Thermonectus marmoratus
In 3 days ~20% in a week ~40%
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 |
With luck
About 10% of wildlife watchers report a Sunburst Diving Beetle sighting in Grand Canyon National Park on a given day, based on 10 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 68th most-seen of the 143 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
April to October
In those months about 10% of wildlife watchers report a Sunburst Diving Beetle in Grand Canyon National Park on a given day, against under 5% in November to March, 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.
Among the best
Of the 3 parks where we can rate Sunburst Diving Beetle sightings, Grand Canyon 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 order: Coleoptera
The closest relatives of the Sunburst Diving Beetle that you can see in Grand Canyon National Park (order Coleoptera, Beetles) are Convergent Lady Beetle (about 20%), Obscure Darkling Beetle (about 20%) and Seven-Spotted Lady Beetle (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Sunburst Diving Beetle is recorded against all the insects logged in Grand Canyon National Park (10 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.
