Epistomius niger, 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: 669-671

publication ID

http://doi.org/ 10.1515/aemnp-2017-0094

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scientific name

Epistomius niger

sp. nov.

Epistomius niger   sp. nov.

( Figs 2G–I View Fig , 3F View Fig , 10A–G View Fig )

Type locality. South Africa, KwaZulu-Natal, Ongoye Forest Reserve, 28°50.6′S, 31°40.1–2′E.

Type material. HOLOTYPE: 1 ♂, ‘ South Africa, KwaZulu-Natal, Ongoye Forest Reserve , 28°50.6′ S 31°40.1-2′ E, 11.i.2016, Berlese extraction, leaf & log litter, sifting, J. Janák lgt.’ ( TMSA)   . PARATYPES: 24 ♂ ♀, the same data as holotype ( JJRC, JSPC, NMPC, RBSC)   ; 4 ♂ ♀, ‘RSA [ South Africa], KwaZulu-Natal, Ongoye Forest, Birders Lodge , 280 m, 2.-6.XII.2010, leg. D. Bartsch & J. Berg’ ( SMNS)   ; 69 ♂ ♀, ‘ S. Afr. [ South Africa], KWZ Natal [KwaZulu-Natal], Ongoye Forest , 294 m, 4.- 5.12.2010, 28.50 S – 31.44 E, E-Y: 3890, sifting forest litter, leg. Ruth Müller’ ( TMSA) GoogleMaps   . Additional material examined. 14 ♂ ♀, ‘ South Africa, KwaZulu-Natal, Entumeni Nature Reserve, 28°53.2′ S 31°22.6′ E, 11.i.2016, J. Janák lgt.’ ( JJRC, RBSC).

Description ( Figs 2G–I View Fig , 10A–G View Fig ). Body length 1.71–2.31 mm, holotype 1.75 mm. Body blackish, basal two thirds on antennal scape, funicle and short apical part of tibiae reddish brown, tarsi yellowish brown. Elytra, pronotum and head with rostrum sparsely covered with appressed oval to drop-shaped scales, 3–4 across width of one interval, leaving between scales distance only slightly shorter than width of one scale. Appressed scales on femora and tibiae identical to elytral ones but smaller. Setae on basal half of elytra semiappressed, short, inconspicuous, on apical half erect, conspicuous, slender, widest at midlength, narrowly apically rounded, only slightly shorter than width of one interval, distance between two setae on posterior declivity more than twice as long as length of one seta. Setae on pronotum and head with rostrum subspatulate, short, about equal to those of basal half of elytra, semiappressed, hardly prominent in lateral view. Scape, femora and tibiae with short, long-oval semiappressed setae, hardly prominent from outline. Scales and setae light greyish brown.

Head ( Figs 10A–D View Fig ). Rostrum in males ( Fig. 10B View Fig ) extremelly enlarged in apical half, apical part distinctly prominent laterally, 1.15–1.19× as wide as long, at apex 1.17–1.19× as wide as at base and 0.9× as wide as head including eyes; in females ( Fig. 10C View Fig ) evenly weakly enlarged apicad with weakly concave sides, 1.06–1.08× as wide as long, at apex 1.04–1.08× as wide as at base, 0.8× as wide as head including eyes. Epifrons with weakly concave sides, when cleared of scales shiny, smooth, unpunctured, with deep and well developed longitudinal median stria reaching to middle of vertex and with two inconspicuous lateral longitudinal keels. Frons deepened, smooth. Epistome in males distinctly wider than width of epifrons at midlength, in females narrower, only slightly wider than epifrons at midlength. Head when cleared of scales shiny and smooth, with several very fine, almost indistinct longitudinal striae. Eyes convex, somewhat prominent from outline of head.

Antennae ( Fig. 10A View Fig ). Antennal scape 5.8–6.1× as long as wide and 1.5–1.6× as long as funicle, at apex 0.8× as wide as club. Funicle segment I 1.6–1.7× as long as wide and twice as long as segment II, which is 1.1–1.2× as long as wide; segments III–VI 1.3× as wide as long; segment VII 1.4–1.5× as wide as long. Club 1.6–1.7× as long as wide.

Pronotum ( Fig. 10A View Fig ) in males 1.43–1.49× as wide as long, in females 1.35–1.39× as wide as long, widest behind midlength, with rounded sides, more tapered anteriad than posteriad, constricted behind anterior margin. When cleared of scales regularly convex, shiny, densely coarsely punctured, with 6–7 punctures along the length, punctures large, distance of punctures shorter than their semidiameter. Pronotum in lateral view weakly convex, behind anterior border lowered.

Elytra ( Fig. 10A View Fig ) in males short, globular, 1.09–1.11× as long as wide, in females longer, oval, 1.16–1.19× as long as wide.

Legs ( Figs 10A, E View Fig ). Tarsomere II 1.6–1.7× as wide as long; tarsomere III 1.5× as wide as long and 1.3× as tarsomere II; onychium 1.9–2.1× as long as tarsomere III.

Male genitalia ( Figs 3F View Fig , 10G View Fig ). Penis short, weakly longer than wide, widest at base, slightly evenly tapered apicad, apex subtriangular; in lateral view weakly irregularly curved, equally wide, tapered only at apex, with slender lengthened tip.

Variability ( Figs 2G–I View Fig ). Typical population from Ongoye has elytral setae on apical declivity slender, widest at midlength, apically shortly rounded, slightly shorter than width of one interval, while population from Entumeni has the same setae lancet-shaped, narrower, sharply apically pointed, weakly longer than width of one interval. The material from Entumeni was not included in the type series to conserve the typical characters (see the variability chapter in Epistomius   description).

Etymology. The blackish colour of antennae, legs and integument suggested the Latin name of this new species.

Biology. The type specimens were sifted from leaf litter in native broad-leaved forest.

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

Differential diagnosis. Epistomius niger   sp. nov. is by conspicuously enlarged rostrum and globular elytra in males similar to E. bulirschi   sp. nov., from which it can be easily distinguished by erect setae on posterior declivity, in males also by penis not enlarged in apical third and in females by rostrum weakly enlarged apicad with epistome wider than epifrons at midlength. In view of the variability of elytral erect setae it could be confused mainly with E. colonnellii   sp. nov. as it has similar shape of setae and rostrum in males distinctly enlarged apicad, but it is distinguishable mainly by slenderer tibiae and tarsi with longer onychium, blackish antennal funicle and penis 1.6–1.7× as long as wide, tapered apicad with small tip, while E. colonnellii   sp. nov. has penis shorter and wider, 1.3–1.4× as long as wide, parallelsided, apically obtuse.


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National Museum Prague


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