Dromius quadrimaculatus (Linnaeus, 1758)
With the exception of most of the Iberian Peninsula this generally common Western Palaearctic species occurs from lowlands to the tree-line throughout central and southern Europe north to the southern provinces of Sweden and the UK, to the east extending to the Caucasus and Central Russia. Here it is common throughout England and Wales, including all the islands, and sporadic and much less common north to the Scottish Highlands. It is generally associated with deciduous and mixed woodland and parkland; only in some northern European areas does it occur in coniferous woodland, the adults roam during the evening and through the night hunting for small insects, mites and springtails etc. on the bark of healthy trees as well as dead and dying wood and fence-posts etc, but during hot summer days they occasionally take flight and may be swept above grass or around foliage in wooded areas. During the day they remain under bark, within tight bark crevices or among tussocks or litter at the base of trunks. Adults are present year-round, they overwinter under bark etc. and are active very early in the year; when searching trees they will be among the first species recorded, often during mild spells in January and often alongside Paradromius linearis or Calodromius spilotus, they are generally common by March or April and remain active until at least November and often into December. Mating occurs from March or April and mating pairs may be found into June, larvae have been recorded from June to August; they are predatory and develop mostly under bark but may hunt on the surface by night. New generation adults appear from July and will go on to overwinter. Recording is simply a matter of searching tree trunks at night; the adults are conspicuous by torchlight and easily seen, during the warmer months they tend to occupy higher branches but they descend during cooler times and are easily recorded during spring and autumn they tend to occur low-down and are easily spotted. Adults may occur in flight-interception traps and are also occasionally attracted to light.
5-6mm. A very distinctive species; the size and colouration should be diagnostic. Head black; usually with the clypeus and labrum pale, pronotum reddish-brown, elytra black with extensive pale markings, appendages pale or the antennae darkened towards the apex. Head extensively rugose, with large convex eyes and long tapering temples, inner margin of eyes with two setiferous punctures, antennae finely and densely pubescent from the fourth segment. Pronotum transverse and distinctly narrower than the elytra, widest behind rounded anterior angles and narrowed to obtuse posterior angles, lateral margins raised, basal margin straight. Scutellum dull due to microsculpture. Elytra dilated towards the apex, with smoothly rounded shoulders and truncate apical margin, striae weakly impressed and finely punctured, interstices flat, and the eighth with larger punctures. Elytral surface shiny but with distinct microsculpture (X20), each with a large pale macula near the base and the apical area extensively pale. Tarsi without bilobed segments, claws denticulate.
Elytra dark at apex.