Anomognathus cuspidatus (Erichson, 1839)

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POLYPHAGA Emery, 1886

STAPHYLINOIDEA Latreille, 1802

STAPHYLINIDAE Latreille, 1802

ALEOCHARINAE Fleming, 1821

HOMALOTINI Heer, 1839

Anomognathus Solier, 1849

This widespread and locally common species occurs from lowland to middle-mountain altitudes throughout Europe from Spain to Greece and Turkey in the south and to the UK and far above the Arctic Circle in the north, it has also been recorded from China, it is widespread in north west Africa and has been widely reported from North America but it is likely this is based on a different species. Here it is generally common throughout England and Wales north to Yorkshire though absent from the West Country, very local and sporadic further north to the Scottish border and very local and rare in Northern Ireland. Typical habitats in the UK are broad-leaved woodland and wooded parkland with trees in various stages of decay, they also occur on individual trees in wasteland and gardens, on the continent they are also commonly associated with various conifers including Pine and Norway spruce in conifer plantations. Adults are mostly recorded from September to June although they probably occur over a longer season, they are associated with bark in the early stages of decay and will often be found under close-fitting bark that is still damp, more generally they occur near fungal fruiting bodies although no specific associations are known and it is likely they frequent such habitats simple to predate the early stages of fungivorous flies and beetles. They have been recorded from a wide range of trees including oak, beech, sycamore, horse chestnut, poplar, willow and birch, and are often associated with bark beetle and goat moth (Cossus Cossus (L, 1758)) galleries. Little is known of the biology but both adults and larvae are thought to be predaceous, adults usually occur in numbers, especially through the winter, and while the flight capacity is not understood, they have been recorded from flight-interception traps, they are sometimes active on the surface at night and have been recorded in numbers at sap in the spring. Adults may be sampled by lifting recently dead bark, especially in the autumn and winter, and especially around wounds at the boundary of dead and healthy bark, but they rarely remain once the bark starts to become loose and accumulate debris. Because they are tiny and slender they are easily overlooked, there are also several other tiny staphs in this habitat and so they will need to be looked for very carefully.

Anomognathus cuspidatus 1

Anomognathus cuspidatus 1

© Lech Borowiec

Anomognathus cuspidatus 2

Anomognathus cuspidatus 2

© U.Schmidt

1.5-2.2 mm. Very depressed and rather parallel-sided, entirely dark brown with the legs and antennal bases yellow, rather nondescript but easily identified by the form of the sixth abdominal tergite which is produced into three spines; a long and straight spine at the centre and a shorter and slightly curved spine at each side. Dorsal surface finely sculptured and punctured and with fine pale pubescence. Head slightly elongate with small, weakly-convex eyes and long, curved temples, surface flat and without sculpture, penultimate maxillary palpomere enlarged, terminal segment diminutive. Antennae inserted laterally in front of the eyes, segments 1-3 elongate, 4-10 progressively more transverse and the terminal segment elongate and rounded apically. Pronotum transverse, at most only slightly wider than the head, lateral margins straight, all angles widely rounded. Elytra quadrate and much wider than the pronotum, with rounded shoulders and near-parallel lateral margins, basal margin almost straight. Abdomen weakly dilated about the middle, strongly bordered, fifth tergite bisinuate. Femora broad and flat, especially the hind pair, tibiae narrow; the middle and hind tibiae with a small but distinct apical spur, and the front tibiae with a single erect seta in the basal half. Tarsi 4-4-5.

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