Copestylum mexicanum
In 3 days ~20% in a week ~30%
Copestylum mexicanum, the Mexican cactus fly, is a species of syrphid fly in the family Syrphidae. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States | |
| 2 | Big Bend National Park | 🇺🇸 United States | |
| 3 | Everglades National Park | 🇺🇸 United States | |
| 4 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San Diego | 🇺🇸 United States | |
| 2 | Los Angeles | 🇺🇸 United States | |
| 3 | Sacramento | 🇺🇸 United States | |
| 4 | Mexico City | 🇲🇽 México | |
| 5 | Monterrey | 🇲🇽 México | |
| 6 | Mesa | 🇺🇸 United States | |
| 7 | San Antonio | 🇺🇸 United States | |
| 8 | Phoenix | 🇺🇸 United States | |
| 9 | Austin | 🇺🇸 United States | |
| 10 | San Francisco | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Mexican Cactus Fly sighting in Big Bend National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 255th most-seen of the 329 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
April–July and September
In those months about 10% of wildlife watchers report a Mexican Cactus Fly in Big Bend National Park on a given day, against under 5% in August and October–March, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Mexican Cactus Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 4 parks where we can rate Mexican Cactus Fly sightings, Big Bend National Park ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Saguaro National Park (United States, about 10%).
Same genus: Copestylum
The closest relatives of the Mexican Cactus Fly that you can see in Big Bend National Park (genus Copestylum, Bromeliad Flies) are Yellow-Spotted Bromeliad Fly (about 10%) and Copestylum marginatum (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Mexican Cactus Fly is recorded against all the insects logged in Big Bend National Park (6 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.
