Catocala ultronia
In 3 days ~10% in a week ~20%
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 Boston on a given day, based on 11 verified sightings from GBIF citizen-science data. It is the 695th most-seen of the 1200 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.
August
In that month about 10% of wildlife watchers report an Ultronia Underwing in Boston on a given day, against under 5% in September to July, 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.
Among the best
Of the 5 cities where we can rate Ultronia Underwing sightings, Boston ranks 2nd at under 5%, level with the leaders once rounded. The best odds are in Baltimore (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Ultronia Underwing is recorded against all the insects logged in Boston (11 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.
