Citheronia regalis
In 3 days ~10% in a week ~20%
Citheronia regalis, the regal moth or royal walnut moth, is a North American moth in the family Saturniidae. The caterpillars are called hickory horned devils. The adult (imago) has a wingspan of 3.75–6.1 in (9.5–15.5 cm). The species was first described by Johan Christian Fabricius in 1793.
The adult moth is the largest moth by mass in latitudes north of Mexico, as are the spectacular larva and the substantial pupa. The life cycle of the moth is typical of the Saturniidae species, and typical of the Ceratocampinae. It burrows into the ground to pupate in an earthen chamber, rather than spinning a cocoon.
Its eggs are yellowish, ovular and 2 mm in diameter. They are laid either singly or in groups of up to four on the upper surface of the host plant leaves, favoring nut trees such as Juglans and Carya (walnuts and hickories). There are regional preferences, with the utilization of sweet gum and persimmon in the south, and sumacs where the others are not available. Larvae are solitary in later stages and rarely occur in numbers large enough to cause defoliation; however, an individual larva can strip several branches of their leaves during the ravenous fifth instar.... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States | |
| 2 | Shenandoah National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States | |
| 2 | Philadelphia | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Regal Moth sighting in Philadelphia on a given day, based on 5 verified sightings from GBIF citizen-science data. It is the 557th 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.
August
In that month about 10% of wildlife watchers report a Regal Moth in Philadelphia on a given day, against under 5% in September to July, the lowest months.
Between 7 and 10 am
Across all the parks we cover, that three-hour window holds the most Regal Moth sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 2 cities where we can rate Regal Moth sightings, Philadelphia ranks 2nd at under 5%, level with the leaders once rounded. The best odds are in Washington (United States, under 5%).
Same family: Saturniidae
The closest relatives of the Regal Moth that you can see in Philadelphia (family Saturniidae, Emperor and Giant Silk Moths) are Polyphemus Moth (about 10%) and North American Luna Moth (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Regal Moth is recorded against all the insects logged in Philadelphia (5 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.
