Haeterius ferrugineus

Diagnosis
Among the European fauna adults are distinct and should not be confused with any other species. 1.3-2.0mm. Very broadly-oval, almost continuous in outline and entirely brown to reddish-brown in colour, dorsal surface smooth and rather shiny, pronotum and elytra with sparse erect pale setae. Head widely transverse when viewed from above, weakly convex, smooth and with small transverse eyes, antennae 9-segmented, the basal segment greatly expanded internally, 2-8 gradually widened and the terminal segment forming a large and truncate club. Pronotum very transverse and widest at perpendicular posterior angles, anterior angles rounded and weakly produced, disc evenly convex between paired sub-lateral striae and there is a variable basal depression towards the lateral margin. Elytra transverse and evenly rounded to a continuous apical margin, each with a fine and usually abbreviated sub-humeral stria and three or four striae across the disc that extend almost to the apex, the erect setae arranged in longitudinal rows on or near these striae. Pygidium and propygidium smooth and shiny. Legs long and robust; femora narrow and simple, tibiae flattened and broad; straight internally and strongly angled externally. Tarsi 5-segmented and simple.

Distribution
Europe & Northern Asia (excluding China)

Biology
Ant hosts: Formica fusca, Formica cinerea, Formica rufa