Harrisina americana
In 3 days ~30% in a week ~50%
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 Montreal on a given day, based on 223 verified sightings from GBIF citizen-science data. It is the 54th most-seen of the 926 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
July
In that month about 20% of wildlife watchers report a Grapeleaf Skeletonizer Moth in Montreal on a given day, against under 5% in February–May and October–December, 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 15 cities where we can rate Grapeleaf Skeletonizer Moth sightings, Montreal has the highest daily chance: about 10%. Next come Houston (United States, about 10%) and Baltimore (United States, about 10%).
Same order: Lepidoptera
The closest relatives of the Grapeleaf Skeletonizer Moth that you can see in Montreal (order Lepidoptera, Butterflies and Moths) are Common Blue (about 40%), Monarch (about 30%) and Black Swallowtail (about 20%), 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 Montreal (223 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.
