Harrisina americana
In 3 days ~20% in a week ~40%
The grapeleaf skeletonizer (Harrisina americana) is a moth in the family Zygaenidae. It is widespread in the eastern half of the United States, and commonly noticed defoliating grapes, especially of the Virginia creeper (Parthenocissus quinquefolia). The western grapeleaf skeletonizer (Harrisina metallica) is very similar to and slightly larger than H. americana, but their distributions are different.
Members of this family all produce HCN (hydrogen cyanide) a potent antipredator toxin. The adult has narrow black wings, usually held away from the body at rest, and a reddish collar. The wingspan is 18–28 mm, the length 8–12 mm.
The larva has a dark head; the body is yellow with a complete black band across each abdominal segment. The larvae can reach up to 15 mm in length. There are several generations per year in the south, and one in the north of its range.
Eggs are lemon yellow, shaped like a capsule, slightly over 0.5 mm in length and are laid in clusters on the underside of leaves. They hatch in about a week. Larvae are stout, with ten bright yellow bands or lines of dots, and eleven black bands alternating. They have... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Shenandoah National Park | 🇺🇸 United States | |
| 2 | Everglades National Park | 🇺🇸 United States | |
| 3 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Montreal | 🇨🇦 Canada | |
| 2 | Houston | 🇺🇸 United States | |
| 3 | Baltimore | 🇺🇸 United States | |
| 4 | Detroit | 🇺🇸 United States | |
| 5 | Philadelphia | 🇺🇸 United States | |
| 6 | Orlando | 🇺🇸 United States | |
| 7 | Boston | 🇺🇸 United States | |
| 8 | Washington | 🇺🇸 United States | |
| 9 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 10 | Dallas | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Grapeleaf Skeletonizer Moth sighting in Shenandoah National Park on a given day, based on 13 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 284th 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.
May to July
In those months about 10% of wildlife watchers report a Grapeleaf Skeletonizer Moth in Shenandoah National Park on a given day, against under 5% in August to April, the lowest months.
Between 8 and 11 am
Across all the parks we cover, that three-hour window holds the most Grapeleaf Skeletonizer 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.
Yes
Of the 3 parks where we can rate Grapeleaf Skeletonizer Moth sightings, Shenandoah National Park has the highest daily chance: about 10%. Next come Everglades National Park (United States, about 10%) and Great Smoky Mountains National Park (United States, under 5%).
Same family: Zygaenidae
The closest relatives of the Grapeleaf Skeletonizer Moth that you can see in Shenandoah National Park (family Zygaenidae, Burnet Moths) are Orange-Patched Smoky Moth (about 10%) and Clemens' False Skeletonizer (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Grapeleaf Skeletonizer Moth is recorded against all the insects logged in Shenandoah National Park (13 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.
