Lambdina fiscellaria
In 3 days ~30% in a week ~50%
Lambdina fiscellaria, the mournful thorn or hemlock looper, is a moth of the family Geometridae. It is found in North America, from the Pacific to the Atlantic coast and from Canada south to Pennsylvania, Wisconsin and California.
The wingspan is about 35 mm. The moth flies from August to early October depending on the location. The larvae feed on hemlock, balsam fir, white spruce, oak and other hardwoods. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Gros Morne National Park | 🇨🇦 Canada | |
| 2 | Acadia National Park | 🇺🇸 United States | |
| 3 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 4 | Olympic National Park | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Hemlock Looper Moth sighting in Acadia National Park on a given day, based on 33 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 85th most-seen of the 405 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
August to October
In those months about 20% of wildlife watchers report a Hemlock Looper Moth in Acadia National Park on a given day, against under 5% in November to July, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Hemlock Looper Moth sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
2nd of 4
Of the 4 parks where we can rate Hemlock Looper Moth sightings, Acadia National Park ranks 2nd at about 10%. The best odds are in Gros Morne National Park (Canada, about 30%).
Same family: Geometridae
The closest relatives of the Hemlock Looper Moth that you can see in Acadia National Park (family Geometridae, Geometer Moths) are Sweetfern Geometer Moth (about 10%), Pale Beauty (about 10%) and Gray Spruce Looper Moth (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Hemlock Looper Moth is recorded against all the insects logged in Acadia National Park (33 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.
