Ochthebius viridis Peyron, 1858
This exclusively coastal species is generally common in south east England from Dorset to Lincolnshire but otherwise very local and generally scarce, it is absent from the east coast but occurs sporadically in the west as far north as the Hebrides and is very local around the coast of Southern Ireland. Two subspecies are recognized in the UK; ssp. viridis s.str. is widespread in the south whereas ssp. fallaciosus Ganglbauer, 1901 occurs in the west and in Ireland, and along the south coast of England they overlap, morphological differences are very slight and males need to be dissected for certain identification. In Europe the situation is confusing as the subspecies, along with various others, have often been considered distinct species and the concept of a superspecies has been used to describe a complex association of ‘species’ that occur throughout the region. Adults have been recorded from February to December and so it is likely that they overwinter, they peak in abundance during August but usually occur in numbers through the spring and summer. The usual habitat is brackish pools and salt marsh margins where adults may be observed on wet silty soil, although we found them in abundance during June 1916 Hampshire on damp soil under matted reed litter on extensive dry grassland bordering salt marsh.
Adults are tiny, consistently below 1.7mm, and entirely dark with an attractive metallic reflection, the forebody green and the elytra and abdomen bronze, all appendages pale brown. They may be distinguished by form of the labrum and the pronotum. Head transverse, roughly sculptured and finely punctured, with large convex eyes and smoothly curved labrum, palps only a little shorter than the antennae, the terminal segment shorter and much narrower than the penultimate segment. Antennae 9-segmented with a long scape and 5-segmented pubescent club. Pronotum transverse, broadest near obtuse anterior angles and narrowed to a gradual and smooth membrane covered emargination before near-perpendicular posterior angles, basal margin almost straight and apical margin curved. Surface without a median groove, with a shallow transverse impression in front of and behind the disc, and widely and shallowly impressed towards the lateral margins, very finely punctured throughout. Elytra broadly-oval, with sloping shoulders and evenly curved to separately rounded apical margins, striae complete and strongly punctured to the apex, interstices weakly convex and finely microsculptured. Legs long and slender, the tibiae only weakly broadened from the base and each with a series of stiff setae across the apex. Tarsi 4-segmented although often appearing 3-segmented due to the tiny basal segment, terminal segment long and weakly curved, claws smooth, the front claws with a weak basal tooth, the middle and hind claws without an obvious tooth at the base.