Polia nebulosa
In 3 days ~10% in a week ~20%
Polia nebulosa, the grey arches, is a moth of the family Noctuidae. The species was first described by Johann Siegfried Hufnagel in 1766. It is found in temperate Europe and Asia up to eastern Asia and Japan. It is not present in northernmost Fennoscandia and the southern parts of the Iberian Peninsula, Italy and Greece. In the Alps it is found at heights up to 1,600 meters.
The wingspan is 41–52 mm. Forewing white tinged with brownish grey; stigmata as in Polia advena and Polia tincta; submarginal line preceded by black wedge-shaped marks, with one more conspicuous before the indentation of submedian fold; hindwing dull whitish, with, cellspot, veins, and a broad marginal border smoky fuscous; — ab. pallida Tutt represents a very white form taken in Scotland, with many of the dark transverse markings obsolete; — bimaculosa Esp. is the darker grey form with blacker markings; — robsoni Collins is a strong melanic form from Cheshire in the west of England only; there are also two aberrations from East Asia, — asiatica Stgr. (= lama Stgr.) being dull grey and smaller than typical, while askolda Oberth. from Askold Island [now ssp.] is a large... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Bavarian Forest National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Nizhny Novgorod | 🇷🇺 Russia | |
| 2 | Kyiv | 🇺🇦 Ukraine | |
| 3 | London | 🇬🇧 United Kingdom | |
| 4 | Moscow | 🇷🇺 Russia |
Rare
Under 5% of wildlife watchers report a Grey Arches sighting in Nizhny Novgorod on a given day, based on 9 verified sightings from GBIF citizen-science data. It is the 293rd most-seen of the 405 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, September and November
In those months about 10% of wildlife watchers report a Grey Arches in Nizhny Novgorod on a given day, against under 5% in July–August, October and December–May, the lowest months.
Between midnight and 3 am
Across all the parks we cover, that three-hour window holds the most Grey Arches sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is seen both by day and at night.
Yes
Of the 4 cities where we can rate Grey Arches sightings, Nizhny Novgorod has the highest daily chance: under 5%. Next come Kyiv (Ukraine, under 5%) and London (United Kingdom, under 5%).
Same family: Noctuidae
The closest relatives of the Grey Arches that you can see in Nizhny Novgorod (family Noctuidae, Cutworm Moths and Allies) are Knot Grass Moth (about 10%), Heart And Dart (about 10%) and Silver Υ (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Grey Arches is recorded against all the insects logged in Nizhny Novgorod (9 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.
