Nama, Borovec, R. & Meregalli, M., 2013

Borovec, R. & Meregalli, M., 2013, Soil insect research in South Africa. 1. A new genus of terricolous weevils with four new species from the Richtersveld National Park (Coleoptera: Curculionidae: Entiminae: Trachyphloeini), Zootaxa 3646 (5), pp. 501-515 : 502-508

Nama gen. n.

Type species: Nama richtersveldiana sp. n.

Diagnosis: Small to very small Trachyphloeini , densely covered with appressed scales and some raised setae; dorso-lateral margins of rostrum sharply delimited along entire length, at base wider than space between anterior border of eyes; epistome developed; rostrum and dorsum of head capsule smoothly continuous in side view, without interruption by depression or sulcus; antennal scrobes short, directed towards eyes but not reaching them; antennal scapes robust, at apex wider than club; apex of metatibiae flattened, squamose, corbels absent; metaventral process wider than width of metacoxa, abdominal ventrites squamose, ventrite 1 longer than 2–4 combined; femora untoothed; claws free.

Description: Body length (rostrum excluded): 1.6–3.4 mm.

Body densely covered with appressed scales and raised setae. Elytra with one distinct row of setae, sometimes only on odd intervals. Setae on rostrum, head and pronotum irregularly scattered, on pronotum suberect, particularly on sides. Scapes densely squamose and setose, funicles setose, clubs tomentose. Femora and tibiae squamose with subspatulate to spatulate setae. Tarsi setose.

Rostrum very short, 1.6–2.1 times wider than long, parallel-sided or tapered anteriad. Dorsum wide and short, with sharp lateral margins along entire length, at base wider than space between anterior border of eyes, with Ushaped or simple, narrow longitudinal furrow. Frons wide, squamose or, in N. pentamera , glabrous. Epistome distinct, separated from frons by very narrow V-shaped keel. Antennal scrobes in dorsal view invisible or visible only in apical half, in lateral view short, not reaching eyes, with ventral border curved, directed to ventral margin of eye and dorsal border directed to or above dorsal border of eye. Eyes small, without subocular fringe. Vertex flat, without fovea. Temples in lateral view with fine longitudinal striae, at least below eyes, in N. pentamera without striae.

Antennal scapes robust, reaching anterior border of pronotum, 1.3–1.5 times longer than funicles; in basal part curved or S-shaped, widened apicad, in apical part robust, widest at apex and here 4–5 times wider than at base, wider than club or protibia at midlength. Funicles slender, 5- or 7-segmented. Clubs slender, spindle-shaped, first segment as long as or slightly longer than segments 2 and 3 combined, annulus of segment 3 visible.

Pronotum 1.3–1.7 times wider than long, sides arcuate, constricted behind anterior margin, anteriorly narrower than posteriorly, occasionally with a dorsal fringe of setae. Disc regularly and weakly convex, without any differentiated sculpture. Lateral part of anterior border without postocular lobes and lacking a fringe of setae. Procoxal cavities contiguous; procoxae semiglobular, situated near anterior border of pronotum but not reaching it.

Scutellum entirely concealed.

Elytra oval to elongate-oval, 1.3–1.5 times longer than wide, with regularly rounded humerus, sides parallel or curved, in lateral view flat or convex. Striae very narrow, intervals wide, all almost flat. First stria at base curved towards outside, sutural interval widened at base, only in N. pentamera first stria straight at base. Mesocoxae semiglobular, mesoventral process slightly wider than one-fifth of mesocoxal width.

Femora of all legs untoothed. Protibiae with apex rounded, without lobes and indentations, armed with strong or fine spines or with a fringe of fine setae and a strong mucro. Meso- and metatibiae mucronate. Apex of metatibiae flattened, densely squamose, corbels absent. Tarsi short or slender; segment 3 distinctly wider than 2, deeply bilobed; 5 distinctly exceeding 3. Claws free.

Ventrite 1 longer than ventrites 2–4 combined. Ventrite 2 in middle as long as or longer than ventrite 3 or 4. Suture between 1 and 2 fine, arcuate with arch directed posteriad or straight, other sutures deep and broad. Ventrites densely squamose. Metaventral process obtuse, very wide, distinctly wider than width of metacoxa.

Male genitalia. Penis parallel-sided along most of its length, short and very feebly sclerotised, only in apical part rounded or tapered. Temones 2.0–2.4 times longer than body. Tegmen without parameres, ring very narrow, temones 3.3–4.2 times longer than tegminal manubrium. Sternite IX with spiculum gastrale moderately long, anteriorly curved and tapered, posteriorly with fused basal arms; apical plate absent. Endophallus with two long, slender, cylindrical sclerites and a long ventral slender process, in N. pentamera without sclerites.

Female genitalia. Sternite VIII with spiculum ventrale slender, 2.7–4.0 times longer than plate, at apex with indistinct caput, at base fully extending into plate almost to its apex; plate small, oval or triangular, with indistinctly delimited basal margin and with very narrow apical margin, translucent or sclerotised in the middle. Gonocoxites flat, triangular, tapered apicad, translucent, with apical cylindrical stylus bearing setae. Spermatheca C-shaped, with developed cornu, ramus and nodulus, straight ramus usually longer and wider than curved nodulus.

Reproduction. All the known species are sexually reproducing.

Sexual dimorphism. Not apparent in morphological characters.

Distribution. The genus as known so far occurs only in the north-western part of South Africa.

Etymology. The genus is named after the Nama people, an ethnic group of South Africa, Namibia and Botswana. They are the largest group of the Khoikhoi people, most of who have largely disappeared as a group, and the Richtersveld Community Conservancy is their last refuge (Wikipedia contributors, 2012b). The genus name is feminine in gender.

Included taxa. Four species, here described as new, are presently known.

Differential diagnosis and discussion. Nama gen. n. is included in the tribe Trachyphloeini by the presence of the following set of characters:

- dorsal part of rostrum with well-defined borders along entire length, at base as wide as space between the anterior borders of eyes

- epistome developed

- antennal scrobes placed dorsally, furrow-shaped in lateral view

- rostrum distinctly wider than long, dorsally not separated from head by a sharp, narrow, V-shaped transverse sulcus

- elytra without developed humeri

- entire dorsal part of the body densely covered with appressed scales

- all femora untoothed

- metatibiae without corbels, obliquely flattened at apex.

Nama differs from the only other genus of Trachyphloeini thus far described from the South African region, Pentatrachyphloeus , in the following characters: claws free (connate in basal half in Pentatrachyphloeus ), metaventral process distinctly wider than width of metacoxa (at most as wide in Pentatrachyphloeus ) and ventrite 1 distinctly longer than ventrites 2–4 combined (as long as in Pentatrachyphloeus ).

The new genus resembles the Palaearctic trachyphloeine genera Cathormiocerus Schoenherr, 1842 , Trachyphloeus Germar, 1817 and Romualdius Borovec, 2009 in having the anterior margin of the pronotum straight, without postocular lobes, lateral fringe of setae and claws free. However, Nama differs from Cathormiocerus by having all claws free in the male (connate in the fore and middle tarsi in males of Cathormiocerus ), the ventrites covered with matt scales (glossy scales in Cathormiocerus ), the scrobes not reaching the eyes (at least ventral border reaching eyes in Cathormiocerus ), the suture between ventrites 1 and 2 straight or arcuate posteriad (suture sinuose and arcuate anteriad in Cathormiocerus ) and ventrite 1 longer than ventrites 2–4 combined (shorter in Cathormiocerus ). Nama is easily distinguished from Trachyphloeus by the following characters: protibiae without apical lobes and indentations (with lobes and indentations in Trachyphloeus ), spiculum ventrale loosely connected to plate of sternite VIII, plate without a sharply delimited basal margin (distinctly connected to plate in a Y-shape, plate thus with a distinct basal margin in Trachyphloeus ), metaventral process distinctly wider than width of metacoxa (at most as wide in Trachyphloeus ), ventrite 1 longer than ventrites 2–4 combined (shorter in Trachyphloeus ), suture between ventrites 1 and 2 straight or arcuate posteriad (sinuose, arcuate anteriad in Trachyphloeus ). Nama is easily distinguished from Romualdius in having the rostrum dorsally not separated from the head (separated by a shallow, transverse impression in Romualdius ), the sutures between ventrites 2 and 5 straight (feebly arcuate in Romualdius ), the metatibiae without corbels (with corbels in Romualdius ), the metaventral process distinctly wider than width of metacoxa (at most as wide in Romualdius ), ventrite 1 longer than ventrites 2–4 combined (shorter in Romualdius ) and sternite VIII in the female feebly sclerotised, flat, with apical setae (strongly sclerotised, longitudinally folded along spiculum ventrale, without setae in apical part in Romualdius ).

Description of the new species of Nama

Nama richtersveldiana sp. n. Figs 1–10 , 41, 45, 49, 53 .

Holotype: 3, South Africa, Northern Cape, Richtersveld National Park, 5.5 km N of Helskloof Pass, 28°17.211'S 16°59.378'E, 22.ix. 2012, 570 m, M. Meregalli lgt. (TMSA).

Paratypes: same data as holotype, 12 exx. (10 MER, 2 BOR); same locality, 2.xi.2011, 1 3 1 Ƥ, M. Meregalli lgt. (BOR).

Description: Body length (rostrum excluded): 2.69–3.43 mm, holotype 3.19 mm.

Appressed scales on entire body rounded, finely longitudinally striate, very dense, completely hiding integument. Elytral intervals with one moderately dense row of semi-erect, subspatulate setae, slightly shorter than half one interval width. Pronotum with similar semi-erect setae, irregularly scattered on disc, on sides erect and strongly prominent. Rostrum and head with short, inconspicuous, irregularly placed semi-erect setae. Elytra with dark brownish to blackish scales and yellow-greyish scales forming numerous irregular small spots, in several specimens elytra almost entirely yellow-greyish. Pronotum with two longitudinal yellow-greyish stripes, rostrum paler than head.

Rostrum very short, 1.8–2.0 times wider than long, at apex as wide as at base, with slightly concave sides. Dorsum from base to apex feebly widened, with slightly concave sides, wide, flat, with distinct, very narrow Ushaped furrow, extending from between antennal insertions to posterior edge of eyes. Frons not separated from epifrons, densely squamose. Antennal scrobes in dorsal view invisible, in lateral view short, strongly widened posteriad, ventral border feebly curved, almost reaching bottom edge of eye, dorsal border straight, parallel to dorso-lateral margin of rostrum, directed above eye. Rostrum and head in lateral view flat, with straight dorsal border. Eyes small, convex, in dorsal view moderately prominent, in lateral view placed in dorsal half of head. Head wide, in dorsal and ventral view significantly tapered anteriad. Vertex large, flat. Temples in lateral view longitudinally striate below and above eye, above eye concealed by scales.

Scapes very slender in basal third, distinctly S-shaped, robust in apical two-thirds, gradually widened apicad, at apex 1.6 times wider than club and 1.5 times wider than middle of protibia. Funicles with segment 1 1.6–1.8 times longer than wide and 1.5–1.7 times longer than segment 2, which is 1.7–1.9 times longer than wide; segments 3 and 4 1.3–1.5 times longer than wide, segment 5 1.2–1.3 times longer than wide, segment 6 1.1–1.2 times longer than wide, segment 7 as long as wide. Clubs slender, 2.2–2.3 times longer than wide, segment 1 as long as segments 2+3 combined.

Pronotum transverse, 1.6–1.7 times wider than long, widest at basal third, sides strongly rounded, distinctly constricted behind anterior margin; base arcuate; in lateral view almost flat.

Elytra long, 1.4–1.5 times longer than wide, parallel-sided, base arcuate, apically broadly rounded, in lateral view flat. Striae very narrow, intervals wide, almost flat; first stria curved laterad at base, sutural interval widened at base.

Protibiae moderately long, apex slightly widened laterally and mesally, rounded, armed with 6 distinct, yellowish spines and one long mucro. Tarsi slender, very long; segment 2 1.1 times wider than long; segment 3 1.2–1.3 times wider than long and 1.7–1.8 times wider than 2; segment 5 long, gradually widened apicad, 3.0 times longer than wide, 2.1–2.2 times longer than previous one, at apex as wide as segment 2. Claws long.

Ventrites densely squamose, 1.1–1.2 times longer than wide. Ventrite 1 in middle longer than ventrites 2–5 combined; ventrite 2 half as long in middle than at sides, in middle as long as ventrite 3 or 4. Ventrite 5 apically subtruncate. Suture between ventrites 1 and 2 fine, deeply arcuate anteriad; other sutures straight, deep and broad.

Penis short and wide, 1.6 times longer than wide, widest at base and regularly tapered apicad with straight sides, apex approximately triangular.

Female genitalia. Sternite VIII with apodeme slender, 2.7–2.9 times longer than plate, extending into plate, dividing at basal part of plate into parallel-sided arms extending almost along to apex of plate. Caput small, indistinct. Plate small, oval, narrowed basad and apicad, more sclerotised in the middle, translucent at circumference. Gonocoxites flat, triangular, translucent, tapered apicad, with apical cylindrical setose stylus. Spermatheca with slender and curved cornu, large body and straight, robust ramus, twice as long as and wider than nodulus.

Habitat. All the specimens were sifted from debris and dead leaves below chenopodioid shrubs ( Amaranthaceae ).

Etymology. This species is named after the Richtersveld.

Differential diagnosis. This is the largest species of the genus, easily distinguished also by the distinct Ushaped furrow on the rostrum, the invisible antennal scrobes in dorsal view, the elongate funicle segments 3 and 4 (1.3–1.5 times longer than wide), the strongly transverse pronotum (1.6–1.7 times wider than long), and the deeply arcuate suture between ventrites 1 and 2.

Nama pentamera sp. n.

Figs 11–20 , 42, 46, 50, 54 .

Holotype: 3, South Africa, Northern Cape, Richtersveld National Park, mountain S of Helskloof Pass, 28°21.416'S 16°58.899'E, 815 m, 22.ix.2012, M. Meregalli lgt. (TMSA).

Paratypes: same data as holotype,16 exx. (12 MER, 4 BOR); South Africa, Northern Cape, Richtersveld National Park, 5.5 km N of Helskloof Pass, 28°17.211'S 16°59.378'E, 22.ix. 2012, 570 m, 2 exx., M. Meregalli lgt. (MER).

Description: Body length (rostrum excluded): 1.63–1.91 mm, holotype 1.78 mm.

Entire body covered with irregular, star-shaped appressed scales with five raised tips and a small impression in the middle, scales scarce, distance between two scales about as wide as diameter of a scale. Elytra with setae only on odd intervals, setae dense, semi-erect, spatulate, about as long as half one interval width. Setae on pronotum and head including rostrum similar to those on elytra, irregularly scattered, on side erect, strongly prominent. Scales and setae uniformly greyish or pale brownish on entire surface.

Rostrum short, 1.6–1.8 times wider than long, parallel-sided. Dorsum strongly tapered anteriad, with linear sides, flat, with a very narrow median longitudinal furrow, extending along the entire length and reaching anterior margin of pronotum. Frons glabrous, short. Antennal scrobes in dorsal view visible in apical two thirds, in lateral view short, curved, triangle-shaped, dorsal and ventral border distinctly curved, respectively directed towards dorsal and ventral margin of eye but not reaching it. Scrobes separate from eye by a glabrous stripe. Rostrum in lateral view convex, frons oblique. Eyes small, distinctly convex, prominent. Eyes in lateral view placed in lower half of head. Head short, sides convergent anteriad. Vertex broad, moderately convex. Temples in lateral view without longitudinal striae.

Scapes short, robust, extremely thickened, curved at midlength, basal half narrow, straight, apical two/thirds irregularly and abruptly widened, maximum width before apex, 1.2 times wider than club and only 1.1 times wider than middle of protibia. Funicles with segment 1 conspicuously bigger than segment 2, 1.7–1.8 times longer than wide and 1.7–1.9 times longer than segment 2, which is 1.9–2.1 times longer than wide, segment 3 1.1 times longer than wide, segment 4 as long as wide, segment 5 1.1 times wider than long. Clubs oval, much bigger than segments 2–5, 1.5–1.6 times longer than wide, first segment slightly longer than segments 2 and 3 combined.

Pronotum 1.3–1.4 times wider than long, maximum width behind midlength, slightly constricted behind anterior margin, sides distinctly rounded, base straight; in lateral view feebly convex in basal half, slightly impressed in apical half. Anterior margin in lateral view obliquely directed towards underside.

Elytra elongate–oval, 1.4 times longer than wide, with parallel sides, broadly rounded apicad, in lateral view almost flat, base straight. Striae hardly visible, hidden by appressed scales, intervals flat.

Protibiae short and robust, widest at basal third, tapered to apex. Apex with a fringe of fine, yellowish setae, lateral and mesal edge straight, not widened, with one conspicuously long and strong mucro. Tarsi short, segment 2 1.5 times wider than long; segment 3 1.2–1.3 times wider than long and 1.2–1.3 times wider than segment 2. Tarsomere 5 distinctly widened apicad, 2.2–2.3 times longer than wide, 1.6–1.7 times longer than segment 3, at apex narrower than segment 2.

Ventrites densely squamose, 1.21–1.25 times longer than wide. Ventrite 2 slightly longer than ventrites 2–4 combined. Ventrite 2 shorter in middle than at sides, in middle about as long as ventrite 3. Ventrite 5 rounded at apex. Suture between ventrites 1 and 2 fine, shallowly arcuate posteriad; other sutures straight, deep and broad.

Penis along entire length approximately parallel-sided, 1.8–2.2 times longer than wide, with slightly concave sides, apex abruptly tapered to a small triangular point.

Female genitalia. Sternite VIII with apodeme moderately long, slender, widest at plate base and tapered towards an indistinct caput, 2.8–3.2 times longer than plate, terminating inside plate and almost reaching apical border of plate. Plate triangular, constricted, with obtuse apex and a distinct concavity before it, with a narrow but distinct basal border, translucent in apical half. Gonocoxites flat, triangular, translucent with sclerotised external borders, tapered apicad, pointed, styli apical, cylindrical, setose. Spermatheca with long and slender curved cornu, broadened towards nodulus, ramus and nodulus equally long and wide, deflected, ramus straight, nodulus feebly curved.

Habitat. The specimens from the mountain south of the Helskloof pass were sifted from below and at the edges of large and flat stones and underneath Mesembryanthemoideae (Aizoaceae) shrubs, amidst detritus and dry soil litter.

Etymology. The specific epithet refers to the 5-segmented antennal funicles and is composed of the Greek words penta (five) and meros (segment, part).

Differential diagnosis. This species is very easily distinguished from all the other species of the genus by its small size, the peculiar antennae, with a very thick antennal scape, the 5-segmented funicles, the broadly oval clubs, the elytra with raised setae only on odd intervals, the sparse, star-shaped appressed scales, the dorsum of the rostrum strongly tapered anteriad, with straight sides, the glabrous frons, the temples lacking longitudinal striae, the straight base of pronotum and elytra, the short and robust protibia, widest at basal third and tapered to apex, the apically rounded ventrite 5, the shallowly arcuate suture between ventrites 1 and 2, the abruptly tapered apex of the penis and the female sternite VIII with constricted, triangular plate.

Figures

FIGURES 1 – 10. Nama richtersveldiana n. sp., paratype. Body (1, 2); elytra (3); rostrum, dorsal (4), dorso-lateral (5), lateral (6); pronotum (7); apex of fore tibia (8); ventrites (9); antenna (10). Bar: 1 mm.

FIGURES 41 – 56. Nama richtersveldiana n. sp., paratype. Sternum VIII of female (41); gonocoxites (45); spermatheca (49); aedagus (53). Nama pentamera n. sp., paratype. Sternum VIII of female (42); gonocoxites (46); spermatheca (50); aedagus (54). Nama iuliae n. sp., holotype, paratype. Sternum VIII of female (43); gonocoxites (47); spermatheca, fragment (51); aedagus (55). Nama erikae n. sp., paratype. Sternum VIII of female (44); gonocoxites (48); spermatheca (52); aedagus (56). Bars: Fig 53: 500 Μm; figs 41 – 48, 54 – 56: 250 Μm; figs 49 – 51: 100 Μm

FIGURES 11 – 20. Nama pentamera n. sp., paratype. Body (11, 12); elytra (13); rostrum, dorsal (14), dorso-lateral (15), lateral (16); pronotum (17); fore tibia (18); ventrites (19); antenna (20). Bar: 1 mm.