Pterostichus quadrifoveolatus Letzner, 1852
A Western Palaearctic species extending east to the Caucasus; in widespread but very local and for the most part scarce, from Northern Spain to Italy and Ukraine in the south and north to the UK, Denmark and the Baltic countries where it reaches into southern Provinces of Norway, Sweden and Finland. It was first discovered in the UK in the early 20th Century and has now become widespread though very local throughout England and Southern Scotland but remains very rare and mostly coastal in the West Country and Wales; it has not been recorded from Ireland. In the UK the species occurs on dry lowland heaths and in open Pine woodland, especially on light or sandy or peaty soils. On continent it frequents similar habitats, in northern areas especially in open coniferous woodland and especially under charred logs and charcoal in recently burned areas to which it often seems to be particularly attracted, the species is very resistant to dehydration and generally prefers warmer areas, occurring from lowland to upland and lower mountain altitudes. In many areas it seems to prefer more acidic substrates with pH values between 3.3 and 5.5. The species flies well and has strong dispersal ability and so may be quick to find new sites; in Northern Europe generally the greatest abundance occurs in open conifer forests and drops as density of trees increases, it only occasionally occurs on open heaths and never in deciduous woodland. Adults occur year-round; they overwinter under logs or bark and are active from March until October, peaking in abundance during May and often diapausing in the summer. Reproduction occurs in the spring and females oviposit in the soil, each producing up to 300 eggs in a season and many going on to breed a second time after overwintering. It is likely that the species is univoltine but under laboratory conditions females were able to reproduce three times within about six months. New generation adults occur in the autumn; they enter a short but intense period of flight before overwintering and seem never to fly again. Adults are mainly nocturnal and so may be found under bark or logs etc during the day, they usually occur as single specimens or in pairs although pitfall traps may produce them in numbers.
9.5-11.5 mm. A large and shiny black species, sometimes with a faint metallic lustre, with a heavily sculptured pronotum, distinctly punctured elytra and long robust legs. Head rather flat between large and prominent eyes, strongly punctured inside and/or behind the eyes, otherwise very finely punctured, each side with two supra-orbital setiferous punctures, frontal furrows usually weakly impressed. Antennae relatively short, with the basal segment distinctly shorter and usually wider than the third segment. Pronotum broadest in front of the middle and strongly sinuate before sharp posterior angles, basal margin angled obliquely forward laterally, explanate margin narrow and only slightly wider towards the base, basal fovea (one on each side) long, linear and usually punctured around the base. Elytra only weakly expanded from rounded shoulders to a weak subapical constriction, striae well-impressed and at most only finely punctured, interstices flat or weakly convex, the third with three foveate punctures or, very occasionally, an extra puncture on one or both sides. Epipleura crossed before the apex. Legs long and robust, entirely black or with tibiae and tarsi dark brown, front tibiae strongly expanded beyond the antennal-cleaning notch. Both sexes are equally shiny but males are easily identified by their dilated front tarsi.