Tachinus rufipes (Linnaeus, 1758)
This generally common species occurs from lowland to low mountain altitudes throughout Mediterranean Africa and Europe north to Scandinavia and east through Russia and Asia Minor to Kazakhstan and Siberia; with the exception of the West Country and Shetland it locally common or abundant throughout the UK, and in the Nearctic region it is widespread in northern Canada. Adults occur year-round; they become active in early spring and peak in abundance during March and April, then again from July to September, and remain common until they enter the soil beneath leaf-litter and tussocks etc. to overwinter. They are generally associated with decaying organic material in a wide range of moist but not wet situations e.g. compost, dung, leaf-litter and fungi; they may be especially common among horse dung on woodland bridle paths through the summer, although they are usually infrequent at dung on cattle pasture, and among large decaying terrestrial bracket fungi in the autumn, more generally they occur under logs or debris and matted vegetation on damp wooded margins, grassland and parkland and will occasionally arrive at carrion. Both adults and larvae are predatory, feeding on eggs and larvae of other insects etc. and on aphids in various situations; on the continent they are often among the most common staphs in lowland wheat growing areas in the summer. Adults are readily sampled by searching in likely situations, they occasionally occur when sweeping grass etc. in the summer and are frequent in extraction samples through the winter, they fly well and so may occur in any suitable situation.
The dark colour and fusiform shape will suggest this species in the field but for critical work specimens should be taken for examination as there are several closely similar UK species. 4.5-6.5mm, characteristically elongate-oval, this becomes obvious even in specimens with the abdomen retracted, and dark with the pronotal and elytral margins narrowly pale, lateral margins of the pronotum without stiff setae; only the fourth and fifth abdominal segments with
a single long seta at the posterior angles. Head finely transversely microsculptured and punctured, with small convex eyes and long temples that are generally hidden within the prothorax. Antennae inserted laterally outside the base of the mandibles, segments elongate at base then becoming shorter apically, maxillary palps long and slender with the terminal segment longer than the penultimate. Pronotum transverse, broadest in posterior half and evenly curved and distinctly bordered laterally; dark with posterior angles variously pale, this pale colour may continue narrowly along the basal and lateral margins but does not reach the anterior angles. Surface finely punctured and with wavy transverse microsculpture which is distinct at X40. Elytra quadrate to slightly transverse, longer than the pronotum, finely punctured and with widely transverse microsculpture (X40), without striae or a raised sutural margin but strongly bordered laterally, entirely dark or obscurely pale inside the humeral angles. Abdomen evenly tapering and strongly bordered, finely pubescent and with dense transverse microsculpture (X40); terminal segments sexually dimorphic and characteristic of the species. Legs long and robust; pro-tibiae with 3 rows of spines and a strong apical spur, meso- and metatibiae with 4 groups of spines and strong apical spurs, tarsi 5-5-5, basal segments dilated in the male.