Pterostichus madidus (Fabricius, 1775)

Size: 14-18mm

Identification: This beetle is shiny and black with two different forms: one with rufous (brown) legs and (form concinnus (Sturm)) and one with black legs. It is your stereotypical 'black beetle' in appearance, but may be confused with other species. The best feature to use for identification is the fact that the hind angles of the pronotum are rounded. It is also wingless and the elytra are fused together.

Habitat: Woodlands, gardens and dry grasslands. Even found in houses.

Lifecycle: It is an autumn-breeding species and some adults overwinter to breed again the following summer. A very useful predator of slugs.

Similar species: P. madidus often co-exists with Pterostichus melanarius with which it can be confused. However, P. melanarius has sharp hind angles to the pronotum. Another similar species is Pterostichus aethiops, but this species has not been reocrded from Pembrokeshire and is smaller (11.5-13.5mm) with three rather one or two punctures on the elytra.

Field/Lab: This species can be identified in the field, as there are no other species of the same size with rounded hind angles to the pronotum in Pembrokeshire.

Status in Pembrokeshire: Common and widespread.

UK status: Common and widespread: the most frequently recorded ground beetle in the UK.