Throx sulcatus Thunberg, 1787

Strümpher, Werner P., Huchet, Jean-Bernard & Costa-Silva, Vinícius Da, 2025, Phoberus sulcatus (Thunberg, 1787) sensu lato: in-depth morphological analysis of male genitalia reveals three cryptic species (Coleoptera: Scarabaeoidea: Trogidae), Zootaxa 5660 (3), pp. 301-329 : 307-312

Neotype designation for Throx sulcatus Thunberg, 1787

The catalogue of insect type specimens in the Thunberg collection at Uppsala University ( UUZM) ( Wallin & Wallin 2001) lists two “ type ” specimens (Nos 2140 and 2160) of Throx sulcatus . Upon examination of the corresponding material, it was discovered that the two specimens in the collection presently listed as types of Throx sulcatus are, in fact, specimens of Phoberus horridus ( Fabricius, 1775) ( Fig. 25 ). The latter is a large, easily recognisable, flightless species found in the southwestern part of the Western Cape province of South Africa ( Scholtz, 1980). Johan Christian Fabricius described it (originally in the genus Trox ) 12 years before Thunberg described Throx sulcatus . Thunberg described Trox silphoides (also as Throx ) on the same 1787 page. Harold (1872: 36) synonymized the latter nominal species with Phoberus horridus (as Trox horridus ), an action with which we agree; this is the species masquerading as Phoberus sulcatus in the Thunberg collection ( Fig. 25 ). In his more detailed redescription of Trox silphoides, Thunberg (1818: 450) mentioned that the body is dorsally convex (“supra convexus”) and the elytra are closed (“Elitra clause”) (here interpreted as being fused)—the main characteristics typically reflected in the external morphology of flightless trogid species, such as Phoberus horridus , are tightly fused elytra and a body shape convex in lateral view. Phoberus sulcatus , on the other hand, has fully functional wings, has a flatter general body profile, and its elytra separate easily; Thunberg (1818: 449) explicitly stated that this species is winged (“alato”).

It is notable that Throx sulcatus and Throx silphoides were both described on page 38 of Thunberg (1787), and are the only two nominal species of Phoberus (or Trox ) described in that work. We are certain that Thunberg would not have confused Trox sulcatus with Trox silphoides , and that the two specimens of Phoberus horridus standing as such ( Fig. 25 ) cannot be (the) syntypes of Trox sulcatus . Both Phoberus sulcatus and Phoberus horridus are morphologically well defined, readily recognisable as different species. We suspect that the type specimens of Trox sulcatus were mistakenly substituted with specimens of Phoberus horridus (i.e. Trox silphoides ) in the Thunberg collection. It is clear that the red curatorial type labels ( Fig. 25 ) currently associated with the two Phoberus horridus specimens were added more recently, as they were produced by digital printing.

Labels pinned in the drawers that contained the specimens, handwritten by Thunberg (handwriting compared in Horn et al. 1990: Teil II, plate 36, fig 17), are the only remaining evidence of the Throx sulcatus types having been in Thunberg’s collection ( Fig. 25 ). There are no other specimens of Trox sulcatus present in the Thunberg collection. Our efforts to locate the missing syntypes in other museums ( MNHB, MNHN, NHMB, NHMUK, NHMW, NHRS, NMPC, SDEI) were unsuccessful. We hence believe that the original type material of Throx sulcatus is lost.

An equivalent case of mistaken substitution was also noted for one of the two syntypes of Throx silphoides (Thunberg type No. 2142) in the Thunberg collection, which appears to have been substituted with a specimen of Phoberus caffer ( Harold, 1872) (WPS, personal observation).

The Thunberg collection in Uppsala contains inconsistencies due to mistaken substitutions that require further investigation. Such substitutions are particularly likely in this collection because none of the specimens have locality labels, determination labels or labels indicating their type status. Additionally, all the handwritten name labels are pinned inside the drawers or trays instead of being attached to the specimens. This practice was not uncommon in historical collections from that era. A similar situation was recently highlighted by Costa-Silva et al. (2024) in the Joseph Banks collection in NHMUK.

Even though the types of Trox sulcatus could not be studied/traced, Harold (1872), Haaf (1953) and Scholtz (1979, 1980) clearly defined the distinguishing characteristics of Phoberus sulcatus (then as Trox ), which can be readily identified from other similar species in the genus by the characteristic male genitalia ( Figs 4 , 18, 21 ).

Type specimens are important to maintain the nominal species’ stability and to avoid future misidentification. Considering that the supposed missing type specimens of Trox sulcatus from Thunberg’s collection correspond to the modern concept of Phoberus sulcatus (sensu Harold [1872], Haaf [1953] and Scholtz [1979,1980]), we understand that a designation of a neotype is necessary according to Article 75 of the ICZN (1999). Therefore, we propose the designation of a neotype here to establish the single name-bearing type specimen of Throx sulcatus . The neotype specimen fulfils the requirements of ICZN Article 75.3 ( ICZN 1999). We selected a well-preserved male from Zwartskraal farm in the Western Cape province, South Africa, from the collection of the TMSA ( Figs 1–5 ).

Additional material with precise localities examined (599 specimens). SOUTH AFRICA: Western Cape. 1♂ [Matjiesfontein], Table Farm , 33°10′S 20°31′E, found on carcass, 2.iii.1996, KI Krel ( CJBH). 2♂, 2♀ Beaufort West, De Hoop [farm], 32°08′S 22°44′E, 14–16.ix.1983, S Louw & A van Rensburg ( BMSA). 11♂, 13♀ Klaarstroom, Zwartskraal [farm], 33°10′S 22°32′E, riverine bush, pitfall traps: 8.xi.1978 - 16.i.1979, E-Y:1540, S Endrödy-Younga ( TMSA). 3♂, 28 spec. unsexed idem but 31.iii.1979 - 29.iv.1979, E-Y:1568 ( TMSA). 1♀ idem but 30.viii.1979, E-Y:1622, hand-collected, sand ( TMSA). 18♂, 116 spec. idem but 1.ii.1979 - 1.iii.1979, E-Y:1545, R Oosthuizen (1 SAMC; 133 TMSA). 12♂, 18 spec. unsexed idem but 2.iii.1979 - 30.iii.1979, E-Y:1552 ( TMSA). 2♂, 9 spec. unsexed idem but 30.iv.1979 - 10.vi.1979, E-Y:1571 ( TMSA). 1♂, 23 spec. unsexed idem but 11.vi.1979 - 22.vii.1979, E-Y:1574 ( TMSA). 4♂, 5♀ idem but rocky ridge, 23.vii.1979 - 4.ix.1979, E-Y:1637 ( TMSA). 2♂, 4♀ idem but 5.ix.1979 - 24.x.1979, E-Y:1639 ( TMSA). 4♂, 2♀ idem but 25.x.1979 - 8.xii.1979, E-Y:1672 ( TMSA). 4♂, 2♀ idem but 15.xii.1979 - 29.i.1980, E-Y:1693 ( TMSA). 12♂, 18 spec. unsexed idem but E-Y:1699 ( TMSA). 8 spec. unsexed idem but 18.iii.1980 - 5.v.1980, E-Y:1702 ( TMSA). 2♂, 5♀ idem but E-Y:1707 ( TMSA). 8 spec. unsexed idem but 26.vi.1980 - 5.viii.1980, E-Y:1710 ( TMSA). 1♀ idem but hand-collected at farm house, 26.vi.1980, E-Y:1715 ( TMSA). 23 spec. unsexed idem but 22.ix.1980 - 7.xi.1980, E-Y:1717 ( TMSA). 15 spec. unsexed idem but 8.xi.1980 - 19.xii.1980, E-Y:1737 ( TMSA). 1♂, 1♀ Zwartskraal farm, 33°10′S 22°32′E, x.1983, R Oosthuizen ( TMSA). 1♂ Groot Swartberg Nature Reserve, 33°20′S 22°01′E, i–ii.2006, Z van der Walt ( SANC). 4♂, 4♀ Oudtshoorn, Swartberg Pass, 33°21′S 22°03′E, pitfall traps: 13.iii.1979, W Breytenbach ( TMSA). 5♂, 4♀ Oudtshoorn, Koos Raubenheimer Dam, 2 km E, 33°24′S 22°19′E, bottom of dry, stony hill, pitfall traps: 22.x.1993 - 5.xi.1993, E-Y:2892, S Endrödy-Younga ( TMSA). Swartberg, Meiringspoort [ca. 33°25′S 22°33′E], ii.1932, KH Barnard ( SAMC). 1♂ Swartberg, Meiringspoort, Spitskop, [ca. 33°28′S 22°33′E], i.1935, Museum staff ( NHMB). 1♂ 2 spec. unsexed De Vlug, near Avontuur, Prince Alfred Pass, [ca. 33°45′S 23°08′E], 800 m, 16–19.xi.1981, fynbos, S & J Peck ( CMNC). 1♂ Wilderness, [ca. 33°59′40″S 22°34′30″E], xii.1955, V Fitzsimons ( TMSA). Northern Cape. 1♂ Victoria West, Melton Wold 158 [farm, mine], [31°27′S 22°45′E], 8–10.iii.1989, Entomology Dept. ( BMSA). 2♀ Richmond, Mynfontein [farm], [ca. 30°55′S 23°56′E], vi.1971, JS van Zyl ( TMSA). Eastern Cape. 2♀ Joubertina [33°49′S 23°51′E], 17.i.1982, AE Oelofsen ( BMSA). 1♂ Tsitsikamma National Park, 34°01′S 23°53′E, iii.1992, J Klimaszewski ( TMSA). 1♂ Aberdeen [32°29′S 24°04′E], i.1953, J Heyns ( SAMC). 1♂, 2♀ Graaff-Reinet, Paardekraal [farm], 32°12′S 24°09′E, 1,002 m, 3–7.ii.2003, dry xeric slope, DM Kroon ( TMSA). 1 spec. unsexed Baviaanskloofberg, 33°36′S 24°23′E, 868 m, pitfall traps: 15.xi.1982 - 15.xii.1982, WB238, W Breytenbach ( TMSA). 5♀ idem but 595 m, WB240 ( TMSA). 2♂, 2♀ idem but 183 m, WB241 ( TMSA). 1♂ Baviaanskloof Nature Reserve, 33°38′S 24°14′E, pitfall traps: 24.i.2021, WP Strümpher & GM Daniel ( TMSA). 1♀ Sneeuberge, Petersburg, 32°19′S 24°58′E, 6–14.xi.2012, M Krüger ( TMSA). 8 unsexed Middelburg, 31°30′S 25°01′E, pitfall traps: viii–x.1984, R Loubser ( SANC). 2♂, 8♀ idem but x–xii.1985, M de Jager ( SANC). 6♂, 6♀ idem but i–xii.1986 ( SANC). 4♂, 5♀ Nxuba, Mountain Zebra National Park, [ca. 32°15′S 25°27′E], 30.x.1986, A van Rensburg ( BMSA). 1 spec. unsexed Hogsback, 33°35′S, 26°55′E, collected on light trap, 16.x.2004, SI Wilsher ( CJBH). 4♂, 1♀ Gqeberha, [ca. 33°57′S 25°36′E], Dr Brauns, [no date] ( TMSA). 1♂ Gqeberha, Uitenhage Farms, Witteklip [33°54′S 25°15′E], JL Drege ( SANC). 1♂ Suurberg Pass, [ca. 33°17′S 25°43′E], 21.ii.1954, L. Vári ( TMSA). 1♀ Addo Elephant National Park, [ca. 33°28′S 25°47′E], 4.x.1996, KS Coles ( TMSA). 1 spec. unsexed Addo Elephant National Park, Kabouga House, 33°18′S 25°22′E, 217 m, x.2019 ( CJBH). 11♂, 4♀ Middleton, Sheldon [station], [33°01′S 25°50′E], 8.i.1950, Zumpt ( NHMB). 1♂, 1♀ Tarkastad, Kommandodrif Nature Reserve, 32°07′S 26°02′E, pitfall traps: 1–3.ii.2021, WP Strümpher & GM Daniel ( TMSA). 10♂, 10♀, 31 unsexed Sidbury, Amakhala Game Reserve, 33°31′16″S 26°08′27″E, pitfall traps baited with carnivore dung: iii–iv.2016, C Tocco ( AMGS). 1♀ Makhanda SW, Coldsprings [lodge], [33°20′S 26°29′E], 17.ii.1976, CF Jacot-Guillarmod ( AMGS). 1♂ Thomas Baines Nature Reserve, 33°24′S 26°30′E, 5.v.2005, JM Midgley, in exposed small intestine of dead White Rhinoceros Ceratotherium simum (Burchell) (TMSA) . 1 spec. unsexed Thomas Baines Nature Reserve, 33°25′S 26°30′ E, 25.iii.1996, C Mcilwaine ( CJBH). 2♂, 1♀ Makhanda, 33°20′S 26°32′E, 648 m, 5.ix.2009, WP Strümpher ( TMSA). 3♀ Makhanda, 1893 (1 SAMC, 2 SANC). 2♂, 2♀ Makhanda, May [18]97, Dr Chew (3 AMGS; 1 SAMC). 1♂ Makhanda, 6.viii.1967, M Bruton ( TMSA). 1 spec. unsexed Makhanda, 33°18′S 26°31′E, 10.v.2003, PD Collett ( CJBH). 1 spec. unsexed Makhanda, 33°19′S, 26°32′E, 12.v.2005, L De Wet ( CJBH). 1♀ Makhanda, 33°19′S 26°32′E, 20.iv.2005, JM Midgley, on dead Black-backed Jackal Lupulella mesomelas (Schreber) (TMSA) . 2♂, 2♀ Makhanda, Hilton, [33°15′S 26°21′E], 11.x.1983, AJ Weaving, from dried carcass of Vervet Monkey ( AMGS). 1♂, 1♀ idem but 16.x.1983 ( AMGS). 1♀ idem but 4.xii.1983 ( AMGS). 1♂ Makhanda, Rhodes University Campus, 33°18′S 26°32′E, 17.vi.1976, RHG Clarke ( TMSA). 5♂, 5♀, 20 unsexed Makhanda, Signal Hill, 33°20′S 26°33′E, 17.ix.2014, JM Midgley & MH Villet, on dead jackal, 1 week ( AMGS). 2♂, 2♀, 8 unsexed idem but 8.x.2014, on dead jackal, 4 weeks ( AMGS). 3♂, 3♀, 14 unsexed idem but 20.x.2014, on dead jackal, 6 weeks ( AMGS). 2♂ Katberg [32°29′S 26°41′E], 1–13.xi.1932 ( TMSA). 1♀ idem but 4 000 ft. [ca. 1,220 m], xii.1932 ( TMSA). 1♂ idem but 19–26.ii.1933 ( TMSA). 1♂ Komani, [31°54′S 26°52′E], i.1975, R.W. ( SAMC). 1♀ Port Alfred, Kap River Nature Reserve, 33°29′S 27°07′E, 4.ix.1994, on dried remains of Cape Bushbuck Tragelaphus sylvaticus (Sparrman) carcass, AJ Gardiner & EJ Bruce-Miller ( TMSA). 1♂ NW of Stutterheim, 32°32.3′S 27°23.5′E, 17–20.i.2016, P Bulirsch ( CJBH). 1♂ East London, 33°01′S 27°55′E, x.1974, GJ Petty ( SANC). 1♂ East London, Suffolk Farm, 5.xii.1998, PG Barratt ( CJBH). 1♂ Mthatha, 31°35′S 28°47′E, 4.xii.1989, N Duke ( SANC). KwaZulu-Natal. 1♀ Durban, [ca. 29°51′S 31°01′E], 1894, N Barker ( SAMC). 1♀ Umlaas Road, 29°44′S 30°30′E, 866 m, i.1983, P Atkinson ( SAMC). 1♂ idem but iv.1983 ( SAMC). 1♂, 1♀ idem but x.1984 ( SANC). 1♀ idem but xii.1984 ( SANC). 1♀ idem but x.1985 ( SAMC). 1 unsexed idem but vi.1997, PE Reavell ( SANC). 1♂, 1♀ Pietermaritzburg, [ca. 29°36′S 30°22′E], x.1983, PE Reavell ( SAMC). 1♂ Wartburg, [29°26′S 30°34′E], 11.ii.1953, IH Wiese ( SANC). 1♂, 1♀ oThongathi NNW, Warwick farm, 29°25′S 31°04′E, vi.2002, PE Reavell ( SANC). 1♀ Dalton, 29°20′S 30°37′E, vi.1997, PE Reavell ( SANC). 2♂, 3♀ idem but xii.1997 ( TMSA). 1♂ Estcourt, [29°01′S 29°52′E], Haviland ( SAMC). 1 unsexed Richards Bay, Lake Chubhu, 28°52′S 31°58′E, 19.iii.1980, light trap, RG Oberprieler ( SANC).

Additional material without precise locality examined (34 specimens). SOUTH AFRICA. 2♂, 3 unsexed Cap. b. Esp. [Cap de Bonne-Espérance, Cape of Good Hope] ( MNHN). 1♂ Cape Colony, 06.vi.1881 ( SAMC). 2 unsexed Cap [Cape Colony], Schmidt, Coll H Schapler ( SDEI: #303411, #303413). 1 unsexed Cap, Péringuey ( MNHN). 3♂, 2♀, 3 unsexed Cap ( MNHN). 1♂ Le Cap ( MNHN). 2♂ Cape ( MNHN). 1 unsexed Caffraria, Coll Kraatz ( SDEI: #303412). 1♂, 1 unsexed South Africa ( SAMC). 1 unsexed Afrique, Delalande ( MNHN). 1♂ Bf1-W ( SAMC). 1♂, 8 unsexed without data ( MNHN).

Trox instabilis, Haaf 1953 : Upon examining the type material of Trox instabilis , we recognised that, according to the current classification, the following nine paratypes are Phoberus sulcatus :

3♂♂, 1♀ ( NHRS: NHRS-JLKB000073767-000073770, aedeagi extracted, examined through detailed photographs): Rectangle, yellowing white, with printed text: “Cap. B. | Spei. [Cape of Good Hope] || Rectangle, white with handwriting: “ T. sulcatus ” || Rectangle white, printed text interspersed with handwriting: “ Trox ” | instabilis Haaf | det.Dr.E. Haaf 1953 ” || Rectangle, red cardstock with printed text: “ PARATYPE ” || Rectangle white, with handwriting (collector name label): “Åkerbg. [= Carl-Gustav Åkerberg (1827–1888) Swedish Consul in South Africa, donated his collection to Stockholm Museum in 1867]” || each with different curatorial label, white: “NHRS-JLKB | 000073767”; NHRS-JLKB | 000073768; NHRS-JLKB | 000073769; NHRS-JLKB | 000073770 || Curatorial label, light blue: “8656 | E92” || Rectangle, white cardstock with black margin: “ Phoberus sulcatus | ( Thunberg, 1787) | det. WP Strümpher 2023 ”.

1♀ ( TMSA): Rectangle, white with black bars, handwritten text: “Rietf. | 30.9.[19]04. ll” || Narrow rectangle, red: “ PARATYPE ” || Rectangle, white, printed text interspersed with handwriting: “ Trox ” | instabilis Haaf | det. Dr.E. Haaf 1953 ” || Rectangle, white cardstock with orange margin, printed text with handwriting: “ Paratypus 1953 | Trox | instabilis sp.n. | E. Haaf” || Rectangle, white cardstock with black margin: “ Phoberus sulcatus | ( Thunberg, 1787) | det. WP Strümpher 2023 ”.

1♂ ( MNHN):Rectangle, yellowing white with handwritten text:“Le Cap” || Narrow rectangle,red:“ PARATYPE ” || Rectangle, faded blue, printed text: “MUSEUM PARIS | 1930 | COLL SICARD ” || Rectangle, white cardstock with handwriting: “ Trox | luridus | v. capensis ” || Rectangle, white, printed text interspersed with handwriting: “ Trox ” | instabilis Haaf | det.Dr.E. Haaf 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus sulcatus | ( Thunberg, 1787) | det. WP Strümpher 2023 ” .

1♀ ( SDEI, examined through detailed photographs): Rectangle, yellowing white, handwriting: “Caffraria” || Rectangle, yellowing white, with printed text: “ Coll . Kraatz” || Rectangle, white, handwriting: “Felsche det” || Rectangle, white with printed text: “Dtsch.Entomol. | Institut Berlin ” || Rectangle, yellowing white, printed red text: “ PARATYPUS ” || Rectangle white, printed text interspersed with handwriting: “ Trox ” | instabilis Haaf | det. Dr.E. Haaf 1953 ” || Rectangle white, curatorial label with printed text: “ SDEI Coleoptera | #303337” || Rectangle, white cardstock with black margin: “ Phoberus sulcatus | ( Thunberg, 1787) | det. WP Strümpher 2023 ”.

1♀ ( MNHN): Rectangle, faded white cardstock, handwritten text: “Cap” || Narrow rectangle, red: “ PARATYPE ” || Rectangle, faded grey cardstock, printed text: “MUSEUM PARIS | Coll . L. BEDEL 1922” || Rectangle, white, printed text interspersed with handwriting: “ Trox | instabilis Haaf | det.Dr.E. HAAF 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus sulcatus | ( Thunberg, 1787) | det. WP Strümpher 2023 ”.

1♀ ( FMNH, examined through detailed photographs):Rectangle, faded white cardstock, with printed text: “ Cape | Colony” || white square: “ ♀ ” || Rectangle, white, printed red text interspersed with handwriting: “ PARATYPUS | Trox | instabilis sp.n. | det.Dr.E. HAAF 1953 ” || Rectangle, faded white cardstock, with printed text with handwriting: “Chicago N. H. Mus[eum]. | ex Museum G. Frey | by exchange 1963” || Rectangle white, printed text interspersed with handwriting: “ TROX | sulcatus Thunb. | det. C.H. SCHOLTZ 1979 ” || Rectangle, white cardstock with black margin: “ Phoberus sulcatus | ( Thunberg, 1787) | det. WP Strümpher 2023 ”.

Redescription. Size: Length: 9.3–13.1 mm. Width: 5.5–7.2 mm.

Body shape. Convex, elongate oval, elytral margins widest behind the middle, elytral profile convex, broadly rounded, declivous posteriorly, attaining maximum height in the middle.

Colour ( Figs 1–3 ): Matt black. Body setae mostly yellow, sometimes brownish yellow.

Head ( Figs 1–2 ): Surface coarsely sculpted with discrete round punctures, punctures irregularly spaced and close, interspaces vary between equal to or less than puncture diameters. Clypeus obtusely triangular, disc slightly elevated, feebly convex, apically deflexed and rounded; anterior clypeal margin entire, bare; clypeogenal and frontoclypeal sutures distinctly raised; frontoclypeal suture complete, with a low clypeogenal tubercle present on either side, tubercles punctate. Frons raised, with paired, arched, setose frontoclypeal carinae delimiting two semicircular depressions, separated by a setose median carina, carinae on frons marked by row of erect, stout seta. Genal angles obtuse; genae wide, shape triangular, surface depressed, coarsely sculpted; genal margin with distinct row of long erect setae. Eyes large and bulbous, scarcely visible in dorsal view. Antennal scape rounded, longer than wide, surface punctate, with long, straight, light brownish yellow setae; pedicel attached apically; antennal club brown, velutinous; mouthparts with dense, yellow to rust-brown setae around. Labrum shape asymmetric; surface of labrum coarsely punctate, each puncture bearing a long stout seta.

Pronotum ( Figs 1–2 ): Pronotal width only slightly narrower than elytra, widest at base, pronotal length one third of elytral length. Lateral margins broad, explanate and curved, attenuate anteriad, somewhat irregular to coarsely dentate, with fringes of broad spatulate setae; anterior angles acute, posterior angles almost right angled. Base of pronotum marginate (bordered) and projecting backward with weakly produced posteromedian lobe; base obliquely truncate laterally behind posterior angles, entire basal margin with dense fringe of spatulate setae; basal edge with distinct posteromedian notch (opposite scutellum), edge sinuated on either side of notch. Pronotal surface coarsely sculpted with discrete round punctures, irregularly spaced, punctures close, interspaces vary between equal to or less than puncture diameters, surface between punctures dull with superficial fine microreticulation present between punctures. Median discal area of pronotum distinctly raised, broad anteriorly, narrowing towards base forming crudely shaped triangular disc stretching almost over length of pronotum, somewhat flattened anteriorly and strongly declivous on sides and behind; median pronotal ridges distinct, broad anteriorly, with slight depression in the middle, parallel to median groove, ridges interrupted at approximately two-thirds of the length from the anterior margin by a depression; median groove entire stretching almost over length of pronotum, on anterior third widened into slight rounded depression, then partially constricted at approximately two-thirds of the length from the front, thereafter widening into slight round depression (on declivity); median basal tubercles distinct, slightly laterally offset (in line with second elytral costa), not fused to discal ridges; two lateral tubercle (one medially and one basally) present on either side, these tubercle partially fused forming a crude ridge; distinct lateral carina present below lateral tubercles; all tubercles and ridges setose.

Scutellum ( Fig 1 ): Longer than wide, oval; surface smooth, apicolaterally rounded and mediobasally depressed; depression weakly sculpted to punctate; margin smooth, tomentose.

Elytra ( Figs 1–2 ): Elongate, length 2.7–2.8 pronotum length, lateral margins subparallel, margin widest at ca. 0.6 length; sides narrow and not explanate, outer lateral margin distinctly dentate or irregular over basal third with setae usually arranged in tufts (if not worn down); setae more regularly distributed over the rest. Humeral calli prominent bearing small tubercles with short, stout setae; humeral angles obtuse, blunt. Sutural margin raised, surface smooth, with low oval to elongate 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, even numbered costae more prominent than odd-numbered. Even-numbered costae with large, raised oval to elongate tubercles, these tubercles smooth, dull shiny, each with a posterior setal tuft; weak apical callosity present on fourth costal interval at top of elytral declivity; costae 2 and 4 with 9–11 tubercles for 0.75 elytral length (up to apical callosity), these tubercles close and fairly evenly spaced along elytral length, distance between tubercles roughly equal to or less than length of tubercles; tubercles on costae 6 and 8 more widely spaced, distance between tubercles equal to or greater than length of tubercles. Odd-numbered costae (1, 3, 5, 7, 9) marked by small round to oval, dull 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 surfaces undulated, marked with distinct round to ovoid punctures (depressions), punctures separated by transverse ridges, punctures evenly spaced along elytral length, distance between ovoid puncture roughly equal to the diameter of puncture; punctures on intercostae roughly equal in size for 0.75 elytral length (up to apical callosity), thereafter slightly decreasing in size; punctures on intercosta 10 (on elytral margin) larger, oval in shape; dorsally margins of intercostae 1–4 marked by weak narrow longitudinal ridges (carinae); intercostal carinae laterally vestigial, barely discernible or lacking.

Metathoracic wings: Complete.

Ventral aspects: Legs ( Figs 1–3 ): Protibia dorsally keeled, ending with small upward projecting apical process and row of short stout transverse setae; protibial apex divided into two teeth, distinct in males, females with teeth partly fused; protibial spur stout, pointed forward, flattened laterally, apex slightly curved; as long as, or longer than, third tarsomere; tarsal segments smooth, tarsomeres 1–4 subequal in length, fifth tarsomere longest, with two simple and equal claws; tarsomeres 2–4 ventrally each with two long seta; outer tibial margin with two distinct median teeth and 4–5 smaller basal teeth; in lateral aspect the dorsal longitudinal ridge (keel) on protibia dentate, with row of long, straight setae; dorsally outer tibial surface rugose and punctate, each puncture with short straight seta; both the inner and ventral tibial surfaces smooth and shiny, longitudinally with two crude, shallow, almost continuous parallel grooves (formed from rows of coalesced punctures), grooves on inner tibial surface with numerous long thin setae, setae on ventral surface shorter and less numerous. Procoxa narrow, flattened in front, surface rugose and punctate, basal section indumentose. Profemur large, widest medially, marginate on front face with row of straight forward pointing setae; ventral face with regularly spaced round punctures, each with single short seta; surface dull with superficial reticulation; dorsal surfaces smooth. Meso- and metafemora slender; fore margins rounded, hind margins semi-flattened, marginate with row of stout setae; ventral face rugose, with regularly spaced round punctures, each with single stout seta; dorsal surfaces smooth. Mesotibia and metatibia slender, outer margins dentate and with short, stout yellow setae; inner surface smooth, glabrous, upper and lower margins with long straight setae; outer margin on apex of both meso- and metatibia with row of closely spaced stout backward pointing setae; inner margin of meso- and metatibia with two apical spurs, upper spur slightly longer than lower spur, spurs as long as, or slightly longer than second tarsomere; tarsal segments of both meso- and metatibia smooth, segments 1–4 subequal in length, ventrally each with (four to five) long straight backward pointing setae, fifth tarsomere as long as tarsomeres 2–4 combined, with two equal and simple claws.

Proepisterna ( Fig. 3 ): Surface glabrous, with fine scattered setae, basal margin distinctly raised, marginate; margin punctate with long thin setae; disc with short medial longitudinal ridge. Epipleura : Broad basally narrowing apically; weakly concave along entire length; surface mostly smooth, mid longitudinal row of short setae present along entire length; inner margin distinctly marginate, margin tomentose with scattered short setae. Mesosternum: Sunken below metaventrite, with distinct basolateral depression on either side (visible on clean specimens); surface rugose and coarsely punctate on basal halve, these punctures close, irregular to round or oval, each puncture with single seta; surface on distal halve smooth, sparsely punctate; mesosternum apophysis prominent between mesocoxae, extending almost the length of mesocoxa, narrow (thinly triangular), pointed, with medial longitudinal ridge, surface tomentose. Mesepisternum: surface weakly undulating, rugulose, sparsely setose, distal margin raised, thick. Metepisternum: surface rugulose, with rows of scattered setae along inner margin, inner margin marginate and tomentose. Metasternum: Convex, about 1.7 times as wide as long; surface rugose and coarsely punctate, with evenly scattered short setae; lateral and anterior margin marginate, raised, tomentose; distal margin smooth, plate sunken along mesocoxal margin forming narrow basin like depression; metasternum apophysis prominent between mesocoxae, raised, keeled-like; metaventral disc rhomboidal, visibly depressed medially (discrimen), outer margin with small medial pointed triangular projection; plate strongly declivous behind, transverse edge/margin strongly sinuate on either side of median depression, declivity rugulose and without setae. Abdominal ventrites: Five visible sternites (IV–VIII); sternites IV–VII surface coarsely sculpted with arch-shaped grooves, grooves forming a semicircular pattern, surface between grooves dull shiny, remainder of surface smooth, glabrous, with row of fine punctures running parallel to the distal margin, punctures irregularly spaced, each with short seta, lateral margins setose; distal margin of sternite V straight, subparallel with distal margin of sternite IV, distal margins of sternite VI and VII slightly concave; sternite VIII with distal margin convex, setose, surface finely sculpted, feebly punctate.

Male genitalia ( Figs 4 , 18, 21 ): Bilaterally symmetrical, slender, strongly sclerotised. Phallobase, elongate, subovate in dorsal view, arched in lateral view; slightly shorter than parameres. Parameres long, slender, extending beyond phallus, in dorsal aspect broadly curved down and inward ( Figs 18a, 21o ); parameres in lateral aspect slender basally, very broadly expanded medially ( Fig. 21n ), apically slender, narrowed, apices strongly decurved (never straight or projecting forward) and pointed ( Fig. 21 ). Phallus divided into two symmetrical concave lobes (curved inwards) ( Figs 4 , 18b ), lobes broad basally, curved sections elevated, inner margins curved (never straight) (Fig, 18c), apices rounded, flattened, pointed inwards ( Fig. 18 ); two bladelike projections and hooks visible between parameres and phallus.

Differential diagnosis. The males of Phoberus sulcatus can be distinguished from the males of P. instabilis ( Haaf, 1953) and P. erwinhaafi Strümpher , sp. nov. by the following combination of characteristics: the parameres in lateral profile are broad and distinctly enlarged in the middle ( Fig. 21n ); the apices are narrow and always curved downward ( Fig. 21m ); and the dorsal margin at the apex is always strongly curved or rounded ( Fig. 21o ).

The three species treated here closely resemble Phoberus cyrtus ( Haaf, 1953) , Phoberus fumarius ( Haaf, 1953) , and Phoberus caffer ( Harold, 1872) , and may be readily confused with them. For detailed morphological descriptions and diagnostic characters that distinguish these taxa, consult Strümpher & Scholtz (2019) and Strümpher & Stals (2021).

Geographic distribution. Phoberus sulcatus is presently known from the Eastern Cape, KwaZulu-Natal, the southeastern part of the Northern Cape and the eastern part of the Western Cape provinces of South Africa ( Fig. 24 ). The distribution of Phoberus sulcatus seems to fall outside of the winter rainfall region of South Africa (roughly east of 21°E). Previously, Scholtz (1980), in his monographic revision, reported Phoberus sulcatus (s.l.) occurring as far west as Cape Town, as well as from a few localities from the northwestern part of erstwhile Cape Province [= present-day Northern Cape province] ( Scholtz, 1980: 85, Fig. 170). However, during this study, we re-examined all the specimens from Scholtz (1980) that was accessible to us, as well as all other “ sulcatus -like” specimens collected from west of 21°E that have accumulated in South African museums post Scholtz (1980). We found that these specimens were either misidentified or belong to: Phoberus caffer ( Harold, 1872) (see Strümpher & Scholtz 2019), Phoberus fumarius ( Haaf, 1953) (see Strümpher & Stals 2021), Phoberus luridus ( Fabricius, 1782) (see Scholtz 1980) or Phoberus planicollis ( Haaf, 1953) (see Scholtz 1980). Even extensive collecting in winter rainfall areas of the Northern and Western Cape provinces over the past two decades yielded no further records of Phoberus sulcatus (WPS personal observation).

Natural history. Collection data show that adults were collected in pitfall traps baited with human dung, carrion (meat), carnivore dung, or a mixture of fresh pig dung and chicken livers. Individuals have also been collected on dried remains of various small and large mammals, such as jackals, bushbucks, cats, cattle, dogs, horses, sheep, vervet monkeys, and rhinos. Based on the collection records, Phoberus sulcatus appears to be active all year round. Immature stages are unknown.

Figures

FIGURE 24. Known distribution of Phoberus sulcatus (Thunberg, 1787) (= green circles); Phoberus instabilis (Haaf, 1953), revalidated and new combination (= blue circles); Phoberus erwinhaafi Strümpher, sp. nov. (= red circles).

FIGURE 25. The two specimens of Phoberus horridus (Fabricius, 1775) in the Thunberg collection (in the Zoological Museum, Uppsala University, Sweden) were mistakenly substituted as the type specimen of Throx sulcatus. Photos by Hans Mejlon.

FIGURES 1–5. Neotype of Phoberus sulcatus (Thunberg, 1787), herein designated (TMSA). 1, habitus, dorsal view; 2, habitus, lateral view; 3, habitus, ventral view; 4, aedeagus, dorsal and lateral views; 5, neotype labels.

FIGURES 18–23. Male genitalia. Phallus and parameres in dorsal aspect (18–20). Parameres in lateral aspect (21–23). Phoberus sulcatus (Thunberg, 1787), 18, 21. Phoberus instabilis (Haaf, 1953), revalidated and new combination, 19, 22. Phoberus erwinhaafi Strümpher, sp. nov., holotype, 20, 23. a–t, for an explanation, refer to Table 1. Dashed arrows indicate the projection of parameres in dorsal view.