LEBIINI Bonelli, 1810

Lebiina Bonelli, 1810 includes more than 800 species in 25 genera and is cosmopolitan in distribution, the large genus Lebia Latreille, 1820 accounts for most of this diversity; it includes more than 700 species in 17 subgenera (although some of these are sometimes considered to be distinct genera) and most occur in tropical and subtropical regions; 18 species occur in Europe and about 50 in North America but only 5 have been recorded from the UK and of these 2 are considered to be extinct. The European fauna otherwise includes a widespread Asian species, Rhopalostyla virgata (Motschulsky, 1844) that extends into South European Russia. Lebia are medium-sized and broadly-oval carabids that are often brightly-coloured and metallic, they are diurnal and nocturnal and may be found under debris or among litter during the day buy many are also active on the ground or among foliage in warm weather. Many occur on light sandy or calcareous soils and most are predatory in all stages although some parasitize chrysomelid larvae, they are typically active over a long season and in temperate regions are univoltine. The very widespread Palaearctic species L. chlorocephala (J. J. Hoffmann, 1803) occurs throughout the UK north to central Scotland although beyond the Welsh coast and the south of England it is very local and generally rare. L. cyanocephala (Linnaeus, 1758) has a more restricted western Palaearctic distribution but is present throughout much of Europe and was formerly widespread though very local and scarce across the south of England but since 1960 has been known from a single heathland site in Surrey. The only other species likely to be found in the UK is L. cruxmajor (Linnaeus, 1758), this is among the most widespread members of the genus, occurring continuously from Western Europe to the far east of Russia, China and Japan and across North Africa and The Middle East; it may also be locally common in Southern and Central Europe but here it is known from only a few sites in the south of England and Ireland. Two more species have been recorded from the UK, L. marginata (Geoffroy in Fourcroy, 1785) and L. scapularis (Geoffroy in Fourcroy, 1785), both have a very restricted European distribution and are rare in central and northern regions and neither has been seen in the UK since the 19th century.

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Cymindidina Laporte, 1834 includes 10 genera and is distributed throughout the world with the exception of Australia. The greatest diversity is in the northern hemisphere and the group is dominated by the large genus Cymindis Latreille, 1805, this includes about 200 species in 14 subgenera-although some of these will occasionally be found in the literature as full genera-and is Holarctic, extending south into the Oriental and Neotropical regions (Costa Rica). The European fauna is very diverse with about 65 species of Cymindis and a single species each of Pseudomasoreus Desbrochers des Loges, 1904 and Trichis Klug, 1832; by contrast the Nearctic fauna consists of 27 species of Cymindis. Most of the European species occur in southern and western regions and many extend into North Africa and/or Asia and only 3 have been recorded from the UK; the very local and rare C. macularis Mannerheim in Fischer von Waldheim, 1824 is known only from Suffolk while C. axillaris (Fabricius, 1794) and C. vaporariorum (Linnaeus, 1758) are more widespread, the former being more restricted and southern and both generally rare. Species of Cymindis inhabit a wide range of terrestrial habitats and many are stenotopic, in the UK C. macularis and C. axillaris occur on dry heaths and grassland while C. vaporariorum inhabits wet heathland and bogs. Our species are medium sized, 7.0-10.5mm, and may be distinguished by the entirely pale antennae, lack of bilobed tarsal segments, punctured elytral interstices and pectinate claws.

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Demetriadina Bates, 1886 is represented in Europe by 4 species of Demetrias Bonelli, 1810, 3 of these are widespread and extend to the UK while D. muchei Jadlicka, 1967 is restricted to a small area of south west Russia. D. monostigma Leach in Samouelle, 1819 and D. imperialis (Germar, 1823) are associated with wetlands, the former very local and often coastal in England and Wales and the latter a very local species of reed beds in south and east England. D. atricapillus (Linnaeus, 1758) is associated with dry grassland and scrub habitats; it remains generally common across England, Wales and Ireland but has declined over recent decades. All species are small, 4.5-5.0mm, and pale brown with various patterns of dark colour and as such may be distinguished among our fauna by the strongly bilobed fourth tarsal segments.

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Pericalina Hope, 1838 includes no native European species but the tropical African Somotrichus unifasciatus (Dejean, 1831) has been transported worldwide in foodstuffs and is occasionally temporarily established across Europe including the UK. It may be distinguished among our fauna by its size, 3.0-4.5mm, colour and the form of the pronotum; transversely cordate with the basal margin produced medially-resembling a Bembidion but with fully-developed maxillary palps and an entirely pubescent dorsal surface. Adults live among stored products where they prey on other pest species; they have been recorded through the year but so far are restricted to artificial conditions.

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The remainder of our species are classified within Dromiusina Bonelli, 1810. From a purely practical viewpoint our species may be divided into two groups according to antennal colour but in any case, apart from some species of Philhorizus Hope, 1838 which may need to be dissected, with a little experience identification is straightforward.

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Description

The following species have entirely, or at least substantially, pale antennae; at most the apices may be darkened but not sharply contrasting with the basal segments. Paradromius Fowler, 1887 is a mostly western Palaearctic genus of 30 species, at least 16 occur in Europe and while many are restricted to certain areas, 2 very widespread and extend north to the UK; P. linearis (Olivier, 1795) occurs throughout the UK and is generally common while P. longiceps (Dejean, 1826) is a very local and rare insect known from a few wetland sites in eastern England. Both may be distinguished by their elongate and flattened form, pale colour and simple tarsi. Dromius Bonelli, 1810 is a large and widely distributed Old World genus that is also represented in North America by a single native species and an established introduction from Europe; it includes about 105 species and is very diverse in the Western Palaearctic region with 14 known from Europe. Three widespread and common Eurasian species  occur in the UK, D. agilis (Fabricius, 1787) and D. meridionalis Dejean, 1825 are locally common while D. quadrimaculatus (Linnaeus, 1758) tends to be common or even abundant in suitable habitats everywhere, all occur on deciduous trees in woodland and wooded parkland and are nocturnal. D. angustus Brullé, 1834 has a more restricted and mostly Western European distribution; in the UK it is a widespread but very local and predominantly eastern species of coniferous woodland. Among our fauna they may be distinguished by the size, 5.5-7.0mm, broad habitus with small and transverse pronotum, simple tarsi and smooth claws. Of the 3 European species of Calodromius Reitter, 1905, only C. spilotus (Illiger, 1798) is widespread and extends to the UK, here it occurs in dry grassland throughout most of the UK and is generally common in the south. Adults may be recognized by the small size, 3.8-4.5mm, quadrate pronotum with protruding posterior angles and the broad elytra which have an entire basal border and 2 pale markings on each. The Palaearctic and African genus Philorhizus Hope, 1838 includes about 50 species; 30 occur in Europe and one of these, P. melanocephalus (Dejean, 1825) has become established in North America. Five widespread species occur in the UK; P. melanocephalus is a common grassland species in the south while the others are very local and scarce; P. notatus (Stephens, 1827) and P. vectensis (Rye, 1873) are coastal species of dry grassland and dunes, mostly in the south, P. sigma (Rossi, 1790) occurs in wetlands in eastern England, and P. quadrisignatus (Dejean, 1825) is a widespread but mostly eastern species of deciduous woodland and wooded parkland. All are broad and small, 2.8-4.4mm, and have a transverse pronotum with distinct posterior angles that do not protrude, the elytra are pale with various dark markings which might sometimes suggest Calodromius but the form of the pronotum is distinctive.

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The following species distinguished by their small size and dark colour; in all the antennae are either entirely dark or, at most, paler towards the base. Lionychus quadrillum (Duftschmid, 1812) is a very local insect of coastal shingle and dunes in the south with scattered and sometimes inland records further north to Yorkshire. Adults are distinctive due to the entirely black body with four (sometimes only two, one beneath each shoulder) pale elytral maculae and the form of the pronotum; very strongly constricted and sinuate before tiny, tooth-like posterior angles. Microlestes Schmidt-Göbel, 1846 is a large Holarctic genus which extends south into Mexico and Africa, it includes about 130 species of which 29 occur in Europe and 2; M. maurus (Sturm, 1827) and M. minutulus (Goeze, 1777)  extend north into the UK , both are locally common dry and sparsely vegetated habitats in the south east of England. Syntomus Hope, 1838 is Holarctic although only a single species occurs in North America. It includes more than 50 species and is widespread in the Old World, the greatest diversity is in Asia and 19 species occur in Europe, most of these in the south or having a restricted distribution, but 3 widespread species extend into the UK. All our species are locally common in the south and east of England but very local and scarce further north; they occur among decaying vegetation etc. in open situations such as grassland, arable land, heaths and moors, and adults may be found year-round.  Species of these 2 genera are small, 2.5-3.8mm, and black to dark brown in colour although S. foveatus (Geoffroy in Fourcroy, 1785) has a metallic bronze reflection and S. obscuroguttatus (Duftschmid, 1812) may have indistinct pale humeral maculae, but they are otherwise superficially similar, there are differences in the form of the elytral apex but the easiest way to distinguish them is by the third antennomere; pubescent in Microlestes and mostly glabrous in Syntomus.

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Two other UK species are variously classified within tribes of the Lebiinae or within a broadly-defined Harpalinae and they are also sometimes included in distinct subfamilies but a wider world view is needed to appreciate these diverse and distinctive groups and so we present them separately and remote from any particular subfamily or other group represented in the UK. More about these can be found under the following links: Odacantha melanura (Linnaeus, 1767) and Masoreus wetterhalii (Gyllenhal, 1813).