Philonthus intermedius (Lacordaire, 1835)
This Western Palaearctic species occurs throughout Europe from Portugal north to the UK and southern Fennoscandia; it extends east through Russia and Asia Minor as far as Turkmenistan and is widespread across North Africa. It is generally common in the south but becomes more sporadic and local further north and is generally rare in Germany, Poland and the Baltic countries; in the UK it is locally common across central and south east England, mostly coastal in Wales and there are a few scattered records north to the Scottish Highlands and the Western Isles. Adults are present year-round and are active over a long season from early spring, they occur among decaying vegetation, fungi and carrion etc. but are most often encountered in dung, frequently at cattle dung but also in other types including fox and badger. Across much of northern Europe it is associated with woodlands but here it is typical of dung pasture although adults may occur in a wide range of habitats e.g. compost in domestic gardens during the summer when they frequently fly in warm weather. Little is known of the biology but adults are common in the spring and through the summer, and given its lifestyle, it is very probable the breeding occurs in the spring and that predaceous larvae develop rapidly in spring and early summer. Adults occur among suitable extraction samples through the winter and, despite the species being local, may be very common on dung pasture in the spring where they may be sampled in flight or by using pitfall or dung-baited traps.
8-11 mm. With a little experience this species is easily recognized in the field; the bright metallic colouration, lack of pronotal punctures and the form of the head and antennae are distinctive, the only confusion might be with P. laminatus (Creutzer, 1799). Body black and shiny, head and pronotum bright metallic green or bluish green, elytra and scutellum dark metallic green and usually distinctly contrasting with the forebody, abdomen and appendages black. Head quadrangular and distinctly transverse in both sexes (width to length ratio 1.3-1.5), surface evenly convex, very finely punctured and with scattered larger punctures towards the base and between the eyes, temples rounded and shorter than the weakly convex eyes, in most specimens with a distinct microsculpture towards the base and on the neck. In series males will be seen to have larger heads and enlarged mandibles. Antennae inserted anteriorly within the base of the mandibles, three basal segments long and glabrous apart from outstanding setae, from segment four progressively shorter and with dense and fine pubescence, segments seven to ten distinctly transverse. Pronotum more-or-less straight from a rounded basal margin to distinct anterior angles, surface smoothly convex, with scattered tiny punctures and traces of microsculpture towards the margins, dorsal series of setiferous punctures missing, lateral margin with a single large puncture about the middle and several smaller punctures towards the base and apex. Scutellum large, triangular and finely punctured and pubescent. Elytra quadrate or slightly transverse and without striae, punctures coarse and moderately dense; in placed forming transverse series and separated by up to five puncture diameters, lateral margins with two long setae, one subhumeral and one median, surface pubescence dark. Abdomen rounded laterally, not strongly tapering, coarsely and moderately densely punctured throughout and basal tergites with two fine lines across the base. Legs long and robust, all tibiae with numerous stiff setae along the outer margin and long apical spurs. Basal segments of front tarsi expanded, a little more so in males, basal segment of hind tarsi longer than the terminal segment and about as long as 2-5 combined.