Melasis buprestoides (Linnaeus, 1761)
This is a local and sometimes common, or even abundant species, with a very wide distribution; from Portugal east to Central and southern Russia and from southern Scandinavia to the Afrotropical region. In the U.K. it is local across Southern England and Wales north to South Yorkshire and Lancashire although records become sparse in the west; it is our most widespread and frequently recorded eucnemid. Adults are active from April to July or sometimes into August, and the typical habitat is beech and hornbeam woodland (also preferring elm on the continent) or parkland with plenty of damaged or fallen timber but beyond this they have been recorded on a wide range of broadleaved wood. The adults are both diurnal as well as nocturnal; at night they may be found crawling on the surface of logs or low down on trunks, and by day moving rapidly on trunks or fallen timber, or flying low over logs, and occasionally they swarm during hot sunshine. The larvae develop in rather hard and dry dead wood, especially in boughs low down on trunks. Adults emerge head first from the wood during early spring.
Among the U.K. fauna this species is quite distinctive and can be confidently identified from reliable pictures. 6-9mm. The entire upper surface is clothed with fine yellowish pubescence which is most dense and obvious on the head and the anterior part of the pronotum. The head is only narrowly visible from above; convex and densely punctured, the large round eyes being obvious in side view. The eccentric placement of the small second antennomere upon the long and curved basal segment is obvious, segments 4-11 serrate in the female and pectinate in the male. The form of the pronotum is distinctive; broadest behind the front angles and narrowed to just behind the sharp and backwardly produced hind angles. The anterior angles are rounded and produced in dorsal view and the surface is strongly and densely punctured, more strongly so in the male. Scutellum obvious. Elytral with striae well impressed and punctured, a little more deeply so in the female, and finely punctured interstices. The lateral margins are strongly sinuate where the broad epipleura become narrow at the level of the metasternum. Legs long and slender, by comparison the male tibiae are broader and the mid- and hind basal tarsal segments are more strongly developed. Tarsi 5,5,5, without bilobed segments.
MELASIS Olivier, 1790
This is a small genus of about 14 species with a worldwide distribution, 4 species occur in the Nearctic region while only M. buprestoides (Linnaeus, 1761) is widespread in Europe. A second species was recently added to the European list; M. fermini Sanchez-Ruiz & de la Rosa, 2003 is known from 2 localities in Spain, it inhabits broadleaf woodland where the larvae have been observed developing in Alnus glutinosa. All the species are of a very distinctive appearance and vary only in fine detail and colour which ranges from pale brown to almost black. All are saproxylic, developing in a wide range of tree species and all are rather local throughout their range, being localized by the habitat requirements, as with all such groups there has been a decline over recent decades, especially in Europe, due to habitat modification.