Catocala ultronia
In 3 days ~10% in a week ~30%
Catocala ultronia, the dark red underwing or ultronia underwing, is a moth of the family Erebidae. The species was first described by Jacob Hübner in 1823. It is found in most of eastern North America, south to Florida and Texas. It ranges west across the southern parts of Canada to extreme southeast British Columbia.
The wingspan is 46–60 mm. Adults are on wing in August in one generation depending on the location. The larvae feed on Fraxinus pennsylvanica, Malus species, Populus grandidentata, Prunus pensylvanica, Prunus serotina, Prunus virginiana, and Tilia americana. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Baltimore | 🇺🇸 United States | |
| 2 | Boston | 🇺🇸 United States | |
| 3 | New York City | 🇺🇸 United States | |
| 4 | Washington | 🇺🇸 United States | |
| 5 | Toronto | 🇨🇦 Canada |
Rare
Under 5% of wildlife watchers report an Ultronia Underwing sighting in Great Smoky Mountains National Park on a given day, based on 10 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 513th most-seen of the 822 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
June and July
In those months about 10% of wildlife watchers report an Ultronia Underwing in Great Smoky Mountains National Park on a given day, against under 5% in August to May, the lowest months.
Between 9 pm and midnight
Across all the parks we cover, that three-hour window holds the most Ultronia Underwing sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Only Great Smoky Mountains National Park, in our data
Great Smoky Mountains National Park is the only park on Wallace's Line with enough records to rate Ultronia Underwing sightings: under 5% of wildlife watchers there report one on a given day.
Same genus: Catocala
The closest relatives of the Ultronia Underwing that you can see in Great Smoky Mountains National Park (genus Catocala, Underwing Moths) are Ilia Underwing (about 10%) and Epione Underwing (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Ultronia Underwing is recorded against all the insects logged in Great Smoky Mountains National Park (10 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.
