Lamprinodes saginatus (Gravenhorst, 1806)
This is a mostly central and northern European species although there are records from North Africa; it extends from France to Northern Italy and the Black sea in the south and to the UK, Belgium and the Baltic countries to the north where it is widespread across southern Norway, Sweden and Finland; it tends to be rare in central and southern regions and more common, though very local in the north. In the UK it is widespread though very local and generally scarce throughout England, Wales and Scotland and there are several older records from Ireland (Wexford, Monaghan and ‘near Dublin’. The species typically inhabits open and dry heathland and moorland while in Northern Europe, including the UK, it also occurs in open deciduous and coniferous woodland. Adults are present year-round; they remain active in all but the coldest winter spells and peak in abundance from April until June. Little is known of the biology but adults are often associated with various ants; in the UK possibly with Lasius flavus Fab,) but more generally with L. niger (L.) as well as other species of Lasius Fab., Formica L. and Myrmica Lat. They may be found by sieving or extracting samples of moss or tussocks etc from open situations, especially on light or sandy soils, or leaf-litter near to ant colonies, they sometimes occur under stones or debris in dry situations and in suitably-placed pitfall traps.
3.4-5.0 mm Elongate and fusiform, head and pronotum glabrous, elytra and abdomen with extremely fine pubescence, head black, pronotum brown, elytra brown, often with the scutellary region darker, abdomen black, usually with the tergites pale apically, appendages pale brown. Head smooth and weakly convex between transverse eyes that follow the outline, temples small and curved, clypeus transversely impressed before a smoothly rounded apical margin, apical maxillary palpomere short and tapering from the base. Antennae inserted anteriorly about the exterior margin of the mandibles, 11-segmented and long; reaching to the pronotal base, laterally compressed and gradually expanded from the fifth segment; segments eight to ten distinctly transverse. Pronotum transverse, broadest in front of rounded posterior angles and smoothly narrowed to obscure anterior angles, basal margin weakly sinuate, surface evenly convex, without structure, lateral margins with a few very fine setae. Elytra transverse, weakly curved and very finely bordered from rounded shoulders to rounded angles and recurved apical margins, surface smoothly convex and finely punctured, sutural margin not raised, lateral margin with seven or eight long outstanding setae. Abdominal borders raised and with numerous outstanding setae, tergites finely punctured throughout, in some lights appearing quite strongly iridescent. Front and middle tibiae with two or three strong external spines and paired apical spurs, hind tibiae with paired spurs on the external apical angle but without spines along the external margin. Tarsi with five simple segments, the fourth hind tarsomere distinct and only slightly shorter than the third segment.
Very similar to Tachyporus, in which it was formerly included, but distinguished by the laterally compressed antennae and the distinct fourth segment of the hind tarsus; in Tachyporus the antennae are not (or only very weakly) compressed, and the fourth segment of the hind tarsi is diminutive.