Orgyia leucostigma
In 3 days ~10% in a week ~20%
Orgyia leucostigma, the white-marked tussock moth, is a moth in the family Erebidae. The species was first described by James Edward Smith in 1797. The caterpillar is very common especially in late summer in eastern North America, extending as far west as Texas, California, and Alberta.
The genus name Orgyia is from the ancient Greek word ὄργυια, órgyia - 'outstretched arms'. So named because, when at rest, the moth stretches forward its forelegs like arms. Two or more generations occur per year in eastern North America. They overwinter in the egg stage.
Eggs are laid in a single mass over the cocoon of the female, and covered in a froth. Up to 300 eggs are laid at a time. The larvae are brightly colored, with tufts of hair-like setae. The head is bright red and the body has yellow or white stripes, with a black stripe along the middle of the back. Bright red defensive glands are seen on the hind end of the back. Four white toothbrush-like tufts stand out from the back, and a gray-brown hair pencil is at the hind end. The four white tufts on the larva's back may mimic the cocoons of parasitic wasps. Touching the hairs sets off... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Gros Morne National Park | 🇨🇦 Canada | |
| 2 | Congaree National Park | 🇺🇸 United States | |
| 3 | Point Pelee National Park | 🇨🇦 Canada | |
| 4 | Acadia National Park | 🇺🇸 United States | |
| 5 | Shenandoah National Park | 🇺🇸 United States | |
| 6 | Riding Mountain National Park | 🇨🇦 Canada | |
| 7 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Chicago | 🇺🇸 United States | |
| 2 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 3 | Baltimore | 🇺🇸 United States | |
| 4 | Toronto | 🇨🇦 Canada | |
| 5 | Washington | 🇺🇸 United States | |
| 6 | Detroit | 🇺🇸 United States | |
| 7 | Montreal | 🇨🇦 Canada | |
| 8 | Dallas | 🇺🇸 United States | |
| 9 | Philadelphia | 🇺🇸 United States | |
| 10 | New York City | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a White-Marked Tussock Moth sighting in Philadelphia on a given day, based on 6 verified sightings from GBIF citizen-science data. It is the 510th most-seen of the 632 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a White-Marked Tussock Moth in Philadelphia on a given day, so our monthly data shows no clear season.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most White-Marked 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.
9th of 10
Of the 10 cities where we can rate White-Marked Tussock Moth sightings, Philadelphia ranks 9th at under 5%. The best odds are in Chicago (United States, about 10%), Minneapolis [Saint Paul] (United States, about 10%) and Baltimore (United States, about 10%).
Same family: Erebidae
The closest relatives of the White-Marked Tussock Moth that you can see in Philadelphia (family Erebidae, Underwing, Tiger, Tussock, and Allied Moths) are Giant Leopard Moth (about 10%), Isabella Tiger Moth (about 10%) and Green Cloverworm Moth (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the White-Marked Tussock Moth is recorded against all the insects logged in Philadelphia (6 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.
