Adults are commonly about 15–20 mm long.
Fine-art photographic collection
Pterostichus madidus
A powerful nocturnal ground hunter found in two striking leg-colour forms within the same species.
About this species
Black Clock Beetle
Pterostichus madidus(Fabricius, 1775)
Information reviewed15 July 2026
Pterostichus madidus is a large common ground beetle of gardens, woodland and farmland. It hides by day and hunts at night, attacking slugs, caterpillars and other ground-dwelling invertebrates while also taking some seeds and plant matter.
Taxonomy
Animalia · Arthropoda · Insecta · Coleoptera · Carabidae · Pterostichus
Accepted taxon. · checked 2026-07-15
western and central EuropeBroad range and selected reference localities — not a complete occurrence map.
western and central Europe
Gardens, woodland, hedgerows, grassland and farmland beneath stones, logs and litter.
Primarily nocturnal; shelters in dark humid retreats during the day.
Slugs, caterpillars and other invertebrates, plus some seeds and plant material.
Solitary.
What makes this species remarkable?
Red-legged and completely black-legged adults can occur in the same population, creating two immediately different-looking forms without representing separate species.
Both adults and larvae are active predators, and a large adult can tackle soft-bodied prey such as slugs, leatherjackets and caterpillars.
The beetle spends daylight compressed beneath stones or wood, then emerges after dark as one of the garden’s largest roaming invertebrate hunters.