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Strigocis bicornis (Mellié, 1848)







POLYPHAGA Emery, 1886

TENEBRIONOIDEA Latreille, 1802

CIIDAE Leach, 1819

CIINAE Leach, 1819

CIINI Leach, 1819

Strigocis Dury, 1917

This Western Palaearctic species occurs mostly in central and southern Europe although there are widely scattered records from Spain to the Middle East. In Europe it occurs very locally from France to Germany and Hungary, it is absent from the Baltic countries but present in the UK which represents the northern-most limit of the distribution. In the UK there are widely scattered records in Southern and Central England and South Wales, but it is generally scarce and infrequently recorded. The species is usually associated with old established deciduous woodland where it occurs among fungi on beech (Fagus L.) or ash (Fraxinus L.), but other hosts have been recorded. Host fungi include various species of Trametes, commonly T. versicolor (L.) Lloyd (1920) and T. gibbosa (Pers.) Fr. (1936) but also other species. Adults are present year-round; they overwinter in host fungi or among adjacent bark or decaying wood, and are active from March until September, peaking in abundance during May and June, and again in September. Little is known of the biology but both adults and larvae are mycophagous and larvae develop within the hosts. Trametes tends to grow low down on decaying trunks and stumps, and these are the best specimens to sample for adults, especially where the fungus has been established for a few seasons and developed extensive growth. Despite being very local and scarce, the species is usually common where it occurs. Adults sometimes occur on the surface of wood or host material at night, but taking samples for extraction or to keep in order to breed out the fauna are the best ways to find the species, and large numbers of adults may occur in a single sample. Adults are fully-winged and capable of flight, but they generally do not appear in flight-interception traps or at light.

Strigocis bicornis

Strigocis bicornis

© Udo Schmidt

1.2-1.5 mm. Elongate, discontinuous in outline and strongly convex, body dark brown to black with very fine pale scales which can appear as dust in some lights, appendages pale brown or with darker antennal clubs. Head deflexed and mostly hidden from above, vertex and frons rather flat between round and protruding eyes, frontoclypeal suture distinct and cheeks strongly converging. Antennae 10-segmented with a loose 3-segmented club, segments 1-4 elongate, 5-7 transverse, and 8-11 globose. Pronotum quadrate or slightly transverse, broadest behind the middle and narrowed to a rounded apical margin and obtuse posterior angles, basal margin finely bordered laterally, surface finely and evenly punctured and very finely microsculptured throughout. Elytra evenly curved from obtuse shoulders to a continuous apical margin, surface finely and randomly punctured throughout. Front tibiae broadly expanded and with a series of fine spines across the apex. Middle and hind tibiae less strongly expanded, and without obvious apical spurs. Tarsi 4-segmented; basal segments short and weakly lobed, terminal segment long and expanded from the base. Claws smooth, weakly toothed at the base. Anterior pronotal and clypeal margins with a pair of teeth in males, simple in females.

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