Drepana arcuata
In 3 days ~30% in a week ~50%
Drepana arcuata, the arched hooktip or masked birch caterpillar, is a moth of the family Drepanidae. The species was first described by Francis Walker in 1855. It is found from Newfoundland to Vancouver Island, south to at least North Carolina, South Carolina and California.
The wingspan is 24–40 millimetres (0.94–1.57 in). Adults are on wing from mid-May through late-July. There is one generation per year in the north. The larvae feed on Betula papyrifera and Alnus species, which they may use as a medium to communicate. Sound is produced by shaking their bodies, drumming and scraping their mouthparts, or dragging specialised anal "oars" against the surface of a leaf. Larvae build communal silk shelters and the sounds may attract other larva to the shelter. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Gros Morne National Park | 🇨🇦 Canada | |
| 2 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 3 | Acadia National Park | 🇺🇸 United States | |
| 4 | Shenandoah National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Boston | 🇺🇸 United States | |
| 2 | Montreal | 🇨🇦 Canada | |
| 3 | Toronto | 🇨🇦 Canada | |
| 4 | New York City | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report an Arched Hooktip Moth sighting in Acadia National Park on a given day, based on 29 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 100th 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.
June
In that month about 20% of wildlife watchers report an Arched Hooktip Moth in Acadia National Park on a given day, against under 5% in September to April, the lowest months.
Between 9 pm and midnight
Across all the parks we cover, that three-hour window holds the most Arched Hooktip Moth sightings with a recorded time, and about 6 in 10 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 Arched Hooktip Moth sightings, Acadia National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Gros Morne National Park (Canada, about 10%) and Great Smoky Mountains National Park (United States, about 10%).
Same family: Drepanidae
The closest relatives of the Arched Hooktip Moth that you can see in Acadia National Park (family Drepanidae, Hooktip and False Owlet Moths) are Rose Hooktip (about 10%) and Two-Lined Hooktip (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Arched Hooktip Moth is recorded against all the insects logged in Acadia National Park (29 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.
