Trichophya pilicornis (Gyllenhal, 1810)
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POLYPHAGA Emery, 1886
STAPHYLINOIDEA Latreille, 1802
TRICHOPHYINAE Thomson, C.G., 1858
TRICHOPHYA Mannerheim, 1830
Trichophya pilicornis is the most widespread member of the subfamily; it occurs across North Africa, including the Azores, Madeira and the Canary Islands, throughout Europe to far beyond the Arctic Circle in Scandinavia and east through Asia Minor, the Caucasus and Russia to Siberia and Eastern India. Specimens from Madeira have long been referred to as a distinct species, T. huttoni Wollaston, 1854 but this is now considered as conspecific with pilicornis. It was introduced to North America during the 19c by human activity; first recorded in 1895 from New York and known from Canada since 1905 it is now widespread, in Canada it is common in boreal forests though less so further south. In the UK it is a very local and generally scarce species across southeast England, the midlands and Wales, it has recently been recorded from Ireland and there are a few older records from Scotland. Adults are nocturnal and difficult to find by day; they remain among deep leaf-litter, under moss or in decaying wood or fungi on woodland margins. They fly in the evening and have been recorded entering windows in numbers (Fowler). On the continent they occur in caves and among straw stored in barns and in Canada they are found among litter in conifer forests.
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​Among our UK fauna this species is very distinctive as outlined above. 3.5mm. Shiny black with the elytra rather dull and often paler in colour, legs dark to pale brown with the tarsi pale. Head finely and rather densely punctured, black with the mouthparts dark red, antennae typical of the genus. Pronotum transverse with the anterior and posterior margins about equal in width and the lateral margins rounded, surface finely punctured. Elytra transverse and much longer then the pronotum, very finely and densely punctured. Abdomen broad and only weakly narrowed in the basal two-thirds, black with the apex of each segment pale, finely and densely punctured and pubescent and with longer setae on the posterior angles. Male protarsal segments slightly dilated.
TRICHOPHYINAE Thomson, C.G., 1858
This is a small Holarctic subfamily of about 15 species included in the single genus Trichophya Mannerheim, 1830. The phylogenetic position of the group has long been problematic and it has variously been included within the Tachyporinae or Habrocerinae or considered closely related to the Aleocharinae or Phloeocharinae, its present status as a distinct subfamily most closely related to the Habrocerinae is widely accepted. Most occur in the Palaearctic region and one of these, T. pilicornis (Gyllenhal, 1810), is adventive and now widespread in the United States, having been first recorded there in 1895. The European fauna may include 2 species; the widespread T. pilicornis and the much more local T. foina Gistel, 1857 (Nomen Dubium) which occurs in Germany. The majority are of rather localized distribution; 4 are restricted to India, 3 to Japan and one each to China and Malaysia; only 2 are widespread, T. rudis Cameron, 1926 occurs in India, Nepal and China while T. pilicornis occurs across Europe. Three species are native to North and Central America, and another has recently been discovered in Mexico and Guatemala (Ashe, J.S. & Newton, A.F., Systematic Entomology 18(4):267-286).
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All are small, 3-4 mm, and resemble Tachyporinae (fusiform) in general but the antennal structure is unusual; the two basal segments are large while the remainder are very thin with a ring of stiff setae around the apex of each, similar to those seen in Habrocerinae. The body is dark brown to black when mature, the entire dorsal surface shiny and very finely punctured and pubescent and the appendages extensively pale. Head very distinctive; strongly and broadly produced in front of relatively large and convex eyes and with long and strongly converging temples, surface evenly convex and finely and quite densely punctured. Antennae inserted laterally in a cavity some distance anterior to the eyes, rather like members of Tachyporinae. Labrum entire and rounded anteriorly, mandibles triangular with a large basal lobe and several small teeth before the apex, labial palps small and 3-segmented, maxillary palps long and robust; unusual in having an extra tiny apical segment so 5-segmented. Pronotum transverse, strongly rounded laterally and evenly convex but depressed inside obtuse posterior angles. Posterior margin sinuate laterally and weakly produced across the middle. Scutellum triangular and relatively large; punctured and pubescent as the pronotum. Elytra transverse and weakly dilated towards the apex, sutural and epipleural margins not bordered and posterior margin separately rounded. Abdomen with strongly raised lateral margins, apical margins of all segments with long stiff setae, clearly visible along the margins in dorsal view, basal tergites with a fine transverse impression. Legs long and slender, tarsi 5-segmented; basal segments of pro- and mesotarsi dilated in the male.
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They differ from Habrocerus in having transverse meta-coxae; our single U.K. species is distinct in the form of the pronotum; here it is broadest across the middle whereas in Habrocerus it is broadest across the base.
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​Species are associated with fungi, moss, leaf litter and wood debris in wooded situations and parkland and decaying vegetation in a range of habitats including agricultural situations. Adults may be sampled by sieving leaf-litter and debris or by pitfall trapping in wooded situations. Some foreign species are associated with mammal nests. So far as is known all species are mycophagous and facultative predators.