Castniomera atymnius
In 3 days ~40% in a week ~70%
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 Gandoca-Manzanillo Wildlife Refuge on a given day, based on 12 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 22nd most-seen of the 72 insects we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
March, May and December
In those months about 30% of wildlife watchers report a Screwworm in Gandoca-Manzanillo Wildlife Refuge on a given day, against under 5% in April and June–November, the lowest months.
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.
Among the best
Of the 12 parks where we can rate Screwworm sightings, Gandoca-Manzanillo Wildlife Refuge ranks 2nd at about 20%, level with the leaders once rounded. The best odds are in Tortuguero National Park (Costa Rica, about 20%).
Same order: Lepidoptera
The closest relatives of the Screwworm that you can see in Gandoca-Manzanillo Wildlife Refuge (order Lepidoptera, Butterflies and Moths) are Malachite (about 40%), Banded Peacock (about 40%) and White Peacock (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 Gandoca-Manzanillo Wildlife Refuge (12 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.
