Enicmus transversus (Olivier, 1790)

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POLYPHAGA Emery, 1886

CUCUJOIDEA Latreille, 1802

LATRIDIIDAE Erichson, 1842

LATRIDIINAE Erichson, 1842

Enicmus Thomson, C.G., 1859

Widespread and generally common across the Palaearctic region and extending into tropical Africa and the Oriental region, this species occurs throughout Europe and North Africa and is present on most of the Mediterranean and Atlantic islands, to the north it reaches the UK and extends above the Arctic Circle in Fennoscandia. In the UK it is common across southern and central England and Wales, less so in Northern England, and very sporadic and rare in Scotland and Northern Ireland. Adults are present year-round, peaking in spring and summer but often common and remaining active through the winter. The species occurs in a wide range of habitats including deciduous and coniferous woodland, wooded parkland, damp grassland, coastal dunes and beaches, it often occurs in disturbed habitats such as wasteland and domestic gardens and is often synanthropic, occurring among decaying organic matter in stables and outhouses etc. Adults have been recorded from debris under bark on decaying deciduous and coniferous trees, usually in the vicinity of fungal infections, among decaying vegetation in almost any situation, and, on the continent, from ant (Formica L.) and bird nests. Typical of the family, both adults and larvae feed on fungal spores and mycelia in damp situations and breeding probably continues through the milder months. Adults are crepuscular and nocturnal, they may be found on the surface of trunks and fallen timber, especially where fungi are present, they are fully-winged and occur in flight-interception traps but not, it seems, at light or sap. Sieving decaying vegetation or taking samples for extraction are the best ways to find adults but they usually occur in small numbers and sometimes along with similar species and so will need to be looked for very carefully.

Enicmus transversus 1

Enicmus transversus 1

© U.Schmidt

Enicmus transversus 2

Enicmus transversus 2

© Lech Borowiec

1.7-2.2 mm. Elongate and discontinuous in outline, entirely pale to dark brown, often with the head darker and the pronotal margins paler, appendages pale brown. Head with large, convex eyes and protruding, obtusely-angled temples, cheeks about as long as the eyes and converging anteriorly, surface rugose and densely punctured, without keels but sometimes depressed medially towards the base. Antennae inserted laterally in front of the eyes, long and slender with segments 9-11 distinctly broader than 3-8. Pronotum slightly transverse, widest in front of the middle and curved to produced anterior angles and toothed posterior angles, apical and basal margins weakly curved and lateral margins very finely dentate. Pronotal disc uneven and moderately strongly punctured, explanate margins mostly unpunctured, with well-impressed basal fovea and sometimes impressed medially but without longitudinal keels. Prosternum raised between the coxae. Elytra elongate-oval and smoothly curved from rounded and slightly produced shoulders to a continuous apical margin, each with regular punctured striae, the innermost fading towards the apex, and flat, unpunctured interstices which are very slightly narrower than the striae. Femora unarmed and all of similar size, tibiae only weakly broadened from the base, without external spines or apical spurs. Tarsi 3-segmented and simple.