Asterocampa leilia
In 3 days ~70% in a week >90%
Asterocampa leilia, the Empress Leilia, Leilia hackberry butterfly or desert hackberry, is a species of butterfly in the family Nymphalidae. Adults are brownish orange, with white and black spots on the bottom of the wings. The length of the wings is 1.5 to 2 inches (38 to 51 mm).
The species can be found in the south-western United States, including Arizona and Texas, as well as Mexico. Adults feed on dung, sap and rotten fruit. In very rare cases the species will feed on nectar. They live in canyons, streamsides, thorn scrubs, and washes. Males of the species will wait near their food plants for females to appear. Larvae feed on hackberry. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Big Bend National Park | 🇺🇸 United States | |
| 2 | Saguaro National Park | 🇺🇸 United States | |
| 3 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Mesa | 🇺🇸 United States | |
| 2 | Phoenix | 🇺🇸 United States | |
| 3 | Monterrey | 🇲🇽 México | |
| 4 | San Antonio | 🇺🇸 United States |
Likely
About 40% of wildlife watchers report an Empress Leilia sighting in Big Bend National Park on a given day, based on 200 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the most-seen of the 329 insects we can rate there. Over three days the chance rises to about 70%, and over a week to over 90%, if each day is a fresh chance.
September and October
In those months about 50% of wildlife watchers report an Empress Leilia in Big Bend National Park on a given day, against under 5% in January and February, the lowest months. Those are among Big Bend National Park's wettest months, with about 35 mm of rain a month against 10 mm in April.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Empress Leilia sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 3 parks where we can rate Empress Leilia sightings, Big Bend National Park has the highest daily chance: about 40%. Next come Saguaro National Park (United States, about 30%) and Cumbres de Monterrey National Park (Mexico, under 5%).
GBIF citizen-science records
It is estimated from how often the Empress Leilia is recorded against all the insects logged in Big Bend National Park (200 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.
