Hemiargus ceraunus
In 3 days ~50% in a week ~80%
Hemiargus ceraunus, the Ceraunus blue, is a species of butterfly in the family Lycaenidae. The species was first described by Johan Christian Fabricius in 1793. It is found in the southwestern United States, southern Texas, Florida and the Florida Keys south through the West Indies, Mexico and Central America to South America. Strays may be found in North Carolina, Missouri, Kansas and Nevada. The habitat consists of open woodland, desert scrub, dunes, pastures, road edges and vacant lots.
The wingspan is 20–30 mm. Adults are on wing year round in Texas and southern Florida and in late summer in other parts of the range. Adults feed on flower nectar. The larvae feed on the flowers and seedpods of various woody legumes, including Chamaecrista fasciculata, Abrus precatorius and Prosopis species. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Padre Island National Seashore | 🇺🇸 United States | |
| 2 | Ría Lagartos Biosphere Reserve | 🇲🇽 Mexico | |
| 3 | Merritt Island National Wildlife Refuge | 🇺🇸 United States | |
| 4 | Bahía de Loreto National Park | 🇲🇽 Mexico | |
| 5 | Everglades National Park | 🇺🇸 United States | |
| 6 | Cabo Pulmo National Park | 🇲🇽 Mexico | |
| 7 | Saguaro National Park | 🇺🇸 United States | |
| 8 | Joshua Tree National Park | 🇺🇸 United States | |
| 9 | Big Cypress National Preserve | 🇺🇸 United States | |
| 10 | Gandoca-Manzanillo Wildlife Refuge | 🇨🇷 Costa Rica | |
| 11 | Cumbres de Monterrey National Park | 🇲🇽 Mexico | |
| 12 | Cañón del Sumidero National Park | 🇲🇽 Mexico |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Santo Domingo | 🇩🇴 Dominican Republic | |
| 2 | San Antonio | 🇺🇸 United States | |
| 3 | San Pedro Sula | 🇭🇳 Honduras | |
| 4 | Torreón | 🇲🇽 México | |
| 5 | Monterrey | 🇲🇽 México | |
| 6 | Austin | 🇺🇸 United States | |
| 7 | Miami | 🇺🇸 United States | |
| 8 | Mesa | 🇺🇸 United States | |
| 9 | Phoenix | 🇺🇸 United States | |
| 10 | Orlando | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Ceraunus Blue sighting in Joshua Tree National Park on a given day, based on 75 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 29th most-seen of the 190 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.
June
In that month about 30% of wildlife watchers report a Ceraunus Blue in Joshua Tree National Park on a given day, against about 10% in February and December, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Ceraunus Blue sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
8th of 12
Of the 12 parks where we can rate Ceraunus Blue sightings, Joshua Tree National Park ranks 8th at about 20%. The best odds are in Padre Island National Seashore (United States, about 30%), Ría Lagartos Biosphere Reserve (Mexico, about 30%) and Merritt Island National Wildlife Refuge (United States, about 30%).
Same family: Lycaenidae
The closest relatives of the Ceraunus Blue that you can see in Joshua Tree National Park (family Lycaenidae, Gossamer-winged Butterflies) are Great Purple Hairstreak (about 30%), Marine Blue (about 20%) and Western Pygmy-Blue (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Ceraunus Blue is recorded against all the insects logged in Joshua Tree National Park (75 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.
