Phoberus cyrtus ( Haaf, 1953 )

Strümpher, Werner P. & Stals, Riaan, 2021, Proper cleaning of keratin beetles reveals a cryptic species: Phoberus fumarius (Haaf, 1953) from southern Africa is reinstated as valid (Coleoptera: Trogidae), Zootaxa 4942 (4), pp. 543-557 : 545-549

Phoberus cyrtus ( Haaf, 1953)

( Figs 1–7 , 15 , 21 )

Trox cyrtus Haaf, 1953: 333 (original description).

Trox (Trox) cyrtus: Scholtz 1980a: 66 , 68, 87, 97 (redescription, illustrations, distribution); Scholtz 1982: 3 (catalogue).

Trox (Phoberus) cyrtus: Zidek 2013: 9 (checklist).

Phoberus cyrtus: Strümpher et al. 2016b: 78 (new combination); Zídek 2017: 99 (checklist).

Type locality. Vallée du Haute Orange [Valley of high Orange River] (border of Mohale’s Hoek and Quthing Districts , Lesotho)

Type material examined. All type specimens were examined through detailed photographs. HOLOTYPE Ƌ ( MNHN, aedeagus extracted) ( Figs 1–3 ): Rectangle , faded blue cardstock: “MUSEUM PARIS | Basoutoland, Lessouto [ Lesotho] | Vallée du Ht Orange [Valley of high Orange River, 30°17′S 27°46′E], 1500 m. | (legit R. Ellenberger) | E. HAUG 1906” || Rectangle, red cardstock: “ HOLOTYPE ” || Rectangle, minimally foxing white: “ Trox | cyrtus Haaf | det. Dr.E. Haaf 1953 ” || Rectangular curatorial label, white: “ MNHN | EC10025 ” . PARATYPES 2ƋƋ ( MNHN): Blue label identical || Rectangle, red cardstock: “ PARATYPE ” || Foxy white label identical || White curatorial labels: “ MNHN | EC10027 ” and “ MNHN | EC10029 ” . PARATYPES 3♀♀ ( MNHN): Labels identical to those of ♁ paratypes, but each specimen with an additional foxy white square: “ ♀ ” || “ MNHN | EC10028 ”; “ MNHN | EC10026 ” with red label: “ ALLOTYPE ”; “ MNHN | 10030” with different determination label, white rectangle: “ PARATYPE | Trox | cyrtus Haaf, 1953 ” . PARATYPE 1Ƌ ( MNHB): Blue label identical || Rectangle, white, preprinted red text interspersed with black handwriting: “ PARATYPUS | Trox | cyrtus sp.n. | det. Dr.E. Haaf 1953 ” .

Haaf (1953) described this species from six males and four females, all with the same label data. We studied four males and three females of the type series, including the holotype. Haaf (1953) indicated that all ten type specimens would be lodged in the MNHN, but we located one male in the MNHB.

Additional material examined. SOUTH AFRICA. Eastern Cape Province. 1♁ Aliwal North , [30°42′S 26°42′E], 15–25.ii.1971, Snyman & Jones ( TMSA) . Free State Province. 13♁ Nova 667 [farm], near Ladybrand, SE 2927 Ab [29°07′S 27°22′E], 19–22.i.1976, GW Ferreira, S van Ee ( BMSA: BMSA (C)-21032–21044) ( Figs 4–7 ) . 3♁, 3♀ idem but 01–12.ii.1977, GW & MC Ferreira, A Strydom ( BMSA: BMSA (C)-21045–21046; BMSA (C)- 21975; BMSA (C)-21978; BMSA (C)-22031; BMSA (C)-22293) . 4♁, 4♀ Kerkenberg, near Harrismith, 2829 Ac /d [28°30′14″S 29°06′30″E], 08–18.xi.1976, Museum staff ( BMSA: BMSA (C)-21020–21027) . KwaZulu-Natal Province. 1♁ [uKhahlamba-Drakensberg Park World Heritage Site], Mdedelelo Forestry Area , 29°07′S 29°26′E, 13–14.xi.1981, SJ van Tonder, C Kok ( SANC) . 1♀ [uKhahlamba-Drakensberg Park World Heritage Site], Giant’s Castle Game Reserve , at Bannerman Hut, 29°15′S 29°26′E, 2,300 m, 24.iv.1994, J duG Harrison, R Stals ( TMSA) .

Mpumalanga Province. 1♁ Kruger National Park, Skukuza Rest Camp , 24°59′S 31°36′E, 28.i.1994, E-Y:2952, UV light trap, S Endrödy-Younga ( TMSA) . 1♁ Winkelhaak [mine], Ermelo district , [26°30′S 29°07′E], x.1970, L Schulze ( TMSA) . North West Province. 2♁, 7 unsexed: Rustenburg , [25°39′S 27°14′E], 28.x.1956 ( NHMB, through photographs). 7 unsexed: idem but 13.viii.1961 ( NHMB, through photographs). BOTSWANA . South-East District. 1♁ Otse , [25°02′S 25°44′20″E], 02.ix.1963, JA Nagle ( TMSA) .

Redescription. Size: Length: 9–13 mm. Width across humeri: 5–8 mm.

Colour ( Figs 1 , 4–5 ): Matt black, with dull reflection. Body setae yellow unless stated otherwise below.

Head ( Figs 4–5 ): Surface sculpted with discrete punctures, surfaces between punctures with dull reflection. Clypeus triangular, straight, apically deflexed and rounded; anterior clypeal margin entire, bare; clypeogenal and frontoclypeal sutures distinctly raised; frontoclypeal suture complete, with a low clypeogenal tubercle on either side, tubercles punctate. Frons raised, with paired, arched, setose frontoclypeal carinae delimiting two semicircular depressions, separated by a distinct, setose median carina. Genal angles obtuse, wide, recurved; genal margin with straight setae. Eyes large and bulbous, barely visible in dorsal view. Antennal scape rounded, longer than wide, punctate, with long light brown setae; pedicel attached apically; antennal club dark brown, velutinous. Setae around mouthparts dense, yellow to rust-brown.

Pronotum ( Figs 4–5 , 15 ): Slightly narrower than elytra. Surface with discrete, round punctures, surfaces between punctures dull to shiny. Lateral margins broad and flat, somewhat explanate, entire to irregularly, coarsely dentate, strongly attenuate anteriad, with fringes of long, straight setae. Apex with row of long, recurved, evenly spaced setae. Base with dense fringe of straight setae. Median discal area only slightly raised, broad, narrowing towards base to form a distinct triangular disc; dorsal outline evenly arched in anterior view; median discal depression shallow; median basal tubercles distinct; lateral basal tubercles fused to those in front of them to form a low, broad carina; all tubercles and ridges with setal tufts.

Scutellum ( Figs 4–5 ): Longer than wide; surface smooth; apicolaterally rounded, lateral margins straight; mediobasally depressed, depression weakly sculpted to punctate.

Elytra ( Figs 1 , 4–5 ): Elongate, length 2.7–2.8 pronotum length, lateral margins subparallel, sides narrow, lateral margin finely dentate and bearing long setae; widest at c. 0.6 length; profile slightly convex, attaining maximum height approximately in the middle, strongly declivous posteriorly. Humeral calli prominent, with short setae. Sutural margin raised, surface smooth, with low (sometimes flat) round to oval tubercles, widely separated and irregularly distributed along margin, roughly of similar size for 0.75 elytral length, thereafter decreasing in size until barely discernible; these tubercles smooth, dull shiny, each with a posterior setal tuft. Elytral costae distinct, evennumbered costae more prominent than odd-numbered. Even-numbered costae with raised oval tubercles widely and fairly evenly spaced along elytral length; these tubercles smooth, shiny, each with a posterior setal tuft. Apical callosity present on fourth costal interval at top of elytral declivity. Elytral costae 2 and 4 with 5–8 tubercles for 0.75 elytral length (up to apical callosity); odd-numbered costae marked by small round to oval, shiny tubercles, each with one or two short setae, these tubercles regularly spaced, roughly of equal size for 0.75 elytral length, thereafter decreasing in size until barely discernible. Dorsally costae 1–4 separated from intercostae as slightly elevated bands; laterally costae 5–9 barely discernible as bands. Intercostae with very shallow, undulating depressions separated by transverse ridges; dorsally, margins of intercostae 1–4 marked by weak narrow longitudinal ridges; intercostal carinae laterally vestigial, barely discernible or lacking.

Legs ( Figs 4–5 ): Surfaces rugose and coarsely punctate. Protibia dorsally keeled, with small apical process and row of short, stout transverse setae; outer margin with 2 distinct median teeth and 3–5 smaller basal teeth; inner margin with long, dense setae; protibial apex divided into two spines, distinct in males, females with spines partly fused; protibial spur as long as, or longer than, third tarsomere, flattened laterally, apex pointed and recurved. Mesotibia and metatibia with outer margins dentate and with long, dense yellow setae; with 2 apical spurs on inner margin, spurs as long as, or slightly longer than, second tarsomere. Tarsomeres ventrally with sparse setae. Tarsal claws simple, equal.

Metathoracic wings: Complete.

Male genitalia ( Figs 2 , 6 ): Symmetrical, slender; phallobase arched, slightly longer than parameres. Parameres long, extending beyond median lobe, apices pointed, long and decurved. Median lobe divided into two symmetrical parts, these narrow, subparallel, in dorsal view concave upward; apices acutely rounded; two bladelike projections and hooks visible between parameres and median lobe.

Diagnosis. Phoberus cyrtus and Phoberus fumarius are very similar, but the former can be distinguished from the latter in having a less coarsely punctate pronotum ( Figs 15–16 ). Additionally, the arrangement of the tubercles on elytral costae 2 and 4 differs between the species: Phoberus cyrtus has these tubercles widely separated, with 5–8 tubercles between the elytral base and the apical callosity, whereas these tubercles in Phoberus fumarius are close together, with 8–12 tubercles between the elytral base and the apical callosity. The male genitalia of the two species are distinctive with the most important differences found on the median lobes. Phoberus cyrtus have the lobes narrow and their apices sharper or angular, whereas in Phoberus fumarius the lobes are broad and their apices more rounded (as described in the text and as shown in Figs 2 and 6 versus Figs 9 and 13 ). Available information strongly suggests that the two species are allopatric and existent only in different, non-overlapping biomes, Phoberus cyrtus in the summer rainfall area of southern Africa and Phoberus fumarius in the winter rainfall area (see text and Fig. 21 ).

Phoberus sulcatus (Thunberg, 1787) ( Figs 17–20 ) is widespread and common throughout South Africa ( Scholtz 1980a). Both Phoberus cyrtus and Phoberus fumarius have an external appearance similar to that species, and the three may be confused. In collections they have certainly been confused. Of the two species treated in this work, Phoberus fumarius is more likely to be confused in this way. Phoberus sulcatus differs from both the other species in bearing a distinct median pronotal depression ( Fig 19 ) and having the pronotal and elytral carinae and tubercles more pronounced and higher ( Figs 17, 19 ). The male genitalia of Phoberus sulcatus are indubitably different with the median lobe of this species divided into two broadly curved lobes ( Fig 18 ). We found that Phoberus sulcatus can readily be distinguished from these other two species by the larger shadows cast under oblique lighting by its more prominent paramedian pronotal carinae; specimens should not be too soiled for this comparison to succeed.

Geographic distribution. Phoberus cyrtus is known from South Africa, Lesotho and Botswana ( Fig. 21 ). In South Africa the species has been recorded from the Eastern Cape, KwaZulu-Natal, Mpumalanga and North West Provinces.

Broad habitat associations. As far as it is known, Phoberus cyrtus is restricted to the summer rainfall region of southern Africa, in contrast to its putative sister species Phoberus fumarius , which is confined to the winter rainfall region. Phoberus cyrtus is known from two biomes. In the south of its known distribution, the species lives in the Grassland Biome, where it is present in the Mesic Highveld Grassland–, Drakensberg Grassland– and Dry Highveld Grassland Bioregions (biomes and bioregions following Mucina & Rutherford 2006; Dayaram et al. 2019). Towards the north and west of its range, the species occurs in the Savanna Biome (Central Bushveld– and Lowveld Bioregions). Whereas the grassland habitats are cool and mesic, the savanna habitats are warm to hot and experience extended dry periods. This discordant distribution among two sets of habitats with significantly different bioregional climate regimes may indicate a eurytopic species.

Figures

FIGURE 21. Known distribution of Phoberus cyrtus (Haaf, 1953) and Phoberus fumarius (Haaf, 1953).

FIGURES 1–3. Holotype of Trox cyrtus Haaf, 1953 (MNHN). 1, habitus, dorsal view; 2, aedeagus, dorsal view; 3, holotype labels. Photographs by Antoine Mantilleri, copyright MNHN.

FIGURES 4–7. Phoberus cyrtus (Haaf, 1953), specimen with obscuring layer of dirt removed (BMSA). 4, habitus, dorsal view; 5, habitus, lateral view; 6, aedeagus, dorsal and lateral views; 7, labels.

FIGURES 15–16. Pronotal disc, dorsal view. 15, Phoberus cyrtus (Haaf, 1953); 16, Phoberus fumarius (Haaf, 1953).

FIGURES 8–10. Holotype of Trox fumarius Haaf, 1953 (NHMB): 8, habitus, dorsal view; 9, aedeagus, dorsal view; 10, holotype labels. Photographs by Christoph Germann, copyright NHMB.

FIGURES 11–14. Phoberus fumarius (Haaf, 1953), revalidated and new combination, specimen with obscuring layer of dirt removed (TMSA). 11, habitus, dorsal view; 12, habitus, lateral view; 13, aedeagus, dorsal and lateral views; 14, locality label.

FIGURES 17–20. Phoberus sulcatus (Thunberg, 1787), cleaned specimen (BMSA). 17, habitus, dorsal view; 18, aedeagus, dorsal view; 19, pronotal disc, with red arrow indicating distinct median pronotal depression; 20, specimen labels.