Platystomos albinus (Linnaeus, 1758)

Bird-dropping Weevil

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POLYPHAGA Emery, 1886

CURCULIONOIDEA Latreille, 1802

ANTHRIBIDAE Billberg, 1820

ANTHRIBINAE Billberg, 1820

PLATYSTOMINI Pierce, 1916

PLATYSTOMOS Schneider, D.H., 1791

This very distinctive weevil occurs locally across Wales and southern and central England although it appears to be generally absent from the West Country and is more generally rare, it is typically an insect of established woodland but may also be found on logs or stumps in parkland or moorland. Adults have a long season, from February until October, peaking in early summer, they are nocturnal but often spend the day exposed on logs or trunks where they are very cryptic and might be mistaken for bird droppings, and when found the immediate area should be carefully searched as they often occur in numbers. They generally occur on wood infected with fungi, commonly Daldinia concentrica on ash but they have been recorded from a wide range of trees including oak, willow, birch (upon which they are particularly well camouflaged), beech and alder. The larvae develop within decaying branches, trunks or fallen timber of a similarly wide range of broadleaf tree, and while they are not associated with fruiting bodies, they are thought to feed upon mycelia in the wood. Abroad the species has a very wide range; from the Mediterranean to high above the Arctic Circle; from Spain east through the Middle East and Asia Minor to (at least) Lake Baikal, occurring from lowland to mountain altitudes, and throughout most of this range it is locally common although in some areas e.g. France, it is very local and rare.

This large and distinctively coloured weevil might only be confused with the similarly large Platyrhinus but is distinguished by the patches of white scales on the elytral disc and the lack of a pronotal keel. 7-10mm; the females generally much larger than males, entire beetle with dense recumbent grey, brown or black pubescence except that on the head, elytral disc and apex, and bands on the tibiae white. Head, including rostrum, elongate with convex and prominent eyes, short temples and a longitudinal furrow which is usually visible through the pale scales. Antennae placed laterally before an apical rostral dilation, the scrobes round and deep behind the insertions but hidden from above. Antennae strongly sexually dimorphic; much longer and with a longer and narrower club in the male, black with the apex of segments three to seven variously pale, segment eight often entirely pale. Pronotum quadrate (female) or slightly transverse (male), broadest and weakly angled near or behind the middle, surface with only fine punctures and three patches of erect dark pubescence across the disc. Elytra with prominent shoulders and parallel-sided to a continuously rounded apex, dark scales orientated at various angles and so appearing cryptic, generally those on alternate interstices alternately dark and paler grey from the base to the apical pale scales, third interstice with four patches of erect black scales; one towards the base and three between the middle and the declivity, apex with extensive pale scales, usually from the declivity. Legs long and robust, femora with patches of brown and black scales, tibiae with bands of brown, black and white scales, tarsi dark with pale scales to the apex of segments, terminal segment often entirely pale, claws with a strong and sharp internal tooth.

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