Rhyncolus ater (Linnaeus, 1758)

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POLYPHAGA Emery, 1886

CURCULIONOIDEA Latreille, 1802

CURCULIONIDAE Latreille, 1802

COSSONINAE Schönherr, 1825

RHYNCOLINI Gistel, 1848

Rhyncolus Germar, 1817

Widespread and generally common in suitable habitats from lowlands to above 2000m throughout Europe from Portugal to Greece in the south and north to the UK and above the Arctic Circle in Fennoscandia, it is present on some of the northern Mediterranean islands but absent from North Africa and the Middle East, further east it extends through Asia Minor and Russia into Siberia. In the UK it is very local and generally scarce; there are a few widely scattered records from Central and Southern England and some older records from the North East but the main stronghold is the Scottish Highlands where it is widespread and, at a very few sites, common. The usual habitat is coniferous and mixed woodland but, as is likely in the UK, adults may appear in apparently inappropriate sites as a result of transportation of timber or transplantation of trees. In the UK the host is usually Scots Pine (Pinus sylvestris L.) but on the continent it is also associated with Swiss Pine (P. cembrae L.), spruce (Picea Mill.), larch (Larix Mill.), firs (Abies Mill.) and thujas (Thuja L.), and less often on a wide range of broadleaf trees including various oaks (Quercus L.), alders (Alnus Mill.), Ash (Fraxinus excelsior L.), hazels (Corylus L.), chestnut (Castanea Mill.), lime (Tilia L.), hornbeam (Carpinus L.), poplar (Populus L.) and willows (Salix). Adults occur throughout the year, they overwinter under bark or among decaying wood and are active from May until October, peaking in abundance during June and July. Larvae develop in decaying damp wood, often where fungi are present, on both living and dead trees, most often conifers but also broadleaf trees, they form meandering galleries as they feed and occur in stumps, logs and exposed roots as well as standing trunks and branches. The species is thought to be univoltine and freshly emerged adults have been found from mid-summer. The nocturnal adults are often active on wood, they fly on warm spring and summer nights and at this time they sometimes appear in numbers in light traps.

Rhyncolus ater 1

Rhyncolus ater 1

3.2-4.2 mm. Elongate and discontinuous in outline, appearing pinched at the waist, glabrous and entirely black to very dark brown with slightly paler appendages, sexual differences are slight but females are broader and have a more rounded pronotum.  Head elongate with small, weakly convex eyes and long, diverging temples, rostrum transverse and at most only slightly widened at the antennal insertions, entire surface finely and moderately densely punctured. Antennae short and robust; scape straight, shorter than the interocular distance and gradually thickened from the basal third, funiculus 7-segmented with all segments short and transverse and the club elongate and only a little wider than the last funicular segment. Pronotum distinctly elongate, broadest behind the middle distinctly constricted before a straight basal margin, laterally narrowed and almost straight to a curved apical margin which is about as broad as the basal margin, surface evenly convex and quite strongly but discretely punctured throughout. Scutellum small but plainly visible. Elytra slightly dilated from rounded shoulders to a continuous apical margin, striae well-impressed and strongly punctured to the apex, and interstices convex and finely punctured. Legs short and robust with unarmed femora that are broadly visible in normal setting. All tibiae with produced into a long curved tooth at the internal apical angle. Tarsi pseudotetramerous with the bilobed third segment clearly wider than the second segment. Claws short, curved and separated at the base.