Therinia transversaria
In 3 days ~20% in a week ~50%
Therinia transversaria is a swallow-tailed moth in the family Saturniidae and the genus Therinia. It can be commonly mistaken for Urapteroides astheniata. It was discovered by Herbert Druce in 1887. It is also extremely similar to Therinia Terminalis, with the notable difference being a small orange patch on the rear wings. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Braulio Carrillo National Park | 🇨🇷 Costa Rica | |
| 2 | Arenal Volcano National Park | 🇨🇷 Costa Rica | |
| 3 | Tapantí-Macizo de la Muerte National Park | 🇨🇷 Costa Rica |
With luck
About 10% of wildlife watchers report a Therinia transversaria sighting in Arenal Volcano National Park on a given day, based on 18 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 68th 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 50%, if each day is a fresh chance.
April, June and August
In those months about 20% of wildlife watchers report a Therinia transversaria in Arenal Volcano National Park on a given day, against under 5% in May and September–January, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Therinia transversaria sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
Among the best
Of the 3 parks where we can rate Therinia transversaria sightings, Arenal Volcano National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Braulio Carrillo National Park (Costa Rica, about 10%).
Same family: Saturniidae
The closest relatives of the Therinia transversaria that you can see in Arenal Volcano National Park (family Saturniidae, Emperor and Giant Silk Moths) are Pseudodirphia menander (about 10%), Orizaba Silkmoth (about 10%) and Automeris postalbida (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Therinia transversaria is recorded against all the insects logged in Arenal Volcano National Park (18 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.
