Drepana arcuata
In 3 days ~10%
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 |
Rare
Under 5% of wildlife watchers report an Arched Hooktip Moth sighting in Toronto on a given day, based on 10 verified sightings from GBIF citizen-science data. It is the 1068th most-seen of the 1689 insects we can rate there. Over three days the chance rises to about 10%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report an Arched Hooktip Moth in Toronto on a given day, so our monthly data shows no clear season.
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 cities where we can rate Arched Hooktip Moth sightings, Toronto ranks 3rd at under 5%, level with the leaders once rounded. The best odds are in Boston (United States, under 5%) and Montreal (Canada, under 5%).
GBIF citizen-science records
It is estimated from how often the Arched Hooktip Moth is recorded against all the insects logged in Toronto (10 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.
