Acilius sulcatus
In 3 days ~10% in a week ~20%
Acilius sulcatus, known as the lesser diving beetle, is a species of water beetle in the family Dytiscidae. It is fairly large (14.4 – 18.2 mm), with color variation shown throughout its range. Typically it is yellow and black.
A. sulcatus has a worldwide distribution but is found primarily in North Western Europe. A. sulcatus is known throughout Europe as the lesser diving beetle, a common name shared with many other aquatic beetles in the family Dytiscidae.
Temporary and permanent water bodies. A. sulcatas shows a generalist response to habitat choice, living in bogs, ponds, streams, etc. As A. sulcatus is able to fly, it is not restricted to a single body of water. A. sulcatus is found in water bodies with high and low levels of vegetation, showing no preference between the two. They dominate in water bodies without any fish predators and are used as a primary indicator of predator presence.
A. sulcatus is found over a large range and is not thought to face any pressures on the continuity of the species; as such, the beetle has not been evaluated by the IUCN. A unique morph is, however, recognized in the Akfadou... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Novosibirsk | 🇷🇺 Russia | |
| 2 | Berlin | 🇩🇪 Germany | |
| 3 | London | 🇬🇧 United Kingdom | |
| 4 | Vienna | 🇦🇹 Austria | |
| 5 | Moscow | 🇷🇺 Russia |
Rare
Under 5% of wildlife watchers report a Lesser Diving-Beetle sighting in Vienna on a given day, based on 7 verified sightings from GBIF citizen-science data. It is the 1178th most-seen of the 1406 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Lesser Diving-Beetle in Vienna on a given day, so our monthly data shows no clear season.
Between 5 and 8 pm
Across all the parks we cover, that three-hour window holds the most Lesser Diving-Beetle sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
Among the best
Of the 5 cities where we can rate Lesser Diving-Beetle sightings, Vienna ranks 4th at under 5%, level with the leaders once rounded. The best odds are in Novosibirsk (Russia, under 5%), Berlin (Germany, under 5%) and London (United Kingdom, under 5%).
GBIF citizen-science records
It is estimated from how often the Lesser Diving-Beetle is recorded against all the insects logged in Vienna (7 verified sightings), 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.
