Quedius scintillans (Gravenhorst, 1806)

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POLYPHAGA Emery, 1886

STAPHYLINOIDEA Latreille, 1802

STAPHYLINIDAE Latreille, 1802

STAPHYLININAE Latreille, 1802

STAPHYLININI Latreille, 1802

Quedius Stephens, 1829

Raphirus Stephens, 1829

This is a western Palaearctic species although it is sometimes quoted as transpalaearctic; the eastern extent of the distribution is parts of European Russia and northern parts of the Caucasus. In Europe it is locally common from lowlands to middle mountain altitudes from Spain to Greece in the south and north to the UK and some southern provinces of Sweden; it is present on many of the Mediterranean islands and is widespread north western Africa. In the UK it is locally common though rather sporadic across England and Wales though rather less so in the West Country, much more local and scarce further north to th3e Scottish Highlands and there are scattered records from Ireland. The species is rather eurytopic; occurring on various soils among decaying vegetation in a variety of damp but not wet habitats such as open grassland, agricultural land, wasteland, deciduous, coniferous and mixed woodland, pasture and even compost in domestic gardens. Adults are present year-round, they overwinter among litter or in tussocks but in general remain active through all but the coldest periods, they are active until late in the autumn and peak in abundance from March until May. Little is known of the biology but both adults and larvae are predatory and, from the phenology, it is likely that reproduction occurs in the spring and winter is passed in the adult stage. Adults are nocturnal, they mostly remain concealed but may occasionally be seen running on lawns or pathways etc., but the easiest way to see them is by sieving decayed litter and compost etc., where they may occur in numbers and usually along with plenty of other small staphs. In our local park we have found them through the spring and summer among piles of decaying pond refuse, under bark on fallen branches and under logs and, in the autumn, in numbers among decaying terrestrial bracket fungi.

Quedius scintillans 1

Quedius scintillans 1

Quedius scintillans 2

Quedius scintillans 2

4.5-6.0 mm. A rather broad species with a large head, weakly dilated elytra and tapering hind body. Head black with a variable metallic green or bronze reflection, pronotum and scutellum black or dark brown and metallic, as the head, elytra chestnut brown to reddish-brown, sometimes with a pale apical margin and usually less strongly metallic than the forebody, abdomen uniformly brown to dark brown.  Head proportionally large, with large eyes that occupy about two-thirds of the lateral margin and smoothly follow the outline, surface smoothly convex, with linear microsculpture and scattered small punctures, several setiferous punctures behind the eyes and a transverse series further forward consisting of a puncture beside each eye and a pair on the frons between these, anterior margin of the labrum with a distinct median notch. Antennae substantially pale but usually with at least some basal segments partially darker, basal segments elongate to quadrate, segments 8-10 quadrate to transverse. Pronotum smoothly rounded to a narrow apical margin, the posterior angles absent, surface with linear microsculpture, and a series of three setiferous punctures either side of the disc and others close to the lateral and basal margin. Scutellum large and triangular, impunctate and microsculptured as the pronotum. Elytra quadrate or nearly so, without striae, densely and randomly punctured and with conspicuous pale pubescence throughout. Abdomen brown or pale brown, the apical margin of the tergites often narrowly pale, iridescent, finely wrinkled and with conspicuous and uniform pale pubescence. Legs pale to dark brown but always with the inner margins of the middle and hind tibiae metallic black. Apical margin of the eighth abdominal sternite excised in males. Distinguished from closely similar species by the uniformly oriented abdominal pubescence and by the asymmetric form of the aedeagus.