Thysania agrippina
In 3 days ~20% in a week ~40%
Thysania agrippina is a species of moth in the family Erebidae. It was described by Maria Sibylla Merian in her 1705 publication Metamorphosis insectorum Surinamensium, and Pieter Cramer provided the formal description of the species in 1776. The most commonly accepted English name is the white witch. Other common names include the ghost moth, great gray witch and great owlet moth. Thysania agrippina is of interest as a competitor for title of "largest insect". This may be true by the measure of wingspan—a Brazilian specimen with a wingspan of almost 30 cm (12 in) appears to hold the record. The Atlas moth and Hercules moth, however, have greater wing areas. The white witch occurs from Uruguay to Mexico, and appears as a stray as far north as Texas in the U.S. Collection dates shows no discernible pattern with respect to location or season.
One story of the derivation of the common name: early naturalists collected specimens of birds and bats with shotguns. An enormous darting flyer high in the canopy was a tempting target. Firing a cloud of pellets at a white witch moth did not necessarily bring it down, however, because the body is small relative to the wing area.... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Serra dos Órgãos National Park | 🇧🇷 Brazil | |
| 2 | Yasuní National Park | 🇪🇨 Ecuador | |
| 3 | Arenal Volcano National Park | 🇨🇷 Costa Rica | |
| 4 | La Amistad International Park (Panama) | 🇵🇦 Panama | |
| 5 | Tapantí-Macizo de la Muerte National Park | 🇨🇷 Costa Rica | |
| 6 | Monteverde Cloud Forest Reserve | 🇨🇷 Costa Rica |
With luck
About 10% of wildlife watchers report a White Witch sighting in Arenal Volcano National Park on a given day, based on 10 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 129th most-seen of the 302 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
In that month about 20% of wildlife watchers report a White Witch in Arenal Volcano National Park on a given day, against under 5% in January, March–April and July–November, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most White Witch sightings with a recorded time, and about half of them come between 6 pm and 6 am: it is seen both by day and at night.
Among the best
Of the 6 parks where we can rate White Witch sightings, Arenal Volcano National Park ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Serra dos Órgãos National Park (Brazil, about 10%) and Yasuní National Park (Ecuador, about 10%).
Same family: Erebidae
The closest relatives of the White Witch that you can see in Arenal Volcano National Park (family Erebidae, Underwing, Tiger, Tussock, and Allied Moths) are Feigeria herilia (about 10%), Black Witch (about 10%) and Dysgonia purpurata (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the White Witch is recorded against all the insects logged in Arenal Volcano National Park (10 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.
