Phoberus villeti Strümpher, 2023

Strümpher, Werner P., 2023, A new flightless species of Phoberus Macleay, 1819 (Coleoptera: Trogidae) from the Eastern Cape Province in South Africa, Zootaxa 5264 (1), pp. 143-150 : 144-146

Phoberus villeti Strümpher , new species

( Figs. 1–5 )

Type locality. “ SOUth AfrIca, Eastern Cape PrOvInce, HOgsback [ AmathOle DIstrIct ], 32°35′51.15″S 26°57′31.87″E ” .

Type material examined. South Africa, Eastern Cape Province. Holotype ♀ ( ALBM, specImen cleaned) ( Figs. 1–4 ): “ SOUTH AFRICA: Eastern Cape | PrOv., HOgsback, 02.v.2010, | 32°35′51.15″S 26°57′31.87″E | leg. G. van Heerden ” || “HOLOTYPE | Phoberus villeti | det. W.P. Strümpher 2023 ”.

Description of holotype (♀). Size. Length: 11.9 mm. Width: 5.0 mm.

Body shape. Strongly convex, oval; elytral profile convex, maximum height in the middle.

Colour ( Figs. 1–3 ). Matt black. Surface of head, parts of pronotum, and ventral aspects with light brown tomentose coating. Body setae mostly yellowish brown to brown.

Head ( Figs. 1–3 ). Clypeus obtusely triangular, disc slightly elevated, feebly convex, tubercles or ridges absent, apex of clypeus with apical portion downward and rounded, margin slightly reflexed, entire; surface coarsely sculpted with discrete round to irregularly shaped punctures; punctures close, large, each with a short stout seta, surface between punctures tomentose. Clypeogenal and frontoclypeal sutures distinctly raised; frontoclypeal suture complete, with a low indistinct clypeogenal tubercle on either side, tubercles punctate. Frons raised, with paired, setose carinae, separated by a distinct, raised median ridge, setose carinae on frons marked by row of long, erect, stout seta; surface coarsely sculpted with distinct round punctures. Genal angles obtuse; genae shape rounded, narrow; genal surface depressed with discrete and irregularly shaped punctures; genal margin with distinct row of long erect setae. Vertex densely and evenly covered with round punctures, punctures placed close together, central vertex distinctly elevated, marked by two central tubercles, tubercles fused forming a broad and almost V-shaped ridge. Eyes reduced, barely visible in dorsal view.Antennal scape rounded, longer than wide, dorsally punctate, with long straight brown setae; pedicel attached apically; antennal club dark brown, velutinous. Mouthparts with dense, brown setae. Labrum shape asymmetric with a transversal carina parallel to the posterior margin; surface of labrum punctate, punctures evenly spaced, each puncture bearing a long stout seta.

Pronotum ( Figs. 1–2 ). Strongly attenuated anteriorly, pronotal length almost half of elytral length, pronotal width only slightly narrower than elytron width. Sides of pronotum broad and flat, lateral margin smooth, tomentose with fringes of stout setae, anterior angle acute, posterior angles obtuse; base of pronotum obliquely truncate laterally behind posterior angles, base evenly rounded, marginate, margin setose, weakly notch medially (at scutellum). Pronotal surface with discrete, round punctures, uniformly spaced, rather close, space between punctures less than diameter of punctures, exception on apex where punctures are more widely spaced, surfaces between punctures dull with superficial fine microreticulation present between punctures. Median discal area of pronotum distinctly raised, broad, stretching over length of pronotum, somewhat flattened anteriorly and strongly declivous on sides; median pronotal ridges distinct, extending almost to pronotal base with deep depression between, partly obstructed in the middle by partial transverse ridge; with another distinct ridge present laterad of and almost parallel to the anterior half of the median discal ridges, with shallow depression between; laterad of median pronotal ridges in posterior half a single broadly-flattened tubercle, partly fused with discal ridges; median basal tubercles distinct, slightly laterally offset, not fused to discal ridges; distinct antero-lateral tubercle and lateral basal tubercle present on either side, basal one larger and elongate, apical one smaller and round; distinct lateral carina present below lateral tubercles; all tubercles and ridges setose.

Scutellum ( Fig. 1 ). Small, narrow, longer than wide.

Elytra ( Figs. 1–2 ). Elytral shape ovate; elytral length 2.1 of length of pronotum; surface matt, feebly shiny, finely alutaceous. Humeral angles rounded, calli absent, elytral sides flattened, lateral margins smooth to weakly undulate with regularly spaced tufts of setae along elytral length, margin laterally and ventrally tomentose; basal margin slightly concave with row of long setae. Sutural margin slightly raised, margin with tufts of setae; tufts roughly of similar size, separated, evenly distributed along margin. Elytral costae distinct, even-numbered costae more prominent than odd-numbered. Even-numbered costae with low oval to round tubercles (especially on intervals 2, 4 and 6); tubercles near base coalesced into an indistinct ridge, thereafter separated, distributed along elytral length, each with a large tuft of setae, tufts roughly of similar size. Odd-numbered costae marked by row of short setae; setae separate, irregularly spaced along elytral length. Intercostae marked by row of large round punctures; punctures deep, of similar size, regularly spaced over length of elytra.

Metathoracic wings. Completely reduce, only wing rudiments visible.

Legs ( Figs. 1–3 ). Protibiae straight, slender, with single prominent tooth on outer margin, ending with apical comb of short straight setae, apex narrow, semi flattened, squarely rounded; protibial spur stout, pointed forward, nearly as long as four basal tarsomeres combined; tarsal segments smooth; tarsomeres 1–4 subequal in length, tarsomere 5 as long as tarsomeres 2–4 combined; tarsomeres 1 and 2 without setae, tarsomere 3 ventrally with single fine seta, tarsomeres 4 and 5 ventrally each with single long stout seta; tarsomere 5 with two claws, simple, equal, small apicoventral process present on tarsomere below claws. Protibia dorsally with apical half marked by a series of irregular circular punctures, thereafter, modified into groove or series deep connected punctures; each puncture with a short erect seta; inner top edge of protibia marginate. Outer surface of protibia rugose with row of large round irregular punctures, some bearing single stout seta, outer margin distad of protibial tooth smooth, without indentations, margin proximad of tooth round, edge marked by row of straight stout setae. Inner protibial surface smooth, glabrous, proximad third with round punctures, sparsely setose; distad two thirds with rows of long setae. Protibia ventrally with double row of stout setae running closely parallel to outer edge, surface distad of lateral tooth rugose, surface proximad of lateral tooth semi-flattened, mostly smooth, glabrous. Profemur robust, widest basally, marginate on front face with row of straight forward pointing setae; ventral face with regularly spaced round punctures, each with single seta, surface in parts indumentose; dorsal surfaces on front face sparsely punctate, mostly smooth, glabrous, remainder of dorsal surface with long dense straight thin setae. Procoxa narrow, elongate, marginate on front face; surface rugose, punctuate, some punctures with stout seta, inner half indumetose. Protochanter indumentose, with small cluster of long erect setae. Mesotibial and metatibial surfaces smooth, feebly covered with fine indument; superomedial longitudinal carinae with row of stout setae; inner and outer carinae with row of long slender setae; outer margin on apex of meso- and metatibia with row of closely spaced stout backward pointing setae; meso- and metatibia with two apical spurs on inner margin; upper spur slightly longer than tarsomere 2, lower spur shorter than tarsomere 1. Mesotibia with three distinct separate teeth on lateral margin. Mesotarsi and metatarsi smooth, with long setae, tarsomeres 1–4 subequal in length, tarsomere 5 as long as tarsomers 3 and 4 combined; distal tarsomere with two claws simple, equal.

Ventral aspects ( Fig. 3 ). Proepisterna: Surface smooth, glabrous, with long thin setae, anterior margin distinctly raised, rounded, margin with row of long fine setae; prosternal apophysis broadly triangular; disc with short medial longitudinal ridge. Epipleura: Epipleura very broad basally, becoming slightly narrower distally, slightly concave along entire length, surface mostly smooth, feebly tomentose, weakly undulating, sparsely setose, setae fine; inner margin with thick tomentosity. Mesoventrum: Sunken below metaventrum; disc raised anteriorly, sunken posteriorly; mesoventrum apophysis prominent between mesocoxae, narrow, raised, extending almost the length of mesocoxa. Surfaces of mesoventrum rugose and coarsely punctate, punctures close, thickly indumentose, round to oval. Metaventrum: Metaventrum strongly convex, shortened, 2.8 times as wide as long, surface rugose and coarsely punctate, setose; lateral and anterior margin with tomentosity; plate sunken along mesocoxal margin forming narrow basinlike depression; metaventral disc rhomboidal, visibly depressed medially, with costate edges that converge outwards to distinct transverse carinae on either side of median depression, carinae setose, with covering of indument; plate strongly declivous behind without covering of indument. Abdominal ventrites: five visible ventrites (4–8); ventrite 4 with rugose surface, coarsely punctate, sparsely setose; ventrite 5 rugose in apical half, relatively smooth on distal half, medially with single transverse row of short stout setae; distal margins of ventrite 5 subparallel with apical margin of ventrite 6; ventrite 6 with band of coarse punctures along apical margin, remainder of surface smooth; distal third marked by transverse row of short stout setae arranged parallel to distal margin; distal margin concave; ventrite 7 only feebly punctate, surface mostly smooth, transverse row of short stout setae along distal margin, distal margin concave, curvature subparallel with distal margin of ventrite 6; ventrite 8 with distal margin convex, surface smooth, distal half with with short, evenly spaced setae.

Male. Unknown.

Differential diagnosis. Phoberus villeti Strümpher , new species, is quite different from all previously described flightless, and also alate, species of Phoberus and bear only superficial resemblance to the following species, P. aculeatus (Harold, 1872) ( Figs. 6–7 ) and P. horridus (Fabricius, 1775) ( Figs. 8–9 ). Phoberus villeti Strümpher , new species, can be easily distinguished at a glance from both by the presence of the very distinctive tufts of yellow setae present on the even-numbered costae and lateral margin of the elytra ( Figs. 1–3 ). In contrast, P. aculeatus and P. horridus have straight, and almost spine-like black setae on the even-numbered costae and lateral margin, giving them a prickly appearance ( Figs. 6, 8 ).

Comments. I am well aware of the undesirability of basing a description on a single female specimen, especially in Phoberus , where male genitalia are important for species recognition since shape and associated aedeagal characters, with few exceptions ( Strümpher & Scholtz 2017, 2019), are usually unique to each species. However, in this case, the description of the new species can be justified for the following reasons. First, the new species is sufficiently morphologically diagnosable and can hardly be confused with any of the other species in the genus. Second, due to the limited amount of sexual dimorphism in Phoberus descriptions and diagnoses of species largely applies equally to males and females. Lastly, flightless species of Phoberus are rare in collections, and in nature. They have restricted distributions and because of their elusive nature are difficult to collect—thus, it is not surprising that this new species has gone unnoticed, till now—and many more flightless species await discovery in South Africa. The species is described herein to bring it to the attention of coleopterists working in the region with the hope that additional material including males will be discovered in other localities.

Distribution. Known only from the type locality ( Fig. 5 ).

Etymology. The specific epithet honours Martin H. Villet, professor of Entomology at Rhodes University (Makhanda, South Africa), the author’s doctorate supervisor and mentor. It is formed in the genitive singular case.

Figures

FIGURES 1–5. Holotype of Phoberus villeti Strümpher, new species (ALBM). 1, habitus, dorsal view; 2, habitus, lateral view; 3, habitus, ventral view; 4, labels; 5, occurrence of Phoberus villeti Strümpher, new species, Eastern Cape Province, South Africa.

FIGURES 6–9. Phoberus aculeatus (Harold, 1872) (TMSA). 6, habitus, dorsal view; 7, labels. Phoberus horridus (Fabricius, 1775) (TMSA). 8, habitus, dorsal view; 9, labels.