Phoberus instabilis ( Haaf, 1953 )

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 : 313-318

Phoberus instabilis ( Haaf, 1953) , revalidated and new combination

( Figs 6–8 , 9–12 , 19, 22 , 24 )

Trox instabilis Haaf, 1953: 331 (original description); Haaf 1959: 478 (checklist, localities); Scholtz 1978: 83–84 (distribution, as Trox sulcatus ); Scholtz 1979: 193 (new junior synonym of Trox sulcatus ); Scholtz 1980: 89 (as a synonym of Trox (Trox) sulcatus ); Scholtz 1982: 7 (catalogue, as a synonym of Trox (Trox) sulcatus ); Louw 1987: 421, 435 (faunistics, as Trox sulcatus ); Zidek 2013: 11, 17 (checklist, as synonym of Trox (Phoberus) sulcatus ); Zídek 2017: 102, 109 (checklist, as synonym of Phoberus sulcatus ); Muvengwi et al. 2018: 8488 (faunistics, as Trox sulcatus ).

Type locality. Zimbabwe, Harare Metropolitan Province , Harare; as “ Salisbury, Southern Rhodesia”. Harare is the capital of Zimbabwe and lies at an average elevation of 1,461 m above mean sea level.

Type material examined (11 type specimens). Holotype ♂ ( NHMB, aedeagus extracted) ( Figs 6–8 ): Rectangle, white: “Salisbury [= Harare; 17°49′S 31°03′E] | S.Rhodesia [ Zimbabwe] | Zumpt XI [19]51 || Rectangle, white: “Museum Frey | Tutzing” || Rectangle, white with red bars at top and bottom, printed red text interspersed with black handwriting: “HOLOTYPUS | Trox | instabilis sp.n. | det.Dr.E. HAAF 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”. Paratype 1♂ ( NHMB, aedeagus extracted): Rectangle, yellowing white: “Transvaal | 1883” || Narrow rectangle, yellowing white with black bars at top: “EX MUSEO | N. VAN DE POLL” || Rectangle, white, printed text interspersed with handwriting: “PARATYPUS | Trox | instabilis sp.n. | det.Dr.E. HAAF 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”. Paratypes 1♂, 1♀ ( NHMB): Rectangle, yellowing white with printed text: “ Johannesburg [ca. 26°12′S 28°02′E] | Transv.S.Afr. | Zumpt 14 22.XII.[19]52” || Rectangle, white, printed text interspersed with handwriting: “PARATYPUS | Trox | instabilis sp.n. | det.Dr.E. HAAF 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”. Paratype female with an additional label, white: “♀”. Paratype 1♂ ( TMSA, aedeagus extracted): Rectangle, white with green bars on margin, printed text: “Lydenburg [now Mashishing: South Africa, Mpumalanga, ca. 25°04′S 30°26′E] | Distr. 1896 | P. A. Krantz ” || 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 | E. Haaf sp.n. ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”. Paratypes 3♂♂ ( NHMB, aedeagi extracted): Rectangle, faded blue cardstock, printed text: “MUSEUM PARIS | BASOUTOLAND [ Lesotho] | MASERU [Maseru District, 29°18′S 27°29′E] | R. ELLENBERGER 1923” || Rectangle, white, printed text interspersed with handwriting: “PARATYPUS | Trox | instabilis sp.n. | det.Dr.E. HAAF 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”. Paratype 1♂ ( RBINS, aedeagus extracted, examined through detailed photographs available at https://virtualcollections.naturalsciences. be/virtual-collections/entomology/coleoptera/trogidae/trox-instabilis-haaf-1953): Rectangle, faded blue cardstock, printed black text, with two white labels glued to faded blue cardstock, first white label with handwriting, second white label with printed text: Coll . R. I. Sca. N. B. | South Africa || 1st white label: “Orange | F. State” || 2nd white label: “EX MUSEO | N VAN DE POLL” || Rectangle, faded red, printed text framed: “Para- | type” || Rectangle white, printed text interspersed with handwriting: “ Trox ” | instabilis Haaf | det.Dr.E. Haaf 1953 ” || Rectangle white, printed text interspersed with handwriting: “ TROX | sulcatus Thunb. | det. C.H. SCHOLTZ 1979 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”. Paratype 1♀ ( MNHN): Rectangle, faded blue cardstock, printed text: “MUSEUM PARIS | BASOUTOLAND [ Lesotho] | MASERU | R. ELLENBERGER 1923” || Narrow rectangle, red: “PARATYPE” || white square: “♀” || Rectangle, white, printed text interspersed with handwriting: “ Trox | instabilis Haaf | det.Dr.E. HAAF 1953 ” || Rectangle, white, printed text interspersed with handwriting: “ TROX | sulcatus Thunb. | det. C.H. SCHOLTZ 1980 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”. Paratype 1♀ ( MNHN): Rectangle, faded blue cardstock, printed text: “MUSEUM PARIS | ANCIENNE COLLECTION” || white square: “♀” || Narrow rectangle, red: “PARATYPE” || Rectangle, white, printed text interspersed with handwriting: “ Trox | instabilis Haaf | det.Dr.E. HAAF 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ” . Paratype 1 unsexed ( HNHM): Rectangle, yellowing white, printed text with handwriting: “Africa m. [meridionalis; probably present-day North West province, South Africa]” | coll. Staudinger ” || Rectangle, yellowing white, printed text with handwriting: Trox | sulcatus | det. J. Frivaldszky || Rectangle, white, printed text with handwriting: Trox | sulcatus | Thoms. | det. Dr.Endrődi || Red cardstock, printed text: “PARATYPE” || Rectangle, yellowing white with black border, printed text with handwriting: “631 | 12” || Rectangle, red framed card, printed text with handwriting: “Paratypus” | Trox | instabilis | Haaf” || Rectangle, white, printed text interspersed with handwriting: “ Trox | instabilis Haaf | det. Dr.E. Haaf 1953 ” || Rectangle, white cardstock with black margin: “ Phoberus instabilis | ( Haaf, 1953) | stat. rev., comb. nov. | det. Strümpher et al. 2023 ”.

Remarks. Haaf (1953) described Trox instabilis from 23 individuals. We studied the entire type series, which includes the male holotype (NHMB) and 22 paratypes (7 NHMB; 1 FMNH; 2 TMSA; 4 MNHN; 1 RBINS; 4 NHRS; 1 SDEI; 1 NHMW, 1 HMNH). According to the current treatment, the original type series comprises three distinct species. Eleven paratypes belong to Phoberus instabilis revalidated and new combination, nine belong to Phoberus sulcatus (this study), and two belong to the new species described herein.

Additional material with precise localities examined (502 specimens). ZIMBABWE: Mashonaland Central. 1♂ Mazowe [17°31′S 30°58′E], 1895, Darling ( SAMC) . Matabeleland North. 1♂ Victoria Falls , [17°55′S 25°51′E], 10.iv.1927, RHR Stevenson ( SAMC) . Bulawayo. 1♂ Khami , [20°09′S 28°25′E], 2.xi.1954 ( SAMC) . 1♀ idem but 25.xi.1955 ( SAMC) . 1♂ Bulawayo [20°10′S 28°35′E], 18.xi.1929, RHR Stevenson ( TMSA) . BOTSWANA: Central District. 1♂ Serowe 5 km SE, Farmers Brigade, near Swaneng Hill , [22°24′44″S 26°45′32″E], 20.x.1988, light trap, P Forchhammer ( SAMC) . 1♀ idem but ix.1989, Malaise trap ( SAMC) . 1♀ Serowe 4 km S, Swaneng Hill School , [22°24′47″S 26°44′54″E], mercury vapour lamp, P Forchhammer ( CMNC) . SOUTH AFRICA: Limpopo. 1♀ Soutpansberg, Ingwe Motel [now Ingwe Ranch], 22°58′S 29°56′E, 1,200 m, 23–24.xi.1992, H Hölzel, P Ohm, MW Mansell ( SANC) . 1♂ Soutpansberg, near Vivo, Goro Research Camp , 22°59′S 29°26′E, 19.iii.2018, light trap, WP Strümpher ( TMSA) . 1♀ Soutpansberg, Lajuma Research Centre , [23°02′S 29°26′30″E], 16.i.2016, C Munyai, P Tshililo ( TMSA) . 2♂, 3♀ Soutpansberg, Schoemansdal [environmental education centre], [ca. 23°01′S 29°43′E], 2.v.1977 , CH Scholtz ( SAMC) . 1 spec. unsexed idem ( CMNC) . 1 spec. unsexed idem ( RMCA) . 1♂ Louis Trichardt [23°03′S 29°54′E], 6.ii.1952 ( SAMC) . 3♂, 3♀ Vivo 21 km N, Blouberg Nature Reserve , 23°01′S 29°04′E, 991 m, 20.xii.2003, A Frolov, C Deschodt ( TMSA) . 2 unsexed Blouberg at Blouberg settlement, 23°05′S 28°59′E, 1,680 m, 4–7.xii.1990, SL Chown, HE Steenkamp, MA McGeogh ( SANC) . 1♂ Polokwane , [23°54′S 29°27′E], JP Cregoe ( SAMC) . 1♂ Mookgophong, Bundy Lodge , 24°27′S 28°42′E, 29.x.2004, WP Strümpher ( SAMC) . 1♂ Waterberg, Meletse [farm], 24°36′S 27°39′E, 13.ii.2016, R Müller ( TMSA) . 1♂ Thabazimbi, Ben Alberts Nature Reserve , 24°37′S 27°23′E, 24–28.xi. 1980, SJ van Tonder ( SANC) . 1♂ Mookgophong, Nylsvley Nature Reserve , 24°39′S 28°42′E, 28.xi.1979, E Grei ( SANC) . 1♀ idem but ix.1980 ( SANC) . 1♂, 1♀ Radium, Langkuil Private Game Farm , 20 km S Warmbad; ca. 25°02′S 28°11′E], T Beyers ( TMSA) . Mpumalanga. 1♂ Kruger National Park, Skukuza Rest Camp [24°59′S 31°36′E], xii.1977 , CH Scholtz ( SAMC) . 1♀ Siyabuswa , 25°07′S 29°03′E, 21.ii.1998, Poto ( TMSA) . 1♀ Roossenekal , Booysensdal Mine North, 25°07′S 30°08′E, 25.x.2000, E-Y:3435, at light, Museum staff ( TMSA) . 1♂ Stofberg, Laersdrif , [25°22′S 29°51′E], 8–13.xi.1974, J Dedman ( SAMC) . 1♂ Mbombela , De Hoop 203 [farm], [ca. 25°32′S 31°09′E], 20–21.xi.1972, A Strydom ( TMSA) . 1♀ Barberton, Saddleback Hill [ca. 25°47′S 31°05′E], Barberton, xii.1998, van Viegen ( TMSA) . 7♂ Lake Chrissie farm, 5 km SE of Chrissiesmeer, 26°18′S 30°15′E, 1,700 m, 26.xi.2002, in remains of dead sheep, R Stals ( SANC) . Gauteng. 1♂ Bronkhorstpruit, Ezemvelo Nature Reserve , 25°42′S 29°01′E, 1,374 m, 26.i.2004, E-Y:3605, light trap, TMSA staff ( TMSA) . 1♂ idem but 27.i.2004, E-Y:3606, pitfall trap, R Müller ( TMSA) . 1♀ Bronkhorstpruit, Rhenosterpoort Private Nature Reserve , 25°45′S 28°58′E, 19.ii.1975, PS Pots & MJ Scoble ( TMSA) . 2♂, 1♀ idem but 16.xi.1975, E-Y:937, bushveld, sifted from litter, S Endrödy-Younga ( TMSA) . 1♀ Boekenhoutskloof [farm], 25°31′S 28°26′E, 25.iii.1994, J Harrison ( TMSA) . 2♀ Pretoria 25 km E, Bashewa Plot 12, 25°56′S 28°24′E, 1,550 m, 28.xii.1995, R Stals ( SANC) . 1 unsexed Pretoria, Roodeplaat [ARC experimental farm], 25°36′S 28°21′E, 22.xi.1979, M Bolton ( SANC) . 1♂ idem but x.1979, C Kok ( SANC) . 1♀ idem but xi.1979, SJ van Tonder ( SANC) . 1♀ 1♂ Pretoria, Shere [25°48′S 28°21′E], 27.x.1963, R Hofman ( TMSA) . 1♀ Pretoria , [ca. 25°44′S 28°13′E], xi.1924, HJ Heske ( TMSA) . 11♂ idem but 5.iii.1931, C.S. ( SAMC) . ♂ idem but 5.iv.1932, DHB ( SAMC) . 1♀ Pretoria , 1.1.1975, L Schulze ( TMSA) . 1♀ Pretoria North, 25°41′S 28°11′E, ix.1937, G van Son ( TMSA) . 4♂, 2♀ Pretoria, Onderstepoort Nature Reserve, Kaalplaas , [25°38′S 28°10′E], 11–16.v.1977, J Boomker ( SAMC) . 2 spec. unsexed idem but 16.v.1977 ( RMCA) . 2♂, 1♀ Broederstroom, Vlakplaas portion 53 [farm], Protea Ranch , [25°49′30″S 28°01′E], 2–15.xi.2008, M Paulsen ( TMSA) . 1♂ Johannesburg , [ca. 26°12′S 28°02′E], x.1901 ( TMSA) . 1♂ idem but xii.1934, G Kobrow ( SAMC) . 1♂ idem but 30.xii.1945, A Capener ( TMSA) . 1♀ idem but iii.1963, F Zumpt ( NHMB) . 1♀ Johannesburg, Klipriviersberg Municipal Nature Reserve [26°18′S 28°01′E], 3.xi.2013 ( TMSA) . 1♂, 1♀ West Rand District Municipality, Nascott Game Park [now John Nash Nature Reserve,], 25°54′S 27°46′E, pitfall traps: 1.xi.1985, E-Y:2567, G du Plessis ( TMSA) . 1♀ idem but 28.xi.1985, E-Y:2568 ( TMSA) . 1♀ idem but 3.iii.1986, E-Y:2571 ( TMSA) . 2♀ idem but 17.iv.1986, E-Y:2572 ( TMSA) . 1♂ idem but 14.viii.1986, E-Y:2574 ( TMSA) . 1♂ idem but 1.xi–29.xi.1985 ( TMSA) . 1♂ idem but 23.ix–23.xi.1986 ( TMSA) . 1♂ Krugersdorp Game Reserve [26°06′S 27°43′E], 30.ix.2008, light trap, E Pretorius ( TMSA) . 1♂, 2♀ Vereeniging , [26°40′S 27°56′E], 15.xii.1915 ( SANC) . North West. Hartbeespoort, Daspoortrant, Saartjiesnek [25°46′S 27°56′E], ii.1978, E Holm ( SAMC) . 1♂ Hartbeespoort , [ca. 25°44′S 27°53′E], i.1961, E Holm ( SAMC) . 1♀ Rustenburg, Buffelspoort Dam , 25°47′S 27°29′E, 9.x.1983, RG Oberprieler ( SANC) . 1♀ Rustenburg Nature Reserve , 25°40′S 27°12′E, 17–20.iii.1980, WA Harrop ( SANC) . 2♀ Venterskroon, Vredefort Dome , 26°50′S 27°19′E, 1,388 m, 19–20.ii.2012, E-Y:3934, disturbed habitat, R Müller ( TMSA) . 1♂, 1♀ idem but E-Y:3935, at light ( TMSA) . 1♀ Potchefstroom [ca. 26°43′S 27°05′E], 28.xii.1976, TW Drinkwater ( SANC) . 1♂ idem but 7.i.1977 ( SAMC) . 1♂ idem but 5.iii.1988, AE Gildenhuys ( SAMC) . 1♀ Koster , 25°52′S 26°54′E, 16.xi1993, R Stals, M Vogt, F Joubert ( SANC) . 1♂ Zeerust 23 km NE, Meseg, Enzelsberg , 25°22′S 26°14′E, 20–22.ii.2009, 1,300 m, CD Theron ( CEMT) . Northern Cape. 1♂ Jan Kempdorp , [ca. 27°55′S 24°50′E], i.1961, H.S. ( SAMC) . 2♂, 1♀ Barkly West, Sydney on Vaal , 28°27′S 24°19′E, 7–9.iii.1990, S Louw ( BMSA) . 1♂ Barkly West, Vaalbos National Park [deproclaimed], 28°34′S 24°18′E, 7–9.iii.1990, S Louw ( BMSA) . 1♀ Kimberley , [ca. 28°43′S 24°45′E], 30.i.1948, RJ Power ( SAMC) . 1♂ idem but 3.iv.1948 ( SAMC) . 1♀ Kimberley, Dronfield Nature Reserve [ca. 28°37′S 24°48′E]. 1.iv.2023, H de Klerk ( TMSA) . 1♀ Kimberley, Riverton [28°31′S 24°42′E], 16.xi.1961, HAD van Schalkwyk ( SANC) . 1♀ Kimberley, Langeberg 138 [farm], 28°55′S 24°36′E, pitfall traps: xi.1987 – iii.1988 ( BMSA) . 1♂, 2♀ Schmidtsdrif, Rooipoort [farm], 28°38′S 24°16′E, 1,129 m, 3.iii.2009, E-Y:3847, Kalahari bushveld, light trap, D MacFayden, R Müller ( TMSA) . 1♀ Schmidtsdrif , [28°42′S 24°03′E], 2.x.1954, G van Son ( TMSA) . 1♂ Kuruman [27°28′S 23°25′E], 8.iv.1933, G van Son ( TMSA) . 1♀ Sishen 5 km S, 27°50′S 22°59′E, xi.1996, light at night, E Holm ( SANC) . 1♀ Groblershoop , 28°53′S 21°59′E, 1–7.iv.1980, CG Moolman ( SANC) . Free State. 1♀ Sasolburg , 26°49′S 27°49′E, 20.xi.1988, N Duke ( SANC) . 1♂ Parys 4 km E, Abel 52 [farm], 26°54′S 27°35′E, 4–7.xii. 1992, M Krüger ( TMSA) . 1♂ Koppies , [27°14′S 27°35′E], 1.i.1982, RS van Zyl ( BMSA) . 1 unsexed Heilbron, Uitsien 1449 [farm], SE 2727 Db , 26–30.xii.1982, A van Rensburg ( BMSA) . 1♀ Bothaville , [27°24′S 26°37′E], 30.iv.[18]99, Dr Brauns ( TMSA) . 4♂, 2♀ Bothaville, Deelfontein 482 [farm], 27°07′S 26°35′E, 12–22.iv.1977, GW & MC Ferreira ( BMSA) . 1♂, 1♀ idem but 13–17.ix.1978,A Strydom ( BMSA) . 10♂, 16♀ idem but viii–x.1986 ( BMSA) . 1♂ Kroonstad [27°40′S 27°14′E], 17.i.1965, DJ Brothers ( TMSA) . 1 spec. unsexed Lindley, Middelpunt 760 [farm], 28°05′S 28°00′E, ix.1985, A van Wyk ( BMSA) . 1♂ Hoopstad, Sandveld Nature Reserve , [ca. 27°38′S 25°41′E], 8–12.ii.1982, Entomology Dept. ( BMSA) . 1♀ Hoopstad, Swartsrus 1193 [farm], 27°45′S 25°30′E, iv.1985, Entomology Dept. ( BMSA) . 6♂, 2♀ Hoopstad, Sophiasdal 280 [farm], [ca. 27°54′S 25°45′E], 7–8.ii.1978, A Strydom ( BMSA) . 1♀ idem but 4.iii.1978 ( BMSA) . 1♀ idem but iii–v.1982 ( BMSA) . 1♂ Bultfontein, Hartenbosch 43 [farm], [ca. 28°17′S 26°01′E], 1–2.ii.1978, A Strydom ( BMSA) . 3♂, 2♀ Boshof , [28°32′S 25°14′E], 4.xii.1976, E Holm ( SAMC) . 1♂ idem ( RMCA) . 1 spec. unsexed idem but CH Scholtz ( CMNC) . 1 spec. unsexed Boshof 20 km W, [ca. 28°32′S 25°01′E], 12–14.xii.1984, H Howden ( CMNC) . 9♂, 9♀ Voorspoed 1585 [farm], near Boshof, SE 2825 Cd [ca. 28°52′S 25°46′E], 21–28.iii.1977, A Strydom ( BMSA) . 1♀ idem but 15–16.ii.1978 ( BMSA) . 2♂, 2♀ Boshof, Wesselsdam 379 [farm], near SE 2825 Ba [ca. 28°09′S 25°36′E], 15–16.ii.1978, A Strydom ( BMSA) . 1♀ idem but 21–28.iii.1977 ( BMSA) . 1♀ Winburg [ca. 28°31′S 27°01′E], v.[19]07, H Fry ( TMSA) . 6♂, 4♀ Vrede, Beginsel 1284 [farm], Vrede , [ca. 27°26′S 28°44′E], 9–15.ii.1979, A Strydom ( BMSA) . 1♀ Harrismith, Greenlands 1245 [farm], 28°16′S 28°59′E, 17–17.xii.1984, A van Rensburg ( BMSA) . 4♂, 1♀ Harrismith, Kerkenberg , [28°30′S 29°08′E], 1–12.ii.1977, GW & MC Ferreira, A Strydom ( BMSA) . 38♂, 30♀ 126 spec. unsexed Ladybrand, Nova 667 [farm], [29°07′S 27°22′E], 1–12.ii.1977, GW & MC Ferreira, A Strydom ( BMSA) . 1♂, 1♀ idem but 19–22.i.1976, GW Ferreira & Ee ( BMSA) . 1♂ idem but 15– 26.v.1978, GW Ferreira & A Strydom ( BMSA) . 1♂, 3♀ Mowbray 287 [farm], near Ladybrand, SE 2927 Ab , 18– 29.ix.1978, Museum staff ( BMSA) . 4♂, 6♀ Groenkloof 294 [farm], near Ladybrand, SE 2927 Ab , 1–12.ii.1977, GW & MC Ferreira ( BMSA) . 1♂, 1♀ idem but 18–29.ix.1978, Museum staff ( BMSA) . 1♂, 1♀ Winnie Mandela, Florisbad 686 [farm, research station] [28°46′S 26°04′E], i.1984, Entomology Dept. ( BMSA) . 1♀ idem but xii.1984 ( BMSA) . 1♀ idem but iv.1985 ( BMSA) . 2♂, 1♀ idem but ix.1985 ( BMSA) . 2♀ idem but x.1985 ( BMSA) . 2 spec. unsexed idem but 9–12.xii.1984, H & A Howden ( CMNC) . 5♂, 6♀ Bloemfontein, Glen [farm, agricultural college], 28°56′S 26°20′E, 18.x.1983, Van Rensburg & Earlé ( BMSA) . 2♂, 3♀ idem but 22–30.iii.1977, A Strydom ( BMSA) . 4♂, 4♀ idem but 5.iv.1978 ( BMSA) . 2 spec. unsexed Bloemfontein , [ca. 29°07′S 26°13′E], 15.ii–14.iii.1976, Museum staff ( BMSA) . 1♂, 1♀ Bloemfontein, Free State National Botanical Garden , [ca. 29°03′S 26°13′E], ii.2006, Museum staff ( BMSA) . 2♂ Bloemfontein, Monument 2206 [farm], SE 2926 Ac , 7.xii.1976, A Strydom ( BMSA) . 1♂ idem but 17–18.viii.1983 ( BMSA) . 4♂, 5♀ Bloemfontein, Merino 14 [farm], [ca. 28°52′S 26°12′E], 29.xi– 3.xii.1976, A Strydom ( BMSA) . 1♀ Bloemfontein, The Willows 5837 [farm], 29°14′S 26°05′E, 8.ix.1983, Van Rensburg & Earlé ( BMSA) . 1♂, 1♀ Fauresmith, Zuurfontein 92 [farm], [ca. 29°55′S 25°24′E], 19–22.i.1982, JH van Wyk ( BMSA) . 1♂, 1♀ Philippolis, Allemans Drift 37 [farm], [ca. 30°32′S 25°20′E], 23–29.x.1978, A Strydom ( BMSA) .

Redescription.

Size: Length: 9–12.5 mm. Width across humeri: 5.6–7.3 mm.

Body shape: Elongate oval, elytral margins subparallel, elytral profile somewhat flat to slightly convex, attaining maximum height in middle, declivous posteriorly.

Colour ( Figs 9–10 ): Matt black. Body setae mostly brownish yellow.

Head ( Figs 9–10 ): As in Phoberus sulcatus .

Pronotum ( Figs 9–10 ): As in Phoberus sulcatus , except pronotal tubercles and ridges are higher and more prominent, punctation appears denser, pronotal surface slightly more embossed.

Scutellum ( Fig. 9 ): Longer than wide, obround in shape; surface smooth; medio-basally depressed, depression punctate; margin smooth, tomentose.

Elytra ( Figs 9–10 ): Relative dimensions and margins as in Phoberus sulcatus , except that the profile is somewhat flatter. Humeral calli, and sutural margin as in Phoberus sulcatus . 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; tubercles on costae 2 and 4 irregularly spaced along elytral length, distance between tubercles roughly equal to or more than length of tubercles; tubercles on costae 6 and 8 widely spaced, distance between tubercles equal to or greater than length of tubercles; weak apical callosity present on fourth costal interval at top of elytral declivity. Elytral costae 2 and 4 with 7–9 tubercles for 0.75 elytral length (up to apical callosity).

Odd-numbered costae as in Phoberus sulcatus . Dorsally costae 1–4 separated from intercostae as slightly elevated bands; laterally costae 5–9 barely discernible as bands. Intercostae as in Phoberus sulcatus .

Metathoracic wings: Complete.

Ventral aspects: As in Phoberus sulcatus .

Male genitalia ( Figs 7 , 11 , 19, 22 ): Symmetrical, slender, strongly sclerotised. Phallobase, subovate in dorsal view, arched in lateral view, as long as or slightly shorter than parameres. In dorsal aspect parameres long, slender, extending well beyond phallus, attenuated inward, apex narrowed, pointed, always projecting forward (never inward or down) ( Figs 11 , 19d ). Parameres in lateral aspect evenly broad basally, sides subparallel, feebly sinuate apically ( Fig. 22r ; never convex or curved as in Fig. 21o ), moderately expanded medially (compare Fig. 22q with Fig. 21n ), apically slender, narrowed, apices long, only moderately decurved (almost straight, never strongly decurved or projecting downward as in Fig 21 m ), projecting forward ( Figs 22p ). Phallus divided into two symmetrical lobes ( Figs 11 , 19 ); lobes broad basally, inner halve of lobe there elevated, concave ( Fig. 19 ), lobes strongly narrowing in apical third, outside margin notched at apical third ( Fig. 19f ), apex of phallus narrow, apex broadly rounded and pointing inward, weakly keeled ( Fig. 19e ); inner margins of lobes almost parallel ( Fig. 19g ); two bladelike projections and hooks visible between parameres and phallus.

Differential diagnosis. Phoberus instabilis revalidated and new combination is the most similar to Phoberus sulcatus , but males can be distinguished from the latter by the following combination of characteristics: the parameres in lateral profile are broad, weakly expanded medially ( Fig. 22q ); their apices are long, narrow and weakly curved downward ( Fig. 22p ); and the dorsal margin at the apex is primarily straight and feebly concave ( Fig. 22r ). Furthermore, in Phoberus instabilis the lobes on the phallus are broad and not strongly concave as in Phoberus sulcatus (compare Figs 18 and 19 ). Also, see Table 1 for additional characteristics.

Geographic distribution. Phoberus instabilis is known from Botswana, Lesotho, South Africa and Zimbabwe ( Fig. 24 ). In South Africa, the species has been recorded from the Free State, Gauteng, Limpopo, Mpumalanga, North West and Northern Cape provinces.

Natural history. Based on label data, adult beetles have been collected at light in the night and from the remains of a dead sheep. Collection records show Phoberus instabilis to be active from August to May. 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).

FIGURES 6–8. Holotype of Trox instabilis Haaf, 1953 (NHMB): 6, habitus, dorsal view; 7, aedeagus, dorsal aspect; 8, holotype labels. Length of specimen: 12 mm. Photographs by Christoph Germann, copyright NHMB.

FIGURES 9–12. Phoberus instabilis (Haaf, 1953), revalidated and new combination, cleaned specimen (TMSA). 9, habitus, dorsal view; 10, habitus, lateral view; 11, aedeagus, dorsal and lateral views; 12, 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.