 3 | Bavarian Forest National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Liverpool | 🇬🇧 United Kingdom | |
| 2 | London | 🇬🇧 United Kingdom | |
| 3 | Birmingham | 🇬🇧 United Kingdom | |
| 4 | Manchester | 🇬🇧 United Kingdom | |
| 5 | Leeds | 🇬🇧 United Kingdom | |
| 6 | Essen | 🇩🇪 Germany | |
| 7 | Copenhagen | 🇩🇰 Denmark |
With luck
About 10% of wildlife watchers report a Dusky Thorn sighting in Snowdonia National Park on a given day, based on 18 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 117th most-seen of the 387 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
August and September
In those months about 30% of wildlife watchers report a Dusky Thorn in Snowdonia National Park on a given day, against under 5% in October to June, the lowest months.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Dusky Thorn sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
Yes
Of the 3 parks where we can rate Dusky Thorn sightings, Snowdonia National Park has the highest daily chance: about 10%. Next come Sierra de Guadarrama National Park (Spain, about 10%) and Bavarian Forest National Park (Germany, about 10%).
Same genus: Ennomos
The closest relatives of the Dusky Thorn that you can see in Snowdonia National Park (genus Ennomos) are Canary-Shouldered Thorn (about 20%) and September Thorn (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Dusky Thorn is recorded against all the insects logged in Snowdonia National Park (18 verified sightings from 2019 to 2026), 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.
