Polynoncus patagonicus ( 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 : 119-121

Polynoncus patagonicus ( Blanchard, 1847)

( Figures 5g , 46 , 52 )

Trox patagonicus Blanchard, 1847: 186 (original description); Lacordaire 1856: 152 (checklist); Harold 1869: 1089 (checklist); Harold 1872: 188, 191 (citation); Berg 1881: 99 (checklist of Rio Negro, Argentina); Preudhomme de Borre 1886: 74 (checklist); Burmeister 1876: 254 (redescription); Felsche 1901: 154 (new synonym of T. bullatus ); Bruch 1911: 193 (checklist – as synonym of T. bullatus ); Arrow 1912: 54 (catalogue – as junior synonym of T. bullatus ); Blackwelder 1944: 218 (checklist – T. ‘ patagonica ’ as synonym of T. ‘ bullata ’); Vaurie 1962: 141 (redescription and reinstated as a valid species)

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

Polynoncus patagonicus : Scholtz 1986a: 362 (systematics); Scholtz 1990: 1423 (redescription); Gómez 2008: 515 (key to Argentinean species); Zidek 2013: 14 (checklist); Zidek 2017 (checklist); Smith 2017: 98 (lectotype designated); Costa-Silva and Diéguez 2020: 272 (records from Argentina)

Type specimen examined. LECTOTYPE. (♀ MNHN – Figure 52 ) First label [white]: ‘ ♀ ’. Second label [white, aged, typeset]: ‘MUSEUM PARIS / PATAGONIE / (PATAGONES) / D’ORBIGNY 1834’. Third label [white, aged, D’Orbigny’s handwriting]: ‘1028’. Fourth label [rounded, handwritten]: ‘6097 / 34’. Fifth label [green with a black line on each side, handwritten]: ‘ Trox / patagonicus / Blanch’. Sixth label [red, typeset]: ‘LECTOTYPE’. Seventh label [red with black border, Andrew Smith’s handwriting]: “ TROX / PATAGONICUS / Blanchard 1847 / LECTOTYPE / A.B.T. SMITH [typeset]. Eighth label [white with black border]: ‘SCARABS OF / SOUTHERN / SOUTH AMERICA / SSSA3001570’ ( Figure 52c ). Type locality: ‘ Patagones’. According to the entry 1028 in d’Orbigny’s collection catalogue, this specimen was collected in the mouth of Río Negro ( Argentina) under a cow carcass in March 1829 (for details of d’Orbigny’s catalogue, see Smith 2017) .

Differential diagnosis. Polynoncus patagonicus is the largest species of the genus (~ 17– 22 mm). It is morphologically similar to P. bullatus and P. patriciae . It can be easily separated from these two species by having a raised transverse ridge connecting the pronotal ridges and anterolateral tubercle ( Figure 5g , white arrows).

The general morphology of the median lobe of all three species is similar,although the apex shape is distinctive: P. patagonicus has the apex sinuous; P. patriciae has a strong emargination that is U-shaped (almost bifurcate) and anterior angles rounded, and P. bullatus is smoothly emarginate with anterior angles acute. For a more detailed comparison, see Pittino (1987).

Geographic distribution. Polynoncus patagonicus is widely distributed in Argentina ( Figure 46 ). Vaurie (1962) mentioned one female specimen from Pará ( Brazil), without further information about specific locality or the depository of the examined material (see Smith 2017). Also, we examined in BMNH one specimen from ‘Bolívia’ without further data. Based on our understanding of the geographical distribution of these species, these improbable records need to be treated with caution.

Examined non-type material (40 specimens). ARGENTINA: Buenos Aires, Bahía Blanca, C . Darwin leg . (4 BMNH); Bahía Blanca, no date or collector (1 CEMT); Saavedra , 5 August 1923 (1 MLPA); without specific locality or date [Bruch’s collection] (1 MACN) . Chubut, Península Valdes, Punta Delgada, 2 November 1997, Daniel Rojas Lanus leg . (1 CVMD); Valdés , 8 km S Punta Norte, 42 m, 42.205°S, 63.868°W, 14 January 2010, G . Flores, G . Cheli y R . Carrara leg . (1 IADIZA); Valdés, Puesto Abandonado , 42.717°S, 63.640°W, 23 February 2007, G . Cheli leg . (1 IADIZA); without specific locality or date [ Bruch’s collection] (2 MACN); without specific locality or date, G . Pellerano leg . (4 MACN); without specific locality or date, H . Richter leg . (1 CEMT). Córdoba, without specific locality, date or collector (1 MACN) . La Pampa, 35 km W de Jagüel del Monte , 14 July 1999, Maceda leg . (1 CEMT); 35 km W de Jagüel del Monte , 14 July 1999, Maceda leg . (1 IADIZA); Conhello, Estancia San Eduardo , no date or collector (1♂ IADIZA) . La Rioja, without specific locality or date, A . Breyer leg . (1 MACN). Neuquén, without specific locality,date or collector (3 MACN) . Rio Negro, Rives du Rio Negro [on the banks of Rio Negro], March–June 1897, H . de la Vaulx leg . (1 MNHN); without specific locality, date or collector [Bruch’s collection] (3 MACN); Viedma , 3–19 March 1829, d’Orbigny leg . (1♂ and 1♀ MNHN) . San Luis, Coronal Pringles, La Carolina, November 1970, H . Viana leg . (1♀ CVMD) . Tucumán, without specific locality, date or collector [G.V. Mniszech’s collection] (1 MNHN) . Without specific locality, no date, A . Breyer leg . (1 MACN); ‘ Patagones’ , no date, C . Berg leg . (1 MNHN); ‘Patagonia’,no date or collector (1 BMNH);‘Patagonia’,no date or collector (1 MNHN). BOLIVIA [dubious locality]: without specific locality, date or collector (1 BMNH).

Remarks. There are differences in the dates given for the original descriptions made by Emile Blanchard in his work ‘ Insectes de l’Amérique Méridionale ’. According to Sherborn and Woodward (1901), pages 105–222 in Blanchard’s work refer to the year 1846 as the date of publication. Many works about Trogidae’s fauna published after 1901 treated all species described by Blanchard as being from 1843 (eg Bruch 1911), 1846 (eg Arrow 1912; Blackwelder 1944; Vaurie 1962; Scholtz 1982, 1990; Zidek 2013, 2017) or 1847 ( Smith 2017; Costa-Silva and Diéguez 2020). However, Sherborn and Griffin (1934), after an examination of the original wrappings of Blanchard’s work, reorganised the text and pages with their respective year of publication, showing that all species described between pages 185 and 232 were published in 1847; therefore, this is the year that should be used (also see Evenhuis 1997; Bousquet 2016).

Figures

Figure 5. Differential morphology in Polynoncus spp.:lateral margin of pronotum a, bulbous [P.vazdemelloi] and b, rounded [P.gemmingeri]; pronotal ridges and basal tubercles of pronotum c, fused [P.furcillifer] and d, separated (black line) [P.parafurcatus]; surface of elytra e, with tubercles [P.pedestris] and f, without tubercles [P. diffluens]; g, pronotal ridge and antero-lateral tubercle connected by (white arrow) [P. patagonicus]; h, humeral callus prominent (white arrow) in P. chilensis and i, humeral callus not prominent (white arrow) in P. mirabilis. Scale bar: 1 mm.

Figure 46. Distribution map of Polynoncus mirabilis (red circles), P. parafurcatus (green triangles), and P. patagonicus (blue squares). The records with a black dot in the centre indicate the type locality of the respective species.? = dubious record.

Figure 52. Lectotype of Trox patagonicus Blanchard, 1847 (now Polynoncus patagonicus): habitus in a, dorsal and b, lateral view; c, labels. Scale bar: 1 mm.