Ophonus ardosiacus (Lutshnik, 1922)
This species has a very wide and continuous Palaearctic distribution, from Portugal to Eastern Siberia, it is locally common across Southern Europe and Asia Minor, is present on most of the Mediterranean islands, Madeira, the Azores and northwest Africa, in Central Europe it is common across France and Switzerland but otherwise sporadic; it is very local and rare in Germany and is considered endangered in Austria, it is known from only a very few records in Poland and is absent from Denmark and the Baltic countries. The northern limit of the distribution is the UK where it is locally common in Central England north to Birmingham but otherwise very local and rare across the south although it tends to be frequent on the southern and eastern coasts from Dorset to the Wash, the majority of records are south of a line between the Humber and the Severn and beyond this there are isolated records from coastal South Wales, the Humber Estuary and Lancashire. Typical habitats are open grassland and agricultural borders on chalky or limestone soils and clay soils and cliffs in coastal areas, they often occur on ruderal sites among patchy vegetation and are probably most frequent in hilly areas; in Central Europe they occur mostly in warmer sites between 280 and 1200 m. Adults are present year-round; they overwinter among matted vegetation or in the soil and are only rarely recorded at this time, they are active between March and September and peak in abundance from May until August. They are diurnal and nocturnal although during the day they tend to remain hidden in all but the warmest periods, they are fully winged and disperse in the evening and at night when they may occur at light traps and sometimes in numbers. Reproduction occurs in late summer and early autumn and larvae develop through the winter to pupate in spring and early summer, both adults and larvae are phytophagous, feeding on seeds of a range of plants but especially wild carrot (Daucus carota L.), which adults climb during the evening and sit among the flowers chewing on the seeds. The larva is unknown but, typical of the genus, they probably collect seeds and provision subterranean chambers so that they can continue feeding through the winter. Searching suitable habitats by day or night is the best way to find adults as their large size and bright metallic colouration can hardly be missed, they often aggregate under debris during the day and so when feeding specimens are found at night it is usually worth searching the immediate area as many more are usually present.
Ophonus ardosiacus 1
Ophonus ardosiacus 2
Ophonus ardosiacus 3
Ophonus ardosiacus 4
9.5-11. mm. Entirely black or dark brown with a distinct metallic blue reflection, lateral pronotal margins and appendages reddish-brown, entire dorsal surface with fine brown pubescence. Head evenly convex and punctured between prominent eyes, each eye with a single setiferous puncture along the inner margin, antennae pubescent from the third segment. Pronotum transverse, broadest about the middle and evenly curved to widely rounded angles, surface punctured throughout, more densely and strongly so towards the margins, and with wide and shallow basal fovea. Elytra almost parallel-sided from rounded shoulders to a slight subapical constriction, basal margin straight and striae well-impressed but unpunctured, apices sharp and only slightly, if at all, divergent, interstices finely punctured throughout. Front and middle tarsi dilated in males. Readily identified by the combination of size, colour, pronotal shape and sharp, non-diverging elytral apices.