Ophonus rufibarbis (Fabricius, 1792)
This very widespread western Palaearctic species is locally common throughout Europe and North Africa, extending north to southern Fennoscandia and the UK and east through Asia Minor and Russia to Central Asia; it has also become established in the United States since its accidental introduction in the 1950s. Here it is common throughout southern England and the midlands though more local and scattered in western and northern areas and rare and mostly coastal in Scotland north to the highlands, and it is generally our commonest member of the genus. Adults occur in a wide range of fairly dry habitats including parkland, arable land, gardens and disturbed sites generally, grassland, scrubland and open deciduous woodland, they may also occur on drier areas of river margins and estuaries and, at least on the continent, in salt marshes; in general they prefer quite heavy clay soil with a layer of humus and plenty of vegetation. Adults are present year-round, peaking in late spring, and active over a very long season; they are nocturnal, spending the day in tussocks or under debris, and roaming among vegetation or on pathways as soon as the light fades. At least some specimens fly well and are occasionally attracted to light although flight muscle and wing development has been found to vary in continental specimens. They are predatory but also known to feed on umbel seeds and foliage. Mating occurs in the spring and larvae develop through the summer, new generation adults may occur in the autumn but, at least on the continent, larvae are known to overwinter. Adults are easily recorded by pitfall trapping or surveying the carabids that are numerous on pathways through parkland or grassland at night.
6.5-9.5mm. Entire insect shiny pale to dark brown, usually with the elytra and sometimes with the head darker. Head sparsely punctured and pubescent, with a single setiferous puncture beside each convex and protruding eye. Antennae pubescent from the third segment, maxillary palps well-developed the terminal segment about as long as the penultimate, mandibles sharp at apex. Pronotum transverse; about 3:2 (measure carefully), strongly sinuate laterally before sharp and perpendicular posterior angles, each side with two long setae among shorter setae in the anterior half, basal margin not bordered (this must be looked at very carefully). Pronotum more sparsely punctured on the disc than laterally. Elytra broadly rounded to the apex, basal border from the first stria to the shoulder straight, shoulder usually with a small but distinct tooth. All striae, including a scutellary striole which may be interrupted, impunctate, interstices with two or three rows of fine punctures although these vary and are generally confused in places. Elytra finely pubescent throughout and with microsculpture (X20) which give them a dull appearance compared with the forebody. Legs long and robust, middle and hind tibiae with two apical spurs, the longer of which is as long as the first tarsomere, anterior tibiae with a deep antenna-cleaning notch and a strong apical spur. Basal segments of anterior and middle tarsi dilated in the male. Male genitalia distinctive; gradually tapering to the apex and with the ventral surface virtually straight, the apex may be slightly curved but it is not expanded or modified