Xanthorhoe ferrugata
In 3 days ~20% in a week ~40%
Xanthorhoe ferrugata, the dark-barred twin-spot carpet, is a moth of the genus Xanthorhoe in the family Geometridae. It was first described by Carl Alexander Clerck in 1759 and has a Holarctic distribution. It is found in Europe and east to the Russian Far East, Siberia, Tibet and China, south to the Caucasus and Turkey. Also in North America (Alaska to Newfoundland and south to North Carolina and California).
The name-typical form of ferrugata as figured by Clerck and well described by Linné, has the median band reddish or purplish, the distal area very weakly marked (except the costal patch and two dark spots between the radials) often almost entirely white or whitish. An aberration, ab. unidentaria Haw. is a very common and very interesting aberration which has been proved, by my very extensive breeding experiments and those of Dr. Draudt, to be an almost perfect Mendelian "recessive". It differs in having the median band black, not reddish. — ab. coarctata Prout has the median band greatly narrowed, only 1–2 mm. in width; the rest of the markings often in part obsolete. - bilbainensis Fuchs, from Bilbao, said to be a local race, is described... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Pyrénées National Park | 🇫🇷 France | |
| 3 | Wadden Sea National Park | 🇩🇪 Germany | |
| 4 | Bavarian Forest National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Porto | 🇵🇹 Portugal | |
| 2 | Detroit | 🇺🇸 United States | |
| 3 | Helsinki | 🇫🇮 Finland | |
| 4 | Liverpool | 🇬🇧 United Kingdom | |
| 5 | Boston | 🇺🇸 United States | |
| 6 | Edmonton | 🇨🇦 Canada | |
| 7 | Montreal | 🇨🇦 Canada | |
| 8 | Berlin | 🇩🇪 Germany | |
| 9 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 10 | Toronto | 🇨🇦 Canada |
With luck
About 10% of wildlife watchers report a Dark-Barred Twin-Spot Carpet sighting in Detroit on a given day, based on 14 verified sightings from GBIF citizen-science data. It is the 120th most-seen of the 268 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.
April–May and July–August
In those months about 10% of wildlife watchers report a Dark-Barred Twin-Spot Carpet in Detroit on a given day, against under 5% in June and September–March, the lowest months.
Between 9 pm and midnight
Across all the parks we cover, that three-hour window holds the most Dark-Barred Twin-Spot Carpet 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.
Among the best
Of the 12 cities where we can rate Dark-Barred Twin-Spot Carpet sightings, Detroit ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Porto (Portugal, about 10%).
Same family: Geometridae
The closest relatives of the Dark-Barred Twin-Spot Carpet that you can see in Detroit (family Geometridae, Geometer Moths) are Chickweed Geometer Moth (about 10%), Lesser Maple Spanworm Moth (about 10%) and Pale Beauty (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Dark-Barred Twin-Spot Carpet is recorded against all the insects logged in Detroit (14 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.
