Ridged Violet Ground Beetle

Fast Facts

Latin name: Carabus problematicus

Notable feature: A large and shiny black beetle with an extensive violet sheen across its top surface- most notably across the top of its thorax (known as the pronotum) and edges of the fused wing cases (the elytra). The wing cases of this beetle have a textured and rough looking appearance.

Conservation Status: Not Evaluated

Where in the UK: A very widespread species occurring commonly across the UK

Ridged Violet Ground Beetle (Carabus problematicus) © Roger Key

The Ridged Violet Ground Beetle (Carabus problematicus) is a large, native, shiny black beetle with a violet sheen, especially around the edges of the fused wing cases (the elytra) and the thorax (the area between the head and abdomen known as the pronotum).

The elytra have a distinct textured pattern making them appear rough looking, unlike the more common Violet Ground Beetle (Carabus violaceus), which has a smoother and almost matt appearance to the elytra, as well as a more convex body shape.

Although the UK population has been declining in recent decades, this species is still common across the UK. The Ridged Violet Ground Beetle is less common than the Violet Ground Beetle; like this species, both are incapable of flight.

The Ridged Violet Ground Beetle can be found in a variety of habitats including woodland, grassland and heathland but rarely gardens.

  • Size: 20-28mm in length
  • Life span: Over most of the UK the life cycle is annual but in northern areas and at higher altitudes it can take two years.
  • Diet: Adults and larvae predate on insects, slugs, snails and worms on the ground amongst leaf litter and under logs.
  • Reproduction: Adult beetles usually mate in spring and early summer. Eggs are laid in the soil from late spring and larvae develop through the summer, with new adults emerging in the autumn. Some, however, will mate and lay eggs during autumn that will develop over winter and hatch during the spring. Adults can survive the winter in leaf litter and in habitat piles.
  • When to see: Adults are nocturnal and can be seen throughout the year.  They become more active from March or April as mating occurs mostly in the spring and early summer following a period of feeding and egg laying in late spring.
  • Population Trend: Declining
  • Threats: Reduction and loss of habitat; woodland, grassland and heathland.  As a flightless beetle they are significantly affected by habitat destruction and fragmentation.
  • Fun Fact: The Ridged Violet Ground Beetle belongs to the large caribidae family group (362 species on the 2012 edition of the British list).  With such a large group – there are more carabids on the British list than there are breeding bird species!

How you can help: 

Buglife is working to increase awareness of invertebrates and the Ridged Violet Ground Beetle through specific projects and campaigns, but we need your help!

Join a recording scheme and log your finds – send any records/sightings to the Ground Beetle Recording Scheme or download the iRecord app and get recording!

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