Idia aemula
In 3 days ~20% in a week ~30%
Idia aemula, the common idia, powdered snout or waved tabby, is a litter moth of the family Erebidae. The species was first described by Jacob Hübner in 1813. It is found from Canada south to Florida and Texas. It has been reported in the Palearctic.
The ground colour of both wings is medium grey. The basal, antemedial, postmedial lines are darker and thin. There is a more diffuse median line and sometimes a median shade. A pale subterminal line is preceded by a dark shade. The reniform spot is large and pale or warm ochre to orange brown. The hindwing has several wavy light and dark lines and a dark discal spot. The wingspan is 20–30 mm. In North America, adults are on wing from May to October in the north and from April to November in the south. There are two to three generations per year.
The larvae feed on dead leaves. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Acadia National Park | 🇺🇸 United States | |
| 2 | Shenandoah National Park | 🇺🇸 United States | |
| 3 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dallas | 🇺🇸 United States | |
| 2 | Baltimore | 🇺🇸 United States | |
| 3 | Austin | 🇺🇸 United States | |
| 4 | Boston | 🇺🇸 United States | |
| 5 | Washington | 🇺🇸 United States | |
| 6 | Chicago | 🇺🇸 United States | |
| 7 | Edmonton | 🇨🇦 Canada | |
| 8 | Toronto | 🇨🇦 Canada | |
| 9 | Montreal | 🇨🇦 Canada | |
| 10 | Philadelphia | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Common Idia Moth sighting in Great Smoky Mountains National Park on a given day, based on 14 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 334th most-seen of the 822 insects we can rate there. Over three days the chance rises to about 20%, 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 Common Idia Moth in Great Smoky Mountains National Park on a given day, against under 5% in September and November–June, the lowest months.
Between 9 pm and midnight
Across all the parks we cover, that three-hour window holds the most Common Idia Moth 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 3 parks where we can rate Common Idia Moth sightings, Great Smoky Mountains National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Acadia National Park (United States, about 10%) and Shenandoah National Park (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Common Idia Moth is recorded against all the insects logged in Great Smoky Mountains National Park (14 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.
