Coprophilus striatulus (Fabricius, 1792)
This is a mostly central and northern European species, it is locally common from lowland to lower mountain altitude from France to Ukraine and western Russia, it extends south into Italy but is absent from the Balkans and the Near East, to the north it reaches southern Fennoscandia and the UK and it is now established in eastern North America and Canada following accidental introductions during the 1980s. In the UK it is very local and scarce; the majority of records are from East Anglia where it seems to be common around the north Norfolk coast, there are records from the southeast below London but it is otherwise absent from the south, and it is local across the midlands but beyond this it is very sporadic and rare across Wales and further north to the Scottish borders. In the UK it is (nowadays) typically associated with wetland habitats and often occurs beside streams and reed beds but in Europe it is more eurytopic, occurring under logs and loose bark in wooded areas, parkland and gardens and is often abundant among straw and decaying root crops discarded in fields, it is also synanthropic, occurring in cellars and outbuildings and adults are also recorded at sap. Adults are active over a short season from April until June and have been recorded much less frequently through the autumn and winter, during the spring they may be found running in the open or on rocks and debris and they occasionally swarm and disperse by flight in the afternoon or evening. They are thought to breed in early summer as larvae have been found in August and they are likely to overwinter exclusively as adults. Sampling should be done among decaying organic material in marginal wetland situations, by extractions or pitfall trapping, but they are also likely to occur in other situations e.g. Fowler (1888) quotes them ‘in haystacks and vegetable refuse and hotbeds’ and records them from Lincolnshire as ‘common on pavements in early spring, running in the sun, but not found later in the year’ and they have been recorded in Europe from beneath carrion and cow dung and from a mole’s nest in the winter.
The large size and very distinctive appearance should easily distinguish this species from all other UK staphs. 6.5-7.0mm. Body substantially shiny black, often with narrow reddish margins to the pronotum, elytra and abdominal tergites, antennae and legs dark brown, tarsi red. Head and pronotum with scattered long and curved marginal setae. Head quadrate or nearly so, with small convex eyes and straight or weakly curved temples, surface closely and quite strongly punctured throughout and with a broad U-shaped ridge extending from above the antennal insertions to the posterior margin of the eyes. Antennae inserted laterally in front of the eyes, segments 1-3 elongate, 4-10 quadrate or nearly so and the terminal segment elongate-oval. Pronotum quadrate, broadest in the apical half and narrowed to distinct anterior and posterior angles, lateral margins crenulate throughout, surface with an broad longitudinal impression that does not extend to the base and a variable oblique impression either side before the base, punctures a little larger and more widely spaced than those on the head. Scutellum large, triangular and strongly and densely punctured. Elytra quadrate with rounded shoulders and converging apical margins, surface roughly punctured and wrinkled, with irregular longitudinal impressions that begin behind the base and end before the apical margin. Elytra very strongly bordered laterally, the tergites smooth across the base and punctured and pubescent to the apex, these become weaker and sparser on the apical segments. All tibiae with stiff spines along the outer margin which become larger towards the apices and a small but obvious spur on the inner apical angle. Tarsi 5-segmented, the basal segments short and lobed ventrally and the terminal segment very long. Claws smoothly curved and with a strong basal tooth.