Dissoleucas niveirostris (Fabricius, 1798)
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POLYPHAGA Emery, 1886
CURCULIONOIDEA Latreille, 1802
ANTHRIBINAE Billberg, 1820
ZYGAENODINI Lacordaire, 1865
Dissoleucas Jordan, 1925
A Palaearctic-wide species extending to the far east of Russia, China and Japan and also recorded from Borneo, in Europe it is widespread from the Pyrenees to Ukraine and extends north to the UK, Denmark and the Baltic countries where it reaches into southern provinces of Norway and Sweden, also recorded from many of the Mediterranean islands but seemingly absent from North Africa. It tends to be locally common in central areas from France to Slovenia and Poland and in Fennoscandia but is otherwise very local. In the UK it is very local and known from only a few widely-scattered records in southern and central England. The usual habitat is broadleaf woodland and wooded parkland with plenty of dead and decaying trees but they also occur in older hedgerows and among brushwood, and in Northern Europe they are frequently recorded from Spruce-dominated forests with dense shrub and herbaceous undergrowth. Adults are present year-round; they overwinter under bark or among decaying wood and are active from May until August or September, peaking in abundance during May and June. They are mostly nocturnal but will often sit exposed on small branches or twigs in warm weather, at night they are active on the surface of dead wood although they usually occur as single specimens or pairs and may be very difficult to find. Larvae feed in dead or decaying branches and are thought to be either mycophagous or xylophagous (or both?), they have been recorded from Oak (Quercus L.), Hornbeam (Carpinus L.) and Apple (Malus Mill.) but are likely to use a range of trees and shrubs. Adults have been recorded from a wide range of broadleaf trees and shrubs and beating hedgerows or brushwood is said to be a good way to find them.
2.0-4.0 mm. Elongate and discontinuous in outline, dorsal surface patterned with black, white and pale brown scales, antennae red with darker clubs, legs dark to pale brown with bands of white scales. Head flat or slightly concave between large and prominent eyes that occupy most of the lateral margins, rostrum short and transverse, expanded in front of the eyes and unevenly curved anteriorly. In most specimens the frons and rostrum are covered, or partly covered, in long white scales. Antennae inserted laterally under the rostrum, 11-segmented with a loose 3-segmented club, segments 2-8 narrow and elongate. Pronotum transverse, broadest across obtuse angles in front of obtuse posterior angles and unevenly narrowed to obtuse anterior angles, apical margin uneven, basal margin almost straight, surface uneven and densely punctured, before the base with a sinuate raised bead between the lateral angles. The pronotal colour varies a little but usually includes a white median strip and two or three transverse bands of longitudinal brown scales. Scutellum transverse and covered with dense white scales. Elytra almost parallel-sided from rounded shoulders to a continuous apical margin, surface finely and densely punctured and with punctured striae that are usually obscured by scales. Elytral colour usually includes grey scales to the even-numbered interstices and black, brown and white scales forming a mottled pattern on the odd-numbered interstices, the declivity is usually covered in white scales and, in side view, the patches of dark scales on the third interstice are raised. Legs long and slender; femora unarmed, tibiae smooth and without obvious apical spurs. Tarsi pseudotetramerous with the second segment partly enclosing the third, and the fourth diminutive and mostly hidden within the bilobed third segment. Males can be distinguished by the curved tooth at the apex of the middle and hind tibiae and the longer antennae when compared with females.