Pterostichus madidus
In 3 days ~20% in a week ~50%
Pterostichus madidus, commonly known as the black clock beetle, is a species of ground beetle native to Europe. The black clock beetle typically grows between 14–20mm in length, and is black in colouration, with legs that are usually red, reddish brown, or black. It can be found most abundantly in summer, and breeds during the autumn. It is commonly found in gardens, grasslands, and dry woodland, under stones, in grass, or in loose bark.
In the United Kingdom, this beetle is commonly known as the rain beetle as they tend to appear when rain is imminent. There is an old superstition that should you step on one or kill one, it will cause it to rain. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Snowdonia National Park | 🇬🇧 United Kingdom | |
| 2 | Cairngorms National Park | 🇬🇧 United Kingdom | |
| 3 | Pyrénées National Park | 🇫🇷 France | |
| 4 | Cévennes National Park | 🇫🇷 France |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Birmingham | 🇬🇧 United Kingdom | |
| 2 | Manchester | 🇬🇧 United Kingdom | |
| 3 | London | 🇬🇧 United Kingdom | |
| 4 | Liverpool | 🇬🇧 United Kingdom | |
| 5 | Dublin | 🇮🇪 Ireland | |
| 6 | Leeds | 🇬🇧 United Kingdom |
With luck
About 10% of wildlife watchers report a Black Clock sighting in Snowdonia National Park on a given day, based on 9 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 227th most-seen of the 387 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 50%, if each day is a fresh chance.
March and May–September
In those months about 10% of wildlife watchers report a Black Clock in Snowdonia National Park on a given day, against under 5% in April and October–February, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Black Clock sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 4 parks where we can rate Black Clock sightings, Snowdonia National Park has the highest daily chance: about 10%. Next come Cairngorms National Park (United Kingdom, about 10%) and Pyrénées National Park (France, about 10%).
GBIF citizen-science records
It is estimated from how often the Black Clock is recorded against all the insects logged in Snowdonia National Park (9 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.
