Stenus solutus Erichson, 1840

Widespread and locally common throughout Europe from France to western Russia and Asia Minor, this species is locally common in central regions but more sporadic in the north; it is generally rare in Denmark and Poland, although recent data suggests it may be expanding, but more frequent in southern Sweden and Norway, which represent the northern limit of its range. It is generally common across Wales and England as far north as south Yorkshire and there are a few widely scattered records from Ireland but it is largely absent from northern England and Scotland. An exclusively wetland species, typical habitats include densely-vegetated margins of lakes, ponds and rivers, marshes, mires and permanently damp grassland with sedges and other marginal plants. Adults are present year-round, they overwinter among litter or in stems of reeds (Phragmites Adans,) or rushes (Typha L.) etc. and are active from early spring until late in the summer, they spend much of their time on the ground predating springtails etc. but during warm spells they climb stems and foliage and may even roam exposed wet soils away from vegetation. The species is easily sampled by sweeping foliage or pitfall trapping but following heavy rain they sometimes occur in numbers among accumulated refuse, they can move easily on the water surface but they do not linger, instead they move quickly towards emergent vegetation along the shore. Adults will need to be examined carefully for certain identification as the superficially similar S. cicindeloides (Schaller, 1783) is common in the same habitats.

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​5-7mm. Body rather dull black, finely and densely punctured and with pale pubescence, legs extensively yellow with the femora, tibiae and tarsi variously darkened, antennae yellow but darkened from about the fifth segment. Head transverse, at most as wide as the elytra, with large convex eyes that occupy the entire lateral margin and two shallow longitudinal depressions which leave the median area slightly raised. Pronotum quadrate and distinctly narrower than the head and elytra, broadest about the middle and evenly curved to distinct angles, anterior and posterior margins almost straight, the surface evenly convex and without, or with only a very weak, median longitudinal depression. Elytra slightly longer than the pronotum, quadrate or slightly elongate with rounded shoulders and curved lateral margins, finely and densely punctured throughout. Abdomen without raised lateral borders and parallel-sided for the most part, basal tergites rugose across the base, otherwise all segments finely punctured throughout. Legs slender and very long, coloured as above, penultimate segment of all tarsi strongly bilobed. Aedeagus elongate-triangular and evenly narrowed to a pointed apex, the parameres expanded to obliquely-truncate apices.