Notes on the Genus Somoplatus Dejean, 1829 (Coleoptera: Carabidae), with Descriptions of Five New Species

ABSTRACT Five new Somoplatus species, Somoplatus depilis sp. n., S. pilicollis sp. n., S. morettoi sp. n., S. ivoirensis sp. n. and S. genierorum sp. n. from Ivory Coast and Burkina Faso are described and illustrated. Paralophidius septentrionalis (Burgeon, 1936) is reinstated in the genus Somoplatus Dejean, 1829, and the new synonymy Paralophidius Basilewsky, 1986 = Somoplatus Dejean, 1829 is proposed. All specimens from the Ivory Coast were collected in abandoned termite hills in savannah habitats. One specimen of S. pilicollis sp. n. and the specimens of S. genierorum sp. n. were collected using light traps and flight interception traps in Burkina Faso. Basilewsky's key of the genus Somoplatus Dejean (Basilewsky, 1986) is updated to include the new species.


INTRODUCTION
Four new species belonging to the genus Somoplatus Dejean, 1829 were found among ground beetles collected in abandoned hills of cathedral termites in the northern parts of Ivory Coast by the entomologist and dung beetle specialist Philippe Moretto. One additional specimen of S. pilicollis sp. n. and a fifth new species, S. genierorum sp. n., were collected by François and Simon Génier in a wooded savannah habitat in Burkina Faso.
The genus Somoplatus, as revised by Basilewsky (1986), comprised eight African and one Indian species. Most collecting data of the genus indicate an association of the taxon with termite hills. However, Basilewsky reports finding some specimens in cave litter, suggesting that some species might not be strictly termitophile but rather saprophilous and hygrophilous.
In his revision Basilewsky (1986) separated a new genus, Paralophidius, which included the single species P. septentrionalis, originally described by Burgeon (1936) as Somoplatus fusciceps ssp. septentrionalis. Characters used to distinguish the new genus were the different proportions of antennomeres, the shape of the female's stylomere 2 and the shape of the elytral apex (Figs 5,13,27).
Some of the new species described below demonstrate intermediate configuration in characters of both the genera Somoplatus and Paralophidius, particularly in the proportions of the antennomeres. Stylomere 2, used by Basilewsky as an important generic character, proved to be unsuitable for separating the new genus Paralophidius: the number and position of the lateral setae is similar to Somoplatus, while the apical portion is more arcuate in Paralophidius and is proportionally shorter. Thus the genus Paralophidius, with the monotypic species Paralophidius septentrionalis, is herein regarded as a junior synonym of Somoplatus.
With the species described below, the number of species in the genus Somoplatus is now increased to 14.

MATERIAL AND METHODS
Measurements were taken and drawings were produced using a camera lucida attached to a stereomicroscope. Length was measured from the apex of the clypeus to the apex of the elytra. Width was measured at the broadest part of the elytra. The length of the pronotum was measured along the midline, the width at the broadest part of the pronotum. The genitalia were set in a transparent medium according to Lompe (1986) for drawings, and were afterwards mounted on the paper card of the related specimen with cellulose glue.
The material is deposited in the following collections: The genus Somoplatus belongs to the tribe Cyclosomini Castelnau, 1834 and subtribe Masoreina Chaudoir, 1870. All known species are fairly small (2.9-8 mm), coloured reddish brown to yellowish.
Head with large protruding eyes, two supraorbital setae; labrum transversal, bearing six setae, apical margin straight or sinuous. Proportions of antennomeres vary within the genus: short (as long as wide) to long (2.5× longer than wide). Scape glabrous with one long and a few smaller subapical setae; antennomeres 2 and 3 glabrous except a few subapical setae; antennomeres 4-11 pubescent, more or less filiform with median glabrous, glossy band on inner and outer side. Mentum with distinct tooth, bisetose. Palpi glabrous, except penultimate palpomere of labial palpi with 2 subapical setae. Terminal palpomeres fusiform, outer margin slightly more curved than inner margin. Pronotum short and wide, lateral impression inconsistent: missing, indistinct, visible in basal portions only or distinct and widened from apex to base. Lateral marginal furrow narrow; lateral margins rounded or slightly sinuate in basal half, bisetose; anterior marginal seta on anterior third, posterior marginal seta on basal angle; apex concave, apical angles protruding but rounded. Base undulate, with middle part slightly convex. Basal angles fairly distinct to completely rounded. Median line distinct. Surface of pronotum with fine microreticulation consisting of pattern of dense transversal meshes, glabrous, with extremely fine microsetae or with fine regularly seta-bearing punctation.
Elytra short and wide, oviform, subparallel-sided in the middle. Striae very shallow or absent, surface with traces of microsetae or fairly long pubescence. Microsculpture consisting of transversal, very narrow meshes. Apical truncation very indistinct: apical margin rounded to very indistinctly sinuate, sutural angle rounded. Umbilicate series of marginal setae consisting of 6 subhumeral, 3 intercalar, 4 subapical setae and one apical seta.
Legs short, outer margin of tibiae with a row of long, straight thorns. Hind tibiae with two thorns apically, inner thorn longer than half of first tarsomere. Upper side of tarsi glabrous or with sparse pubescence.
Key to species of the genus Somoplatus  (17) Stylomere 2 long, regularly arcuate (Fig. 28), apex of aedeagus long (Fig. 21) . Head: Wide, with large, protruding eyes; surface almost plain, frontal sulci shallow, subcircular, dimple-like. Surface of head with superficial fine microreticulation consisting of dense meshes and traces of highly superficial punctation. Meshes isodiametric in central portions of vertex, longitudinal and narrow along lateral portions near inner margin of eyes. Antennae long, antennomeres more than 2× longer than wide (Fig. 9). Pronotum: Short and wide, base as wide as apex; lateral margin convex in apical half, slightly more curved, widest in front of the middle; apical angles protruding, rounded off; apical margin concave; basal angles completely rounded off; base undulate, middle of base convex. Surface of pronotum with fine microreticulation of dense transversal meshes, and with very fine regularly sparse punctation. Punctation microsetose. Base and lateral apex indistinctly margined, base more distinctly margined. Marginal impression distinct, narrow near apical angle, broadly widened to the basal angles. Near basal outer margin a very small, shallow comma-shaped basal impression on either side. Middle of base slightly concave. Hind margin glabrous. Elytra: Short and wide, gently widened to the apical third, laterally subparallel. Humeri widely rounded, basal margin indistinct, almost reaching scutellum. Apical truncature indistict, apex obliquely rounded, outer angles widely rounded off. Surface of elytra glabrous, with fine microreticulation consisting of dense transversal. Fully winged. Median lobe of aedeagus: Median portion subparallel, tapering to apex, simply curved, apex ending in a short simply rounded tip, orifice large on central-left side of apical fourth (Fig. 17), inner sac with a ring of 20-25 thorns in apical third, partly with microserrulation and folds in relaxed position. Stylomere 2: Elongate, curved, outer margin with one long nematiform seta on inner margin, which is bent near the middle; one small seta on outer margin near apical fourth (Fig. 24). Lower surface: Glabrous, except for abdominal sternites with microsetae. Prosternal apophyse with 8-10 distant setae. Legs: As in generic diagnosis.   (Fig. 10). Pronotum: Short and wide, basally wider than apically, widest near middle; lateral margin regularly convex; apical angles slightly protruding, fairly distinct; apical margin concave; basal angles blunt. Surface of pronotum with fine microreticulation of dense transversal meshes and with very fine sparse setae-bearing punctation. Base, lateral margins and apex margined. Marginal impression shallow, narrow near apical angle, broadly widened to basal angles. Hind margin glabrous. Near basal outer margin a small basal impression on either side. Base undulate, middle of base slightly convex. Elytra: Short and wide, gently widened to the apical third, laterally subparallel. Humeri widely rounded, basal margin indistinct, almost reaching scutellum. Apical truncature indistict, apex oblique very gently sinuated, outer angles widely rounded off. Surface glabrous with highly superficial microreticulation, much finer than pronotal microreticulation, consisting of dense transverse meshes. Median lobe of aedeagus: Median portion subparallel, tapering to apex, simply curved, apex ending in a long acuminate tip. Apex with keel-like extension on lower side, outer tip rounded; orifice large on dorsal side (Fig. 18), inner sac without rectangular sclerotised elements.
Stylomere 2: Elongate but short, outer margin almost straight in middle portions, inner side with triangular extension bearing one foliform, apically acuminate seta, without subapical seta on outer margin (Fig. 25).  Head: Wide, with large, protruding eyes; surface almost plain, frontal sulci shallow, subcircular, dimple-like. Vertex laterally along inner margin of eyes with some weak furrows. Surface of head with superficial fine microreticulation consisting of dense meshes and highly superficial punctation. Meshes isodiametric in central portions of vertex, longitudinal and narrow along lateral portions near inner margin of eyes. Antennae long, antennomeres approximately 2× longer than wide (Fig. 11).
Pronotum: Short and wide, base slightly wider than apex; lateral margin convex in apical half, slightly sinuate in basal portions, widest in front of the middle; apical angles protruding, rounded off; apical margin concave; basal angles distinct but blunt; base undulate, middle of base convex. Surface of pronotum with fine microreticulation consisting of dense transversal meshes, with distinct, fine regularly seta-bearing punctation. Base and apex on lateral portions indistinctly margined. Margin in middle portions of apex and base broadened. Marginal impression distinct, narrow near apical angle, broadly widened to the basal angles, ending in fairly deep dimple-like, basal impression which is situated near hind margin. Hind margin glabrous. Elytra: Short and wide, gently widened to the apical third, laterally subparallel. Humeri widely rounded, basal margin indistinct, almost reaching scutellum. Apical truncature indistinct, apex oblique very gently sinuated, outer angles widely rounded off. Pubescence semidistant, long. Surface of elytra with fine microreticulation consisting of dense transversal meshes with distinct, fine, regularly seta-bearing punctation. Fully winged. Median lobe of aedeagus: Median portion subparallel, tapering to apex, simply curved, apex ending in fairly long acuminate tip, orifice large on central-left side of apical fourth, inner sac with rectangular sclerotised element in orifice, partly with microserrulation and folds in relaxed position (Fig. 19). Somoplatus fulvus Mulsant & Godart, 1867 Figs 4, 12, 20, 26 Somoplatus fulvus: Mulsant & Godart 1867: 411;Gangelbauer 1892: 396;Burgeon 1936: 307;Jeannel 1942Jeannel : 1016Basilewsky 1953Basilewsky : 10321967: 17491969: 342;1984: 32;1986: 245. (Type possibly lost.) Somoplatus marseuli Chaudoir, 1876: 7 (type in MNHN). Synonymy established by Gangelbauer (1892 Burgeon, 1936 the new species differs by the shape of the aedeagus (Fig. 21) and stylomere 2 (Fig. 28). Description: Measurements (n = 2; 1_ 1^): Length 5.0-5.1 mm, width 2.6-2.7 mm, width/length of pronotum 1.86-1.96. Colour: Uniform light reddish brown except head dark reddish brown to piceous, pubescence yellowish. Head: Wide, with large, nearly hemispheric eyes; surface almost plain, frontal sulci shallow, subcircular, dimple-like. Surface with superficial fine microreticulation consisting of dense meshes, superficial fine sparse punctation and irregular wrinkles. Meshes isodiametric in central portions of vertex, longitudinal and narrow along lateral portions near inner margin of eyes. Antennae fairly long, antennomeres approx. 1.5× longer than wide (Fig. 14). Pronotum: Short and wide, basally slightly wider than apically, widest in front of the middle; lateral margin convex, in apical half slightly more curved; apical angles slightly protruding, rounded off; apical margin concave; basal angles blunt. Surface of pronotum with fine microreticulation consisting of dense transversal meshes, which are twice as wide as long, and distinct, fine regularly seta-bearing sparse punctation. Distance between punctures twice as wide as distance between punctures on elytra. Base and lateral apex indistinctly margined, base more distinctly margined. Hind margin bearing long pubescence. Marginal impression distinct, broad near apical angle, broadly widened to the hind angles. Near basal outer margin a shallow dimple-like basal impression on either side. Base undulate, middle of base slightly convex. Pubescence distant, long. Elytra: Short and wide, gently widened to the apical third, laterally subparallel. Humeri widely rounded, basal margin indistinct, almost reaching scutellum. Apical truncature indistinct, apex obliquely rounded, outer angles widely rounded off. Surface with fine microreticulation consisting of dense transversal meshes with distinct, fine regularly seta-bearing punctation. Pubescence distant, long. Fully winged. Median lobe of aedeagus: Median portion subparallel, tapering to apex, simply curved, apex ending in a long simply rounded tip, orifice large on central-left side of apical third, no well defined inner sclerites visible, inner sac partly with microserrulation and folds in relaxed position (Fig. 21). Stylomere 2: Elongate, regularly curved, with one long straight, acute, ensiform seta on inner side, no seta on outer margin (Fig. 28).
Lower surface: Finely pubescent, pubescence fairly long. Prosternal apophyse with no distant setae but at least 4 insertion pores visible; so it is probable that the setae are broken off in both specimens. Legs: As in generic diagnosis.
Holotype: _ 'IVORY COAST, NE, Comoé National Park, v. 2000, Philippe Moretto leg., inside termite hill' (PSC). Paratype: 1^same data as holotype (PSC). Basilewsky, 1986 Figs 7, 15, 22, 29  Distribution: Guinée, Mt Nimba; Ivory Coast; Nigeria, Zaria; Democratic Republic of Congo, Garamba National Park. Remarks: The specimens from Ivory Coast have been compared to two specimens of the type series from Nigeria and the Democratic Republic of Congo. The median lobe of the aedeagus with the characteristic tongue-shaped extension covering the apial orifice and the shape of stylomere 2 of the female ovipositor were found to be similar. The only difference is in the macrosculpture of the head surface: the wrinkles between frons and orbital plates are shallow, subcircular, dimple-like in the specimens from Ivory Coast instead of deep and arcuate in the type specimens.

Somoplatus girardi
Somoplatus genierorum sp. n. Figs 8, 16, 23, 30 Etymology: Dedicated to Francois Génier and his son Simon, Canadian specialists in Scarabaeidae and collectors of the type series of this species.