Oxytelus laqueatus (Marsham, 1802)
This is a very widespread Palaearctic species occurring from North Africa to the far north of Scandinavia and east through Siberia and Mongolia, it is locally abundant in northern areas but through most of the southern parts of its range occurs mostly in mountainous regions; in the UK it is generally common throughout England, Wales and Scotland and is usually among the most abundant beetles occurring at dung. Following introductions the species is now established throughout the New World, occurring to far northern latitudes. Adults occur year-round, becoming active early in the spring and generally abundant by late April or May; the species is strongly associated with herbivore dung, in the UK mostly horse and cattle dung, but a wide range of dung are utilized e.g. above the Arctic Circle in Scandinavia they breed in reindeer dung, and they also occur among decaying vegetation; litter and compost, and adults occasionally occur at carrion. Adult populations peak in early summer when they are easily observed by disturbing dung and waiting for them to fly in and alight, during hot afternoon sunshine they may arrive in large numbers and they continue flying into the evening when they may be swept in flight or attracted to light or sap in large numbers. They remain common into the autumn, which may suggest more than one generation each year, when they enter the ground or remain below dried dung pats etc. to overwinter. Some idea of the abundance of this species, usually along with other oxyteline staphs, can be gained by immersing fairly fresh dung samples in water, on several occasions during May and June we have produced hundreds of adults by this method.
Adults can be recognized in the field by the relatively large size and distinctly bicoloured appearance but there are several very similar species; the following description will serve to distinguish the present species. 3.8-4.5mm. Elongate and rather parallel-sided, entirely dark but for the red or yellow elytra and pale legs. The sexes are distinguished by the form of the head; in the male the temples are widened before the basal constriction and the anterior margin of the clypeus is toothed, in females the temples are broadest at the posterior margin of the eye and evenly curved to the neck, and the anterior margin of the clypeus is obtusely angled laterally. Head shiny, lacking distinct microsculpture, and moderately strongly punctured; concave or flat anteriorly and distinctly impressed either side of the vertex, eyes convex and prominent; in the female about as long as the temples, in the closely similar O. Piceus (Linnaeus, 1767) they are much longer than the temples. Antennae short and bicoloured; segments 1-4 pale, 5-11 dark and more strongly pubescent, the basal segment long and constricted before the apex, a character present in only one other UK species; O. piceus. Pronotum transverse, shiny and punctured a little more strongly than the head, with smooth lateral margins and several irregular longitudinal furrows either side on the disc. Scutellum rhombiform but usually hidden or partly hidden beneath the posterior pronotal margin. Elytra transverse and broadest behind the middle, quite strongly and often confluently punctured, especially in the male, so appearing to varying degrees irregularly longitudinally striate. Transverse line at the base of abdominal segments 1-6 angled or curved posteriorly before the raised lateral margin. In combination with the characters mentioned above, males are distinguished by the form of the posterior margin of the eighth sternite; curved either side of a truncate median projection. Legs entirely pale; pro- and meso- tibiae emarginate before the apex and with dense, fine spines along the outer margin. Tarsi 3-segmented with the terminal segment very long.