Melanotus villosus (Geoffroy in Fourcroy, 1785)

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POLYPHAGA Emery, 1886

ELATEROIDEA Leach, 1815

ELATERIDAE Leach, 1815

MELANOTINAE Candèze, 1859

Melanotus Eschcholtz, 1829

The distribution of this species must remain tentative because it is very similar to another member of the genus, M. castanipes (Paykull, 1800), there has also been confusion regarding the names as ‘castanipes’ was formerly confused with ‘villosus’, and so unless records have been reliably and relatively recently verified they may be subject to doubt. Despite this the present species is known to be widespread across the Western Palaearctic region; it is generally common throughout Europe from the Pyrenees north to the UK and reaching the Arctic Circle in Fennoscandia, it extends east through Asia Minor and Russia into Siberia and is widespread in western North Africa. In the UK is it common throughout England and Wales, including the islands but probably not on Man, and very local and scarce in Scotland and Northern Ireland. Typical habitats are lowland broadleaf woodland and wooded parkland although on the continent it occurs at higher altitudes in mountain valleys, but it may also occur more generally wherever there is a good supply of dead and decaying wood e.g. it is often common on waste ground and disturbed areas including domestic gardens. Hosts include a wide range of broadleaf trees, much more rarely conifers, and suitability depends more on the condition of the wood than the species. Adults are present year-round, they overwinter among debris under loose bark or within soft wood and are active from April or May until October or November, peaking in abundance from May until July. They are mostly nocturnal; during the day they shelter under bark or in crevices or hollows and become active at dusk when they may be observed on trunks or fallen timber, they usually occur as single specimens or pairs and they sometimes fly on dark nights, occasionally coming to artificial lights and moth traps. Mating occurs in late spring and early summer and the majority of adults die off by August, eggs are laid in decaying trunks or fallen timber, often where it has been previously infested by fungi and usually hosting plenty of wood boring insects and their early stages. The larvae are predatory, first instars live under bark or in scolytid or Cossus galleries but later stages are able to burrow through soft wood in search of prey, thus they may enter roots or even burrow into surrounding soil, they develop over three or four years but this may be extended by one or two years where prey are scarce or when conditions become unfavourable. Pupation occurs in a cell in soft wood or under bark during July and August, this stage lasts about five weeks and adults are fully formed by the autumn but they tend to remain in situ until the following spring. Adults may be found on trunks etc at night, they are large and tend to remain still when illuminated and so are easy to find, they may also be found among soft wood, usually where it is damp and there is accumulated debris, and often in wetland marginal situations, this is a good method of finding them in the colder months although it tends destroy, or at least disturb, the habitat of other overwintering insects e.g. locally we have often found them under loose bark in the vicinity of overwintering hornets (Vespa crabro L.) or queen wasps (Vespula Th.).

Melanotus villosus 1

Melanotus villosus 1

Melanotus villosus 2

Melanotus villosus 2

Melanotus villosus 3

Melanotus villosus 3

13.0-20.0 mm. Distinguished among out UK species (along with M. castanipes) by its large size and dark colouration although teneral specimens may be dark reddish-brown, entire body black with fine pale pubescence, legs and antennae dark brown, sometimes almost black. Head from above widely transverse with convex eyes, evenly convex and moderately-strongly and discretely punctured, clypeus more sparsely so with many punctures separated by at least a puncture width and in places more widely so. Antennae long and slender; the basal segment short and curved, 2 and 3 quadrate to slightly elongate and together shorter than 4, and 4-10 slightly serrate. Pronotum slightly transverse, broadest behind the middle and curved to a narrow apical margin, laterally slightly narrowed to distinctly sinuate before produced and excavate posterior angles, from above the lateral margin is visible throughout, surface evenly convex (viewed at a low angle from in front or behind) and without a fine median ridge, moderately strongly but not densely punctured and posterior angles finely keeled externally. Elytra very elongate, broadest behind rounded shoulders and gradually narrowed to a continuous apical margin (at higher magnification the apices diverge slightly at the suture), each with punctured striae which may become confused in places and usually fade in the apical quarter, interstices flat or weakly convex, and with one or two indistinct rows of fine punctures. Legs long and slender with tibiae only weakly broadened from the base and with very fine apical spurs, tarsi 5-segmented with all segments elongate and obvious. Claws finely serrate and without a basal lobe.