Tetracis crocallata
In 3 days ~20% in a week ~40%
Tetracis crocallata is a moth of the family Geometridae first described by Achille Guenée in 1858. It is found in North America from Nova Scotia, New Brunswick, southern Manitoba and southern Saskatchewan to Alberta, south to northern Florida, west to Kansas, Nebraska, North Dakota and extreme eastern Texas.
The length of the forewings 17–25 mm. Adults are on wing from May to August depending on the location. There are two generations in New York and southward. The larvae feed on Alnus, Castanea and Salix species. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Point Pelee National Park | 🇨🇦 Canada | |
| 2 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 3 | Shenandoah National Park | 🇺🇸 United States | |
| 4 | Acadia National Park | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Yellow Slant-Line sighting in Great Smoky Mountains National Park on a given day, based on 28 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 184th 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 40%, if each day is a fresh chance.
April to July
In those months about 10% of wildlife watchers report a Yellow Slant-Line in Great Smoky Mountains National Park on a given day, against under 5% in August to March, the lowest months.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Yellow Slant-Line sightings with a recorded time, and about half of them come between 6 am and 6 pm: it is seen both by day and at night.
Among the best
Of the 4 parks where we can rate Yellow Slant-Line sightings, Great Smoky Mountains National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Point Pelee National Park (Canada, about 10%).
GBIF citizen-science records
It is estimated from how often the Yellow Slant-Line is recorded against all the insects logged in Great Smoky Mountains National Park (28 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.
