Epistomius ngomiensis, Borovec & Skuhrovec, 2017

Borovec, Roman & Skuhrovec, Jiří, 2017, Epistomius, a new genus of African forest litter Trachyphloeini, with descriptions of seven new species (Coleoptera: Curculionidae: Entiminae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 57 (2), pp. 645-676 : 666-669

Epistomius ngomiensis sp. nov.

( Figs 3E , 9A–G )

Type locality. South Africa, KwaZulu-Natal, Ngome State Forest, 27°49.3′S, 31°25.0′E, 1150 m a.s.l.

Type material. HOLOTYPE: ♂, ‘ South Africa: KZN [KwaZulu-Natal], Ngome State Forest, 27°49.3′ S 31°25.0′ E, 18.ix.1992 - 18.x.1992, 1150m, Unbaited pitfall trap in dense afromontane indigenous forest, Ngome Arthropod Survey, University of Pretoria , Sample 10/92-3A, M.v.d. Merwe [lgt.]’ ( SANC) . PARATYPES: 1 ♂, the same data as holotype ( SANC) ; 1 ♂, the same data as holotype, but ‘ 27°50.1′ S 31°25.5′ E, 1010m, Sample 10/92-2B’ ; 1 ♂, the same data as holotype, but ‘ 27°50.1′ S 31°25.5′ E, 18.vii.1992 - 18.viii.1992, 1010m, Sample 08/92-2B’ ; 4 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.4′ E, 18.i.1992 - 18.ii.1992, 1100m, Sample 02/92-2D’ ; 2 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.2′ E, 17.xii.1992 - 16.i.1993, 1130m, Sample 01/93-2A’ ; 1 spec., the same data as holotype, but ‘ 27°50.1′ S 31°25.5′ E, 18.viii.1992 - 18.ix.1992, 1010m, Sample 09/92-2B’ ; 2 spec., the same data as holotype, but ‘ 18.x.1992 - 18.xi.1992, 1150m, Sample 11/92-3A’ ; 1 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.2′ E, 18.ix.1992 - 18.x.1992, 1130m, Sample 10/92-2A’ ; 1 spec., the same data as holotype, but ‘ 27°49.4′ S 31°25.7′ E, 17.xii.1992 - 16.i.1993, 1140m, Sample 01/93-4B’ ; 1 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.4′ E, 18.x.1992 - 18.xi.1992, 1100m, Sample 11/92-2D’ ; 1 spec., the same data as holotype, but ‘ 27°50.5′ S 31°25.2′ E, 18.viii.1992 - 18.ix.1992, 1040m, Sample 09/92-2C’ ; 2 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.2′ E, 18.xi.1992 - 17.xii.1992, 1130m, Sample 12/92-2A’ ; 1 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.2′ E, 18.viii.1992 - 18.ix.1992, 1130m, Sample 09/92-2A’ ; 1 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.4′ E, 18.vii.1992 - 18.viii.1992, 1100m, Sample 08/92-2D’ ; 1 spec., the same data as holotype, but ‘ 18.vii.1992 - 18.viii.1992, Sample 02/92-2D’ ; 3 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.7′ E, 17.vi.1992 - 18.vii.1992, 1140m, Sample 07/92-4A’ ; 2 spec., the same data as holotype, but ‘ 27°49.5′ S 31°25.7′ E, 18.xi.1992 - 17.xii.1992, 1140m, Sample 12/92-4A’ ; 2 spec., the same data as holotype, but ‘ 27°49.4′ S 31°25.8′ E, 17.xii.1992 - 16.i.1993, 1110m, Sample 01/93-4C’ ; 1 spec., the same data as holotype, but ‘ 27°49.4′ S 31°25.7′ E, 14.ii.1994 - 15.iii.1994, 1140m, Sample 03/94-4B, R. Stals [lgt.] ’; 2 spec., the same data as holotype, but ‘ 27°49.4′ S 31°25.0′ E, 18.viii.1993 - 18.ix.1993, 1140m, Sample 09/93-3B, R. Stals [lgt.] ’; 1 spec., the same data as holotype, but ‘ 18.viii.1992 - 18.ix.1992, 1150m, Sample 09/92-3A’ (all SANC) ; 7 ♂ ♀, ‘ South Africa, KwaZulu-Natal, Ngomi Forest , 27°51′ S, 31°23′ E, 24.-27.xi.2006, J. Janák lgt.’ ( JJRC, JSPC, RBSC) ; 120 ♂ ♀, ‘ S. Afr. [ South Africa, Kwa- Zulu-Natal], Zulu Drakensbg, Ngome tourist camp, 25.2.1997, 27.49 S – 31.25 E, E-Y: 3286, sifted indig. forest, leg. Endrödy-Younga’ ( TMSA) ; 27 ♂ ♀, ditto, but ‘ 20.2.1997, 27.50 S – 31.24 E, E-Y: 3289’ ( TMSA) .

Description ( Figs 9A–G ). Body length 1.72–1.97 mm, holotype 1.88 mm. Body dark brownish to blackish, antennae and tarsi paler, reddish brown to dark brownish, apical part of scape sometimes darker. Elytra with moderately sparse appressed scales, subtriangular, owned apicad, with projecting bristle, 3–4 across width of one interval, distance between them about half diameter of one scale. Pronotum and head with rostrum with dense subcircular scales, with fine fan-shaped striae, creating short, fine and dense fringes on almost half of circumference, almost covering integument; lateral parts of pronotum with scales half star-shaped, with long sparse fringes. Appressed scales on scape, femora and tibiae similar to pronotal ones, slightly smaller. Erect setae on elytra very varying, with shape from lancet-shaped to subspatulate or even spatulate, with length equal to width of one interval or longer, but having all other characters uniform, this seems to be highly variable within species; setae weakly shorter on anterior third than on posterior declivity, creating one regular row on each interval, in some species intervals 2 and 4 with very sparse setae. Pronotum and head with rostrum with semierect subspatulate setae similar to those on anterior part of elytra but shorter, irregularly scattered, setae on interocular space twice as long as the others. Scape, femora and tibiae with short, long-oval, semiappressed setae, densely irregularly scattered, hardly visible, not prominent from outline. Body vestiture light brownish, raised setae paler, greyish brown.

Head ( Figs 9A–D ). Rostrum in males ( Fig. 9B ) distinctly tapered in basal half and enlarged in apical half, with concave sides and subparallel-sided in females ( Fig. 9C ), slightly tapered in basal half and indistinctly enlarged in apical half, rounded around scrobes, in males 1.09–1.12× as wide as long, at apex as wide as at base; in females 1.16–1.25× as wide as long, at base 1.04–1.09× as wide as at apex, in both sexes distinctly narrower than head including eyes. Epifrons with slender longitudinal median stria, when cleared of scales shiny, shallowly deepened with several fine punctures, with short slender longitudinal median stria on basal half and with two very slender subparallel keels along whole length. Frons deepened, finely rough. Epistome in males wide, wider than epifrons at midlength, in females narrow, equally wide as epifrons at midlength. Head when cleared of scales shiny, distinctly convex, with small fovea and slender median longitudinal stria on apical half, with only several very slender and short striae and punctures mainly on anterior part and along eyes. Eyes weakly prominent from outline of head.

Antennae ( Fig. 9A ). Antennal scape 5.8–5.9× as long as wide and 1.5–1.6× as long as funicle, club 1.1–1.2× as wide as scape at apex. Funicle segment I 1.7–1.8× as long as wide and 1.7–1.8× as long as segment II, which is 1.3–1.4× as long as wide; segments III–V 1.5× as wide as long; segment VI 1.3–1.4× as wide as long; segment VII 1.2× as wide as long. Club 1.8–1.9× as long as wide.

Pronotum ( Fig. 9A ) in males 1.38–1.43×, in females 1.41–1.52× as wide as long, widest at about midlength, with distinctly rounded sides. When cleared of scales regularly convex, moderately shiny, irregularly sparsely and coarsely punctured, punctures shallow, with small ring inside, distance between two punctures shorter than diameter of one puncture, pronotum with anterior border reddish, bordered by tranverse dense row of fine punctures. Pronotum in lateral view almost flat, lowered behind anterior border.

Elytra ( Fig. 9A ) in males 1.22–1.27×, in females 1.26–1.29× as long as wide.

Legs ( Figs 9A, E ). Tarsomere II 1.6–1.7× as wide as long; tarsomere III 1.3–1.4× as wide as long and 1.2–1.3× as wide as tarsomere II; onychium 1.5× as long as tarsomere III.

Male genitalia ( Figs 3E , 9G ). Penis longer than wide, slender, subparallel-sided, with regularly subtriangular apex.

Etymology. Patronymic, species is named after the Ngome forest, where an extensive material of the new species was collected.

Biology. The majority of the material was collected in unbaited pitfall traps in dense afromontane native forest, whereas a smaller part was sifted from forest litter.

Distribution. South Africa: KwaZulu-Natal ( Fig. 4 ).

Differential diagnosis. The species is hardly distinguishable with varying shape and length of the raised elytral setae, but distinctly recognisable by appressed elytral scales awned, with projecting bristles, rostrum in males distinctly tapered in basal half and enlarged in apical half, with concave sides and subparallel-sided in females; and penis long and slender, without tip at apex. This set of characters easily distinguishes E. ngomiensis sp. nov. from all other species of the genus.

Figures

Fig. 3. Apex of penis.A – Epistomius bulirschi sp. nov.; B – Epistomius colonnellii sp. nov.; C – Epistomius janaki sp. nov.; D – Epistomius natalensis sp. nov.; E – Epistomius ngomiensis sp. nov.; F – Epistomius niger sp. nov.; G – Epistomius wanati sp. nov.

Fig. 9. Epistomius ngomiensis sp. nov. A – habitus, dorsal view, holotype, male; B – rostrum, male, dorsal view; C – rostrum, female, dorsal view; D – rostrum, male, lateral view; E – protibia, male; F – spermatheca; G – aedeagus. Scale bars: 1 mm (A), 0.5 mm (G) and 0.2 mm (F).

Fig. 4. Distribution of Epistomius species in South Africa; Epistomius bulirschi sp. nov. (yellow circle); Epistomius colonnellii sp. nov. (brown circles); Epistomius janaki sp. nov. (violet circles); Epistomius natalensis sp. nov. (blue circles); Epistomius ngomiensis sp. nov. (red circles); Epistomius niger sp. nov. (green circles); and Epistomius wanati sp. nov. (orange circle).