SALPINGIDAE | uk beetles

SALPINGIDAE Leach, 1815

Narrow Bark Beetles

Includes saproxylic fungus-feeders most easily found around fungus on tree stumps and trunks at night.

POLYPHAGA Emery, 1886

TENEBRIONOIDEA Latreille, 1802

1.5-4.5mm

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Introduction

This is a small cosmopolitan family of about 350 species in 45 genera and 7 subfamilies although the classification is not settled and it may include more than one lineage. By far the greatest diversity is in tropical and subtropical regions and temperate areas tend to have small faunas; 19 species are recorded from Europe of which 14 occur in central Europe and 11 extend to the UK, and the Nearctic fauna includes 20 species. Othniinae LeConte, 1861, often regarded as a distinct family and commonly referred to, though rather unconvincingly, as ‘False Tiger Beetles’ on account of their large convex eyes and metallic colouration which is rendered cryptic by patterns of dense pubescence, includes more than 50 species in 3 genera and is most diverse in tropical regions, especially southeast Asia, Africa and Central America; the large genus Elacatis Pascoe, 1860 includes about 50 species of which 3 extend north into the USA, but none are recorded from Europe. Prostominiinae Grouvelle, 1914 includes 10 genera and about 35 species and is widespread in warmer regions of the world but generally absent from temperate areas. In general little is known of the group; some resemble monotomids and the group has variously been included in Tenebrionidae, Colydiidae and Prostomidae. Agleninae Horn, 1878 includes the single monotypic genus Aglenus Erichson, 1842 which is native to Europe, extending to the UK, but is now almost cosmopolitan. A. brunneus Gyllenhal, 1813 is a small flightless and blind species often found in caves in the wild but is also an occasional pest of stored products and thus has been transported across much of the world. Aegialitinae LeConte, 1862 includes 2 genera; the monotypic Antarcticodomus Brooks, 1951 from several islands off New Zealand, and the northern temperate genus Aegialites Mannerheim, 1853 with about 30 species, most occur in Asia but a few also from the USA and Japan. Species occur in the intertidal zone and are very localized, often to a single island, they often occur in crevices on rocky shores and occasionally swarm in large numbers. Inopeplinae Grouvelle, 1908 is sometimes given family rank, it includes 4 genera of which 3 are monotypic occurring in Japan, Argentina and New Zealand while Inopeplus Smith, 1851, with about 75 species (although this is very likely to be split) occurs mostly in tropical areas worldwide with a few species extending north into Asia, The USA and Japan. Dadocerinae LeConte, 1862 includes 3 genera; the monotypic Tretothorax

Lea, 1911 is Australian while Myrmecoderus Aalbu, Andrews & Pollock, 2005 (3 spp.) and Dacoderus LeConte, 1858 (6 spp.) are New World genera occurring mostly in Central and South America.

Salpinginae Leach, 1815. This is the most diverse subfamily and, with the exception of Aglenus, includes all the UK species. There have been many taxonomic changes over the years but the group now includes about 12 accepted genera; it has variously been divided into 2 tribes, Lissodemini and Salpingini according to whether the pronotal margin is denticulate or not, but no tribal system is in use today and the group is in need of revision. So far as the European fauna is concerned adults are distinguished from those of other subfamilies by the following combination of features: body shiny and often metallic, without distinct pubescence, base of elytra depressed and distinct punctured striae present, and in many groups the head is produced into a rostrum. The group is dominated by several large genera including the Old World Lissodema Curtis, 1833, and the cosmopolitan Sphaeriestes Stephen, 1829 and Salpingus Illiger, 1802, often referred to by the older name Rhinosimus Latreille, 1802, all of which are represented in the UK. Our fauna also includes Vincenzellus ruficollis (Panzer, 1794); this genus includes at least 4 other species and is widespread with 4 from Africa including a Madagascan endemic, one Nearctic species and one from Tasmania. Rabocerus Mulsant, 1859 includes 5 species; one from East Africa and the remainder from Europe with 2 occurring in the UK. Other genera are generally of restricted distribution e.g. Austrosalpingus Blair, 1925, Neosalpingus Blackburn, 1891 and Notosalpingus Blackburn, 189 from Southern Australia, Lanthanus Champion, 1889 from Central America, Platamops Reitter, 1878 from South America and Platysalpingus Blair, 1919 from New Guinea.

Description

Small to medium sized species; 1.5-7.0mm; elongate or elongate-oval and depressed or only weakly convex and with or (mostly) without distinct pubescence. Colour varies widely, there are many drab brown species or drab bicoloured or patterned species but also brightly coloured and metallic groups. The head is short and broad or produced into a broad and flat rostrum, eyes usually large and convex anterior to short and often tapering temples, antennae moderately long, 11-segmented and moniliform or filiform with a variable 3.5 segmented, often loose and elongate, club; in some e.g. Rabocerus, this may be obscure or only weakly developed. Antennal insertions lateral in front of the eyes and exposed or partially concealed under the frons, frontoclypeal suture weak or only indicated laterally (in Aglenus represented by a deep fovea), mandibles short and generally concealed under the labrum, palpi short, narrow and tapering or truncate. Pronotum quadrate to elongate and widest at or in front of the middle, lateral margins bordered and either smooth or denticulate; evenly rounded to strongly constricted behind the middle, surface punctured and often with basal or median depressions. Prosternum usually long anterior to round and either narrowly or broadly separated, open or closed coxal cavities, process variable, from narrowly lanceolate to broad and rounded or truncate. Mesosternum small, with narrowly or widely separated and usually round coxal cavities closed or partly closed by the mesepimera. Metasternum long and convex, anteriorly truncate in contact with the mesosternum, hind coxal cavities widely transverse. Elytra elongate and variously rounded, sometimes e.g. in Rhinosimus, almost parallel-sided, flat or depressed towards the base and convex from the basal third or half, with punctured striae and flat or convex interstices, humeri distinct and epipleura either present only towards the base or distinct to the apex; apices continuously rounded and covering the abdomen. Scutellum usually small but obvious, hind wings usually well-developed. Legs slender and relatively long; anterior and middle coxae convex and often globular with concealed trocantins, femora narrow or only weakly dilated about the middle and lacking teeth or other sculpture, tibiae slender, straight and only weakly broadened towards the apex, apical spurs small and inconspicuous. Tarsi 5-5-4 in both sexes; segments not or only weakly lobed, the terminal segment generally long and slender. Claws variable but usually small; smooth and lacking a basal tooth.

Larvae are elongate, sub-parallel, moderately to strongly flattened and weakly sclerotized except for the head and abdominal apex. Most are creamy or yellowish in colour and smooth with sparse long setae to the dorsal surface. Head prognathous with strongly sclerotized and symmetrical mandibles, the legs are well-developed and the urogomphi robust and branched. They generally occur under bark or among decaying wood of a range of both broadleaved and coniferous trees and many are listed as predators of bark beetles or other insects.

Ecology

Species of Salpinginae are generally associated with bark and decaying wood on dead and dying trees of all kinds although some develop in small branches or twigs, and all are thought to be predatory on other insects etc. both as adults and larvae. Areas of wood infested with bracket-fungi are often very productive and in general searching at night, when the beetles are active on the surface, is the best way to find them although they will usually occur among many other species. In the UK several species are common and widespread and should soon be found when working bark and dead wood generally, these include Salpingus planirostris (Fabricius, 1787), S. ruficollis (Linnaeus, 1760), Vincenzellus ruficollis (Panzer, 1794) and, to a lesser degree, Sphaeriestes castaneus (Panzer, 1796), on dead and dying conifer branches, and S. reyi (Abeille, 1874) among burnt twigs. Sphaeriestes stockmanni (Biström, 1977) is a very local species occurring in Scotland and Ireland. Both our species of Rabocerus are widespread though very local and rare and, in common with many saproxylic species, seem to have declined recently. Lissodema cursor (Gyllenhal, 1813) is widespread and generally rare, though maybe under-recorded, in southeastern England; it develops in dead and dying branches high up in mature ash trees. L. denticollis (Gyllenhal, 1813) is more widespread and common in the south and occurs in a wide range of trees including pine. Aglenus brunneus (Gyllenhal, 1813) is a worldwide pest of stored products with scattered records from southern England and Wales.