Acilius mediatus
In 3 days ~10% in a week ~30%
Acilius mediatus is a species of predaceous diving beetle in the family Dytiscidae. It is found in North America. This species lives in creeks, ponds and ditches, occasionally with silt-laden streams, and are best seen during spring and summer. Prey is composed of other aquatic arthropods they can tackle. Males have expanded front feet with clumps of hairs used to grab hold of a female for mating. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Shenandoah National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Washington | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report an Acilius mediatus sighting in Shenandoah National Park on a given day, based on 6 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 571st most-seen of the 723 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.
April to June
In those months about 10% of wildlife watchers report an Acilius mediatus in Shenandoah National Park on a given day, against under 5% in July to March, the lowest months.
Between 10 am and 1 pm
Across all the parks we cover, that three-hour window holds the most Acilius mediatus sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Only Shenandoah National Park, in our data
Shenandoah National Park is the only park on Wallace's Line with enough records to rate Acilius mediatus sightings: under 5% of wildlife watchers there report one on a given day.
Same order: Coleoptera
The closest relatives of the Acilius mediatus that you can see in Shenandoah National Park (order Coleoptera, Beetles) are Asian Lady Beetle (about 30%), Larger Elm Leaf Beetle (about 30%) 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 Acilius mediatus is recorded against all the insects logged in Shenandoah 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.
