Eutheia linearis Mulsant & Rey, 1861
This species is known mostly from central and northern Europe although there are records from Northern Russia and the Eastern Palaearctic region; with the exception of central parts of Fennoscandia, where it is sometimes locally common, it is generally very local and rare and there are only a few records from most countries, it is recorded from Germany to Hungary and Romania and north to the UK and the Baltic countries where it reaches the Arctic Circle in Sweden. The present UK status is uncertain; there are older records from Sherwood Forest, Berkshire and the New Forest and unconfirmed records from elsewhere in England, and it is known to be present on Inchcailloch, a tiny (about 0.2 square miles) nature reserve island on the inlet of Loch Lomond in Scotland. Adults have been found under damaged or dead bark or among moist and decaying wood in old established woodland, in the UK mostly on oak (Quercus L.) but in Northern Europe on a wide range of both broadleaf and coniferous trees including oaks, Aspen (Populus tremula L.), birch (Betula L.), alder (Alnus Mill.) and spruce (Picea Mill.), often in association with or even in the nests of various ants of the genera Lasius Fab. and Formica L., but they are not restricted to this habitat as they also occur among moss or litter near old stumps etc., and the Inchcailloch specimens were found among rotting vegetation on grassland. Little is known of the biology but in Northern Europe the majority of records are from May and June and from August, September and October, and they almost always appear as single specimens.
Eutheia linearis 1
© Lech Borowiec http://www.cassidae.uni.wroc.pl/Colpolon/index.htm
Eutheia linearis 2
© U.Schmidt www.kaefer-der-welt.de
1.15-1.35 mm. Elongate, discontinuous in outline and flattened or only weakly convex, dorsal surface with rather dense pale pubescence throughout, entirely dark brown or with the elytra paler towards the apex, antennae brown with darker clubs, legs entirely brown. Head weakly convex and finely punctured between large and convex eyes that occupy most of the lateral margin, temples short and converging to a strongly and widely recurved basal margin. Antennae 11-segmented; in males distinctly clubbed with segments 9 & 10 transverse and distinctly broader than segment 8, in females with segments 5-7 quadrate and then gradually thickened towards the apex. Pronotum transverse, broadest about the middle and narrowed to a rounded anterior margin and distinct, perpendicular or slightly obtuse posterior angles, lateral margin bordered, this visible towards the base from above, surface finely punctured throughout and with five fovea in front of an almost straight basal margin. Elytra weakly curved laterally from sloping shoulders to truncate apical margins which leave the abdomen partly exposed, surface without striae, randomly and finely (though stronger than those on the pronotum) punctured throughout, and longitudinally depressed below the humeri. Legs long and slender with the front femora shorter and thicker than the middle and hind femora, tibiae only weakly thickened from the base, finely pubescent but without apical spurs. Tarsi with five simple segments in both sexes. Males may be distinguished by their larger and more convex eyes and less distinctly clubbed antennae. Aedeagus distinct; parameres almost straight and the median lobe strongly narrowed before tapering to an acute apex. Very similar to E. scydmaenoides Stephens, 1830 but flatter and with the pronotum less strongly punctured than the elytra, in that species the body is more convex and the pronotum is more strongly punctured than the elytra. Females need to be compared with named material in order to appreciate they flatter form but even so they may not be distinguishable.