Thermonectus marmoratus
In 3 days ~10% in a week ~30%
Thermonectus marmoratus is a relatively colorful North American species of diving beetle known by the common names sunburst diving beetle and yellow-spotted diving beetle. The behavior of this diving beetle has been compared to a scuba diver, since it carries with it a bubble of air as it dives down into the water. Its aquatic larval stage was the first ever recorded use of bifocals in the animal world. The beetle uses in its principal eyes two retinas and two distinct focal planes that are substantially separated, in the manner of bifocals to switch their vision from up-close to distance, for easy and efficient capture of their prey.
Because of their bright aposematic colors, they are often displayed in zoos, sometimes together with Abedus herberti (also found together in the wild) and other aquatic beetles. The adult beetle has a length of 0.8–1.5 cm (0.31–0.59 in), with females slightly larger than males. The sunburst diving beetle has a black and streamlined carapace covered with bright yellow or golden spots. The male has a suction disk on each foreleg.
The sunburst diving beetle's distinctive yellow spots on a black background... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States | |
| 2 | Grand Canyon National Park | 🇺🇸 United States | |
| 3 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
Rare
Under 5% of wildlife watchers report a Sunburst Diving Beetle sighting in Cumbres de Monterrey National Park on a given day, based on 14 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 207th most-seen of the 431 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
January–February, May and October
In those months about 10% of wildlife watchers report a Sunburst Diving Beetle in Cumbres de Monterrey National Park on a given day, against under 5% in March–April, June–September and November–December, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Sunburst Diving Beetle sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 3
Of the 3 parks where we can rate Sunburst Diving Beetle sightings, Cumbres de Monterrey National Park ranks 3rd at under 5%. The best odds are in Saguaro National Park (United States, about 10%) and Grand Canyon National Park (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Sunburst Diving Beetle is recorded against all the insects logged in Cumbres de Monterrey National Park (14 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.
