Acharia stimulea
In 3 days ~20% in a week ~40%
The saddleback caterpillar (Acharia stimulea, formerly Sibine stimulea) is the larva of a species of moth native to eastern North America. It is also found in Mexico. The species belongs to the family of slug caterpillars, Limacodidae.
The larva (caterpillar) is primarily green with brown at both ends and a prominent white-ringed brown dot in the center which resembles a saddle. It has a pair of fleshy horns at both ends. These and most of the rest of the body bear urticating hairs that secrete an irritating venom. Contact with the hairs causes a painful, swollen rash and sometimes nausea in humans. In some cases, more severe reactions to the venom can occur, including a systemic condition called erucism or acute urticaria, for which severe symptoms may include migraines, gastrointestinal symptoms, asthma complications, anaphylactic shock, rupturing of erythrocytes, and hemorrhaging. The hairs should be removed from the skin immediately to prevent more venom spread. The cocoon may also have irritating hairs, and hairs from the larva can fall on surrounding objects.
The larvae feed on plants. In Florida and Alabama in the United States, it feeds on palms such as the Manila palm (Adonidia merrillii). Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 2 | Point Pelee National Park | 🇨🇦 Canada | |
| 3 | Shenandoah National Park | 🇺🇸 United States | |
| 4 | Everglades National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Baltimore | 🇺🇸 United States | |
| 2 | Philadelphia | 🇺🇸 United States | |
| 3 | Washington | 🇺🇸 United States | |
| 4 | Miami | 🇺🇸 United States | |
| 5 | New York City | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Saddleback Caterpillar Moth sighting in Shenandoah National Park on a given day, based on 15 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 251st most-seen of the 723 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.
September
In that month about 20% of wildlife watchers report a Saddleback Caterpillar Moth in Shenandoah National Park on a given day, against under 5% in November to July, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Saddleback Caterpillar Moth sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 4 parks where we can rate Saddleback Caterpillar Moth sightings, Shenandoah National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Great Smoky Mountains National Park (United States, about 10%) and Point Pelee National Park (Canada, about 10%).
Same family: Limacodidae
The closest relatives of the Saddleback Caterpillar Moth that you can see in Shenandoah National Park (family Limacodidae, Slug Caterpillar Moths) are Skiff Moth (about 10%), Crowned Slug Moth (about 10%) and Smaller Parasa Moth (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Saddleback Caterpillar Moth is recorded against all the insects logged in Shenandoah National Park (15 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.
