Cybister fimbriolatus
In 3 days ~30% in a week ~50%
Cybister fimbriolatus, the giant diving beetle, is a species of predaceous diving beetle in the family Dytiscidae. It is found in North America and the Neotropics. These beetles are active in summer and live in ponds or ditches, feeding on other aquatic arthropods. They are nocturnal but sometimes active during the day. For mating, the males have expanded front feet to help them grab hold of a female. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Padre Island National Seashore | 🇺🇸 United States | |
| 2 | Big Cypress National Preserve | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Dallas | 🇺🇸 United States | |
| 2 | Houston | 🇺🇸 United States | |
| 3 | Orlando | 🇺🇸 United States | |
| 4 | San Antonio | 🇺🇸 United States | |
| 5 | New York City | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Fringed Diving Beetle sighting in Big Cypress National Preserve on a given day, based on 10 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 116th most-seen of the 262 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
May to August
In those months about 20% of wildlife watchers report a Fringed Diving Beetle in Big Cypress National Preserve on a given day, against under 5% in April, September–October and December–February, the lowest months. Those are among Big Cypress National Preserve's wettest months, with about 200 mm of rain a month against 40 mm in March.
Between 10 pm and 1 am
Across all the parks we cover, that three-hour window holds the most Fringed Diving Beetle sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
Among the best
Of the 2 parks where we can rate Fringed Diving Beetle sightings, Big Cypress National Preserve ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Padre Island National Seashore (United States, about 10%).
Same family: Dytiscidae
The closest relatives of the Fringed Diving Beetle that you can see in Big Cypress National Preserve (family Dytiscidae, Predaceous Diving Beetles) are Neobidessus pullus (about 10%) and Hydaticus bimarginatus (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Fringed Diving Beetle is recorded against all the insects logged in Big Cypress National Preserve (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.
