Castniomera atymnius
In 3 days ~50% in a week ~80%
Castniomera is a monotypic genus of moths in the family Castniidae described by Constant Vincent Houlbert in 1918. Its single species, Castniomera atymnius, commonly known as the giant butterfly-moth, was first described by Johan Wilhelm Dalman in 1824. It is known from Mexico through Central America to Venezuela.
The larvae feed on Musaceae species. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Tortuguero National Park | 🇨🇷 Costa Rica | |
| 2 | Gandoca-Manzanillo Wildlife Refuge | 🇨🇷 Costa Rica | |
| 3 | Masaya Volcano National Park | 🇳🇮 Nicaragua | |
| 4 | Tenorio Volcano National Park | 🇨🇷 Costa Rica | |
| 5 | Piedras Blancas National Park | 🇨🇷 Costa Rica | |
| 6 | Braulio Carrillo National Park | 🇨🇷 Costa Rica | |
| 7 | Arenal Volcano National Park | 🇨🇷 Costa Rica | |
| 8 | Corcovado National Park | 🇨🇷 Costa Rica | |
| 9 | Soberanía National Park | 🇵🇦 Panama | |
| 10 | Cahuita National Park | 🇨🇷 Costa Rica | |
| 11 | Manuel Antonio National Park | 🇨🇷 Costa Rica | |
| 12 | Parque Natural Metropolitano | 🇵🇦 Panama |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San Salvador | 🇸🇻 El Salvador | |
| 2 | San José | 🇨🇷 Costa Rica | |
| 3 | Panama City | 🇵🇦 Panama |
Possible
About 20% of wildlife watchers report a Screwworm sighting in Tortuguero National Park on a given day, based on 25 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 16th most-seen of the 80 insects we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
February
In that month about 30% of wildlife watchers report a Screwworm in Tortuguero National Park on a given day, against under 5% in April and November, the lowest months. That is one of Tortuguero National Park's driest months, with about 160 mm of rain against 540 mm in July.
Between noon and 3 pm
Across all the parks we cover, that three-hour window holds the most Screwworm 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 12 parks where we can rate Screwworm sightings, Tortuguero National Park has the highest daily chance: about 20%. Next come Gandoca-Manzanillo Wildlife Refuge (Costa Rica, about 20%) and Masaya Volcano National Park (Nicaragua, about 20%).
Same order: Lepidoptera
The closest relatives of the Screwworm that you can see in Tortuguero National Park (order Lepidoptera, Butterflies and Moths) are Banded Peacock (about 40%), White Peacock (about 30%) and Banded Owl-Butterfly (about 30%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Screwworm is recorded against all the insects logged in Tortuguero National Park (25 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.
