Ennomos fuscantaria
In 3 days ~20% in a week ~40%
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 London on a given day, based on 123 verified sightings from GBIF citizen-science data. It is the 291st most-seen of the 1504 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
August and September
In those months about 20% of wildlife watchers report a Dusky Thorn in London 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.
2nd of 7
Of the 7 cities where we can rate Dusky Thorn sightings, London ranks 2nd at about 10%. The best odds are in Liverpool (United Kingdom, about 20%).
Same genus: Ennomos
The closest relatives of the Dusky Thorn that you can see in London (genus Ennomos) are August Thorn (about 10%), Canary-Shouldered Thorn (about 10%) 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 London (123 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.
