Catocala junctura
In 3 days ~10% in a week ~30%
Catocala junctura, the joined underwing or Stretch's underwing, is a moth in the family Erebidae. The species was first described by Francis Walker in 1858. It is found throughout temperate North America, ranging from New York and Pennsylvania west to Montana, Colorado, Oklahoma, Arizona, and into Texas, and north to southern Illinois, extreme southern Alberta and Saskatchewan; it has also been recorded west of the Rocky Mountains from California and south-eastern British Columbia. It is typically found near water, where the food plants of its caterpillar larvae grow plentifully.
The wingspan is 70–75 mm or more. The forewings are grayish to brownish with prominent black bands above, and whitish below. The upperside of the hindwings is orange red, with two roughly concentric blackish bands on each wing, and lacking hairs at the base. The outer band separates a margin that is lighter in color than the rest of the upper hindwing. The inner band does not reach the trailing edge; its hindward tip forms a hook which points back at the wing base, or almost so. The underside of the hindwings is whitish along the leading edge; the trailing three-quarters of the... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Denver | 🇺🇸 United States | |
| 2 | Chicago | 🇺🇸 United States | |
| 3 | San Diego | 🇺🇸 United States | |
| 4 | Los Angeles | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Joined Underwing Moth sighting in Denver on a given day, based on 31 verified sightings from GBIF citizen-science data. It is the 151st most-seen of the 461 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.
July–August and October
In those months about 10% of wildlife watchers report a Joined Underwing Moth in Denver on a given day, against under 5% in September and November–June, the lowest months.
Yes
Of the 4 cities where we can rate Joined Underwing Moth sightings, Denver has the highest daily chance: under 5%. Next come Chicago (United States, under 5%) and San Diego (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Joined Underwing Moth is recorded against all the insects logged in Denver (31 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.
