Polynoncus gemmiferus ( Blanchard, 1847 )

Costa-Silva, Vinícius, Strümpher, Werner P., Thyssen, Patricia J. & Vaz-de-Mello, Fernando Z., 2024, Taxonomic revision of the South American genus Polynoncus Burmeister, 1876 (Coleoptera: Scarabaeoidea: Trogidae), Journal of Natural History 58 (1 - 4), pp. 14-166 : 83-88

Polynoncus gemmiferus ( Blanchard, 1847)

( Figures 33–35 )

Trox gemmiferus Blanchard, 1847: 188 (original description)

Trox guttifer Harold, 1868: 86 (replacement name and validation – nomen novum); Harold 1869: 1088 (checklist); Harold 1872: 146, 190 (redescription); Burmeister 1876: 261 (as variety of T. gemmifer ); Preudhomme de Borre 1886: 73 (checklist, as variety of T. gemmifer ); Arrow 1912: 56 (as variety of T. gemmifer ); Blackwelder 1944: 218 (checklist, as variety of T. gemmifer ); Vaurie 1962: 124 (redescription)

Trox (Polynoncus) guttifer : Scholtz 1982: 16 (catalogue)

Polynoncus guttifer : Scholtz 1986a: 362 (systematics); Scholtz 1990: 1435 (redescription); Gómez 2008: 516 (key to Argentinean species); Zidek 2013: 11 (checklist); Zidek 2017: 102 (checklist – as ‘ gutifer ’)

Polynoncus gemmiferus : Zidek 2013: 10 (as n. praeocc.); Zidek 2017: 101 (as n. praeocc.); Smith 2017, p. 94 –95 (original spelling to species); Costa-Silva and Diéguez 2020: 272 (records from Argentina).

Type specimen examined. LECTOTYPE HERE DESIGNATED. (♀ MHNH – Figure 33 ) First label [white, aged, with black frame, typeset]: ‘MUSEUM PARIS / PATAGONIE / (PATAGONES) / D’ORBIGNY 1834’. Second label [rounded, d’Orbigny’s handwriting]: ‘6031 / 34’. Third label [white, aged, d’Orbigny’s handwriting]: ‘1032’. Fourth label [white]: ‘ ♀ ’. Fifth label [green with black bars on each side, Émile Blanchard’s handwriting]: ‘margaritiferus / Bl’. Sixth label [red with black frame, printed]: ‘ LECTOTYPE / Trox gemmiferus / Blanchard 1847 / des. V. Costa-Silva, 2022’. Seventh label [white with black frame, Vinícius Costa-Silva’s handwriting]: Polynoncus ♀ / gemmiferus / ( Blanchard, 1847) / Det. V. Costa-Silva, 2022” ( Figure 33c ). Type locality: ‘Patagones’ [Village de Patagones] (= Viedma), Río Negro ( Argentina), collected by A. d’Orbigny between January and September 1829. According to the d’Orbigny catalogue (number 1032), these individuals are found in sandy and dry places, hiding beneath or inside carcasses; at night they are more active searching for food resources.

Differential diagnosis. Even though the confluent pattern of elytral tubercles in P. gemmiferus resembles that of P. pampeanus , the presence of humeral calli and distinct basal tubercles on the pronotum easily separate the former from the latter.

Vaurie (1962), in her revision of South American Trogidae , cited and illustrated a variation on the basal tubercles of the pronotum ( Vaurie 1962, p. 125). According to the author, there are two forms of basal tubercles on the pronotum: one with the basal tubercles and pronotal ridges distinctly separate ( Figure 34a ), and another with basal tubercles broader and partly fused to the pronotal ridges ( Figure 34b ). After examining and dissecting more than 90 specimens, we concluded that this characteristic is, in fact, a marked sexual dimorphism of P. gemmiferus , where the males, which are generally larger in size, have the basal tubercle much thinner and widely separate from the pronotal ridges, while in females these basal tubercles tend to be broader and weakly fused to the pronotal ridges (see Figure 34 to comparison).

Geographic distribution. Polynoncus gemmiferus is widely distributed in Argentina, with a single record from Paraguay ( Figure 35 ). Vaurie (1962) examined one specimen from Chile without specific locality data; however, this specimen could not be traced by us.

Examined non-type material (317 specimens). ARGENTINA: Buenos Aires, Bahía San Blas, no date or collector (1 MACN) ; Carmen de Patagones, no date or collector (1 MLPA) ; Carmen de Patagones , no date or collector [Burmeister’s collection] (1 MACN) ; La Plata, no date, A.R. Bezzi leg. (1♂ and 1♀ MLPA) ; Tapalqué , no date or collector [Bruch’s collection] (2 MACN). Chubut, Epuyén ,[N.-W.Patagonia (sic!)], 300–900 m, December 1919,H.E. Box leg.(3♂ BMNH) ; Península Valdés , 1 March 1998, D. Rojas Lanus leg. (1♂ and 3♀ CVMD) ; Península Valdés , January 2004, Carlos H. Ferreira leg. (1♀ MZSP) ; Península Valdes, Punta Delgada , February–March 1998, Daniel Rojas Lanus leg. (2♂ and 13 unsexed CVMD) ; Península Valdes, Punta Delgada , February–March 1998, Daniel Rojas Lanus leg. (1♂ and 1♀ MUSM) ; Río Senguer, Río Mayo , 30 January 1997, F. Ricci leg. (1♂ and 1♀ CVMD) ; Río Senguer, Río Mayo , 30 January 1997, J. Mondaga leg. (1 CVMD) ; Sarmiento, Colhué Huapi, Cerro Negro , 15 February 1927, no collector [Bruch’s collection] (1 MACN) ; Tehuelches , 3 km NE Libertador San Martín, 721 m, 17 November 2014, V. Silvestro, R. Carrara, G. Cheli, G. Flores leg. (1♀ IADIZA) ; Telsen , 3 February 2011, under Guanaco [ Lama guanicoe ] carcass, G. Arriagada leg. (1♀ CVMD) ; Valle del Lago Blanco ,1903, no collector (1♀ BMNH) ; without specific locality,date or collector (1 MLPA) ; without specific locality, date or collector [Bruch’s collection] (1 MACN) ; without specific locality or date,G. Pellegrano leg. (3 MACN) ; without specific locality or date,H. Richter leg. (1 MLPA) ; without specific locality or date, H. Richter leg. (2♂ and 1♀ MLPA). Córdoba, without specific locality, date or collector [Burmeister’s collection] (1 MACN). Entre Rios, Pueblo Liebig , December 1997, Mateo Zelich leg. (1♂ CVMD). La Rioja, Ruta 60, 5 February 2002, horse carcass, C. Medina leg. (2♂ UPTC). Mendoza, 17 km E Refugio Alvarado, Reserva Laguna del Diamante , 1704 m, 34.256°S, 69.201°W, 19 November 2012, horse carcass, Gerardo Arriagada leg. (2♂ and 3 unsexed CVMD) ; Desaguadero , 9 January 2000, S. Esparza leg. (1♀ CVMD) ; Dique El Nihuil , 10 January 1980, Willink, Fidalgo, Claps y Domingos leg.(4♀ IFML) ; Dique El Nihuil , March 2002,C. A Medina leg.(1♂ and 1♀ CEMT) ; Isla Cochicó,no date or collector (1 MLPA) ; Malargüe, Reserva Natural La Payunia, Puesto La Senillosa , 20 February 1998,A. Atencio leg.(1♂ IADIZA) ; Malargüe, Reserva Natural Payunia , 1575 m, 35.999° S, 68.881°W, 2 December 2015, horse carcass, F. Aballay leg. (1♀ IADIZA) ; Malargüe, Reserva Natural Payunia , 2028 m, 35.679°S, 68.694°W, 6 January 2016, F. Aballay leg. (9♂ and 6♀ IADIZA) ; Malargüe, Reserva Natural Payunia, Puesto Mina Ethel, 1672 m, 36.001°S, 68.836°W, 4 January 2016, F. Aballay leg. (2♂ and 3♀ IADIZA) ; San Carlos, Reserva Laguna del Diamante , 1800 m, 31 December 2014,F. Aballay and F.Jofré leg. (2♂ and 6♀ IADIZA) ; San Carlos, Reserva Laguna del Diamante , 1800 m, 31 December 2015, F. Aballay and F. Jofré leg. (10♂ and 9♀ IADIZA) ; San Carlos, Reserva Laguna del Diamante , 2200 m, 31 January 2015, F. Aballay leg.(2♂ and 4♀ IADIZA) ; San Rafael , 1 February 1979, Sergio Roig leg. (1♀ IADIZA) ; San Rafael , no date, Sergio Roig leg. (2♂ IADIZA) ; Santa Rosa, Reserva de Biosfera de Ñacuñán , 10 March 2014, collected with light trap, G. Arriagada leg. (1 CVMD) ; Santa Rosa, Reserva de Biosfera de Ñacuñán , 11–13 December 2002, V.M. Diéguez leg. (3♂ and 1♀ IADIZA) ; Santa Rosa, Reserva de Biosfera de Ñacuñán , 11–13 December 2002, V.M. Diéguez leg. (4 CVMD) ; Santa Rosa, Reserva de Biosfera de Ñacuñán , 16 February 1982, S. Claver leg. (1♂ and 1♀ IADIZA) ; Santa Rosa, Reserva de Biosfera de Ñacuñán , 3 December 1981,S. Claver leg.(2♂ IADIZA) ; Santa Rosa, Reserva de Biosfera de Ñacuñán , January 1976, Sergio Roig leg.(1♀ IADIZA) ; Villa San Carlos ,no date or collector (1 MACN) ; without specific locality or date, P. Strobel leg. (1♂ and 1♀ MNHN) ; without specific locality,date or collector (3♂ MNHN) ; without specific locality,date or collector (3 MLPA) ; without specific locality,date or collector [Burmeister’s collection] (1 MACN) ; without specific locality, date or collector [ Burmeister’s collection] (1 MACN) ; without specific locality or date, H. Richter leg. (2 MLPA) ; without specific locality or date, H. Richter leg. (1♀ CEMT) ; without specific locality, November 1946, Moyano leg. (1♂ and 1 unsexed IFML). Neuquén, Bajada Marucho , 650 m, 21 March 1974, M. Gentili leg. (3♀ IADIZA) ; Bajada Marucho , 870 m, 4 December 1972, M. Gentili leg. (1♂ IADIZA) ; Confluencia, Estación Challacó , 1900, Dr Schiller leg. [Bruch’s collection] (1 MACN) ; Lácar, Río Caleufú , November 1964, D. Giai leg. (1 CVMD) ; Laguna Blanca National Park , 1270 m, 21 February 1966, M. Gentili leg. (1♀ IADIZA) ; Laguna Blanca National Park , 1270 m, December 1965, A. Giai leg. (4♀ IADIZA) ; Laguna Blanca, 20 January 1971, no collector (1♂ JZPC) ; Lotena, Granito , 800 m, 13 October 1971, M. Gentili leg. (1♂ IADIZA) ; Piedra del Aguila , 525 m, 7 February 1992, M. Gentili leg. (1♀ IADIZA) ; Plaza Huincul, 5 April 1920, no collector [Bruch’s collection] (1 MACN) ; Plaza Huincul , 600 m, 21 October 1970, M. Gentili leg. (1♀ IADIZA) ; Reserva Provincial Auca Mahuida, El Cruce , 600 m, 9 October 1982, M. Gentili leg. (1♀ IADIZA) ; Río Limay, no date or collector (3 MLPA) ; Sañico , 900 m, 14 March 1972, M. Gentili leg. (2♀ IADIZA) ; Santo Tomas , 600 m, 5 October 1972, M. Gentili leg. (1♀ IADIZA) ; without specific locality, 1900, Weiske leg. (1 MLPA) ; without specific locality,1907, Dr Adolf Lendl leg. (2♂ MNHN) ; without specific locality or date, H. Richter leg. (4 MLPA) ; Zapala , 15–21 July1949, Monrrós leg.(1♂ and 1♀ IFML) ; Zapala , 18–22 December 1946, Hayward y Willink leg. (1♂ and 3♀ IFML) ; Zapala, Catutoa , 1080 m, 17 February 1968, M. Gentili leg. (2♀ IADIZA) ; Zapala, Villa Militar de Covunco 29 October 1962, M. Gentili leg. (2♀ IADIZA). Rio Negro,Aguada Cecílio,no date or collector (15 MLPA) ; Aguada Cecílio, no date or collector (9 MLPA) ; Cerro Tapiluque , 19 March 1915, no collector (17 MLPA) ; Cerro Tapiluque,no date or collector (20 MLPA) ; Cerro Tapiluque, no date or collector (4♀ CEMT) ; Ministro Ramos Mexía Corral Chico , no date or collector (30 MLPA) ; Pichi Mahuida , Rio Colorado , December 1930, [J. Bosq’s collection] (1 MLPA) ; Pichi Mahuida , Rio Colorado , December 1930, A. Breyer leg. (5 MACN) ; Village de Patagones [= Viedma], February 1829, d’Orbygni leg. (1♀ MNHN) ; without specific locality, 1900, [Bruch’s collection] (1 MLPA) ; without specific locality, date or collector (2♂, 4♀ and 2 unsexed MACN). Santa Cruz, Deseado, Punta Peligro [also called Punta Maqueda], November 2005, no collector (1♀ IADIZA) ; Puerto Deseado , February 1962, no collector (3 MACN) ; without specific locality, date or collector [Bruch’s collection] (1 MACN). Tucumán,without specific locality, January–February 1884,L. Dormer leg.(1♀ BMNH) ; without specific locality, date or collector (1♂ and 1♀ MNHN). Without specific locality, ‘ Patagonie’, Aucey [?] leg. (1♀ MNHN) ; ‘ Patag’, no date or collector (1♀ MNHN). PARAGUAY: Capital District , Asunsión, no date or collector (2♂ RBINS).

Remarks. The name Polynoncus guttifer was proposed by Harold (1868) to replace the name Trox gemmiferus Blanchard, 1847, p. 188 to avoid the homonym with Trox gemmiferus Blanchard, 1847, p. 187 . As first mentioned by Smith (2017), the valid name for the species is Trox gemmiferus (currently Polynoncus gemmiferus ) and should be used as a nomenclatural priority according to the International Code of Zoological Nomenclature (ICZN, 1999; for details, see Smith 2017). We agree with Smith’s (2017) conclusions.

Note. After examining the type of Trox gemmiferus (not examined by earlier authors), it became clear that the mistake made by Blanchard (in naming two species with the same spelling) was made only in the writing of the manuscript. According to the label found on the type species, Blanchard intended to name the species ‘ margaritiferus ’, as can be seen in Figure 33c .

Figures

Figure 33. Lectotype of Trox gemmiferus Blanchard, 1847 (now Polynoncus gemmiferus), here designated: habitus in a, dorsal and b, lateral view; c, labels. Scale bar: 1 mm.

Figure 34. Sexual dimorphism in Polynoncus gemmiferus (Blanchard, 1847): a, male, pronotal ridges thin and distinctly separated from the basal tubercles; and b, female, pronotal ridges broader and connected with the basal tubercles. Scale bar: 1 mm.

Figure 35. Distribution map of Polynoncus gemmiferus (red circles), P. gibberosus (green triangles), and P. juglans (blue squares) in South America. The records with a black dot in the centre indicate the type locality of the respective species.