Halysidota harrisii
In 3 days ~20% in a week ~40%
Halysidota harrisii, the sycamore tiger moth, is a moth belonging to the family Erebidae and the tribe Arctiini, the tiger moths. The species was first described by Benjamin Dann Walsh in 1864. It is found in southeastern Canada, the eastern parts of the United States, and northeastern Mexico.
The larvae have yellow-orange heads and bodies covered with hair, and they can grow to approximately 25–35 mm in length. They exhibit two pairs of long, orange hair-pencils and two pairs of white hair-pencils towards the front of their body. They also exhibit one pair of white hair-pencils near the back of their body.
The adults are pale yellow with dark bands on the forewings. Each forewing is 24–26 mm in length, making the wingspan approximately 50 mm. As adults, they are almost indistinguishable from the closely related Halysidota tesselaris.
The sycamore tiger moth produces two generations each year. Moths emerge from overwintering cocoons from May to June. After mating, they lay egg masses on bark and the underside of leaves. The larvae feed on the American sycamore tree, Platanus occidentalis. They pupate in late June and July, and emerge as moths in July... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 2 | Shenandoah National Park | 🇺🇸 United States | |
| 3 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Detroit | 🇺🇸 United States | |
| 2 | Baltimore | 🇺🇸 United States | |
| 3 | Philadelphia | 🇺🇸 United States | |
| 4 | New York City | 🇺🇸 United States | |
| 5 | Washington | 🇺🇸 United States | |
| 6 | Chicago | 🇺🇸 United States | |
| 7 | Boston | 🇺🇸 United States | |
| 8 | Houston | 🇺🇸 United States | |
| 9 | Monterrey | 🇲🇽 México | |
| 10 | Austin | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Sycamore Tussock Moth sighting in Philadelphia on a given day, based on 70 verified sightings from GBIF citizen-science data. It is the 101st most-seen of the 632 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.
July
In that month about 20% of wildlife watchers report a Sycamore Tussock Moth in Philadelphia on a given day, against under 5% in September to June, the lowest months.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Sycamore Tussock 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.
Among the best
Of the 11 cities where we can rate Sycamore Tussock Moth sightings, Philadelphia ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Detroit (United States, about 10%) and Baltimore (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Sycamore Tussock Moth is recorded against all the insects logged in Philadelphia (70 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.
