Polynoncus hemisphaericus ( Burmeister, 1876 )

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 : 98-101

Polynoncus hemisphaericus ( Burmeister, 1876)

( Figures 4a, 4f , 37 , 40–41 )

Trox hemisphaericus Burmeister, 1876: 253 (original description); Berg 1884: 145 (taxonomic notes); Preudhomme de Borre 1886: 73 (checklist); Bruch 1911: 193 (checklist); Arrow 1912: 56 (catalogue); Blackwelder 1944: 218 (checklist – as ‘ hemisphaerica ’); Vaurie 1962: 142 (redescription)

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

Polynoncus hemisphaericus : Scholtz 1986a: 362 (systematics); Scholtz 1990: 1424 (redescription); Diéguez 2008: 18 (redescription); Gómez 2008: 515 (key to Argentinean species); Bachmann et al. 2010: 54 (catalogue of types housed in MACN); Zidek 2013: 11 (checklist); Zidek 2017: 102 (checklist); Smith 2017 (distribution and comments); Costa-Silva and Diéguez 2020: 272 (records from Argentina); Mondaca 2023: 210 (checklist from Chile)

Trox globulatus Fairmaire, 1884: 490 (original description); Berg 1884: 145 (synonym); Preudhomme de Borre 1886: 72 (catalogue); Bruch 1911: 193 (checklist – as synonym of T. hemisphaericus ); Arrow 1912: 56 (catalogue, as junior synonym of T. hemisphaericus ); Vaurie 1962: 142 (as synonym); Scholtz 1982: 16 (catalogue – as synonym); Scholtz 1990: 1224 (as synonym); Zidek 2013: 10 (checklist – as synonym); Zidek 2017: 101 (checklist – as synonym); Smith 2017: 95 (comments – as synonym); Mondaca 2023: 210 (checklist – as synonym)

Type specimens examined. LECTOTYPE HERE DESIGNATED. ( MACN – Figure 40 ) First label [red with black border, Axel Bachmann’s handwriting]: “ Trox / hemisphaericus / Burmeister / 1876 / Syntypus [vertical]. Second label [red, typeset]: ‘LECTOTYPE’. Thi..rd label [red, Vinícius Costa-Silva’s handwriting]: ‘ Trox hemisphaericus / Burmeister 1876 / des. V. Costa-Silva’. Fourth label [white with black border, typeset]: ‘MACN-En / 1118’ ( Figure 40c ). Type locality: Puerto Santa Cruz, Province of Santa Cruz, Argentina. Note. None of the specimens in the type series carry any locality labels. Burmeister (1876) stated in his description that the type series was collected by Carlos Berg along the Santa Cruz River. Carlos Berg (or Friedrich Wilhelm Karl Berg) was a member of an expedition team to Patagonia in 1874 ( Berg 1875; Gallardo 1902). According to Berg (1875, p. 367), on 8 October 1874, the expedition anchored at the mouth of the Santa Cruz River because of its intense flow. Once the flow of the river decreased, the expedition traveled upriver for about 11 English miles (~ 17 km) to Puerto Santa Cruz (50°01 ʹ S, 68°31 ʹ W), where the expedition team spent two days collecting and studying the local fauna and flora. Puerto Santa Cruz is more likely to be the type locality of Trox hemisphaericus .

PARALECTOTYPES (8 MACN, all with the same data label) . First label [red with black border, Axel Bachmann’s handwriting]: “ Trox / hemisphaericus / Burmeister / 1876 / Syntypus [vertical]. Second label [red, typeset]: ‘PARALECTOTYPE’. Third label [red, Vinícius Costa-Silva’s handwriting]: ‘ Trox hemisphaericus / Burmeister 1876 / des. V. Costa-Silva’.

Type specimen examined of Trox globulatus Fairmaire, 1884 . LECTOTYPE HERE DESIGNATED. ( MNHN – Figure 41 ) First label [white, aged, typeset]: ‘MUSEUM PARIS / SANTA CRUZ / PATAGONIE / LEBRUN 1884’. Second label [round, handwritten]: ‘2551 / 83’. Third label [white, aged, León Fairmaire’s handwriting]: ‘ Trox / globulatus / Fairm’. Fourth label [red with black frame, Vinícius Costa-Silva’s handwriting]: ‘ LECTOTYPE / Trox globulatus / Fairmaire, 1883 / des. V. Costa-Silva 2022’ ( Figure 41c ). Type locality: ‘Patagonie, Santa Cruz’. The number 2551 (round label) in Lebrun’s catalogue refers to a specimen collected in Punta Arenas, XII Region of Magallanes ( Chile) by the French taxidermist Édouard A. Lebrun (1852–1904), in 1883, during his expedition across the Straits of Magellan. Note. There are four more specimens with the same label information as the lectotype housed at MNHN, but without any indication (ie determination labels) that they were studied by L. Fairmaire. As recommended by the Code (ICZN 1999), these specimens were not included as paralectotypes.

Differential diagnosis. Polynoncus hemisphaericus can be easily recognised by its convex body shape. Furthermore, this species is unique among the wingless species in that it bears on the middle and hind tibia long black setae. It also resembles P. pampeanus , but can be differentiated from the latter by the presence of a basal tubercle of pronotum distinctly visible, which is obsolete in P. pampeanus . For details of description, see Vaurie (1962, p. 142) and Scholtz (1990, p. 1424).

Geographic distribution. Polynoncus hemisphaericus is recorded in the arid zones of Argentine Patagonia and southern Chile (Magallanes and Chilean Antarctic Territory) ( Figure 37 ).

Smith (2017) mentioned that records of the P. hemisphaericus from Buenos Aires, Neuquén, and Río Negro are doubtful and need confirmation. Our study confirmed, based on additional examined specimens, the records for these localities. Furthermore, after the study of several specimens, we expand the geographical known distribution of this species to the north (Mendoza), when compared with earlier authors (ie Vaurie 1962; Scholtz 1990; Costa-Silva and Diéguez 2020).

Examined non-type material (74 specimens). ARGENTINA: Buenos Aires, Carmen de Patagones , no date or collector (1 MACN) . Chubut, Cerro Negro , 15 February 1927, C . Bruch leg . (1 MACN); Estancia La Escondida , 24 April 1941, Maldonado leg . (1 MLPA); Gaiman, Bryn Gwyn , April–May 2011, trampa c/ pollo [pitfall trap with chicken as bait], D . Rojas Lanus leg . (1 CVMD); Golfe St . Georges, Coli-Huapi , 1903, A . Tournoüer leg . (1 MNHN); Trelew , 20 March 2010, D . Rojas Lanus leg . (1 CVMD); Trelew , 20 November 2005, D . Rojas Lanus leg . (1 CVMD); Trelew , 28 January 2002, D . Rojas Lanus leg . (1 CVMD); Valle del Lago Blanco , 1903, no collector (2 BMNH); without specific data, February 1897, C . Bruch leg . (1 MACN); without specific locality, 30 April 1977, J . Solervicens leg . (1 CVMD); without specific locality, date or collector (1 BMNH). Mendoza, Laguna del Diamante , 2319 m, 20 November–17 December 2012, pitfall trap with human feaces, G . Arriágada leg . (1♀ CEMT); Laguna del Diamante , 2319 m, 20 November–17 December 2012, pitfall trap with human faeces, G . Arriagada leg . (1 CVMD); Malargüe, El Nevado , 7 km E . Ruta 186, 2198 m, 35.624°S, 68.601°W, 21 February 2006, R . Carrara leg . (10 IADIZA); Malargüe, El Nevado , 7 km E . Ruta 186, 2198 m, 35.624°S, 68.601°W, 21 February 2006, R . Carrara leg . (2 CEMT); Malargüe, Provincial Reserve La Payunia Manchón, Molle Camino Payún , 2267 m, 36.347°S, 69.257°W, 29 January 2010, R . Carrara, E . Scheibler, F. Campón leg . (1 IADIZA); San Carlos , 14 km E Refugio Alvarado, 1760 m, 2 November 2015, G . Flores leg . (1 IADIZA); San Carlos, Laguna del Diamante , 1800 m, 31 January 2016,F . Aballay and F . Jofré leg . (1 IADIZA); San Rafael, Volcón Diamante , 2233 m, 26 December 2015 – 10 January 2016, S . Roig and G . Debandi leg. (1 CEMT). Neuquén, without specific locality, 1907, Dr Adolf Lendl leg. (1 MNHN); without specific data (3 MACN). Río Negro, San Carlos de Bariloche, Estância San Ramon , 27 June 1966, no collector (1 BMNH); without specific locality (11 MACN); without specific locality, 4 March 1909, C . Bruch leg . (1 MACN); without specific locality, C . Bruch leg . (1 MLPA); without specific locality, C . Bruch leg . (3 MACN). Santa Cruz, Patagônia National Park (1 MACN); Río Gallegos , 1937, H . de Miller leg . (1 MLPA). CHILE: Magallanes (XII Region), Lago Sarmiento, National Park Torres del Paine , 20 January 1950 (2 MNNC); Laguna Amarga , 8 November 1961, Cekalovic leg . (2 MNNC); Patagonie, Punta Arenas , 1889, M .E . Lebrun leg . (8 MNHN); Río de las Chinas , 2 November 1952, T . Cekalovic leg . (1♂ CVMD); Río Las Chinas, 2 November 1952 (1 MNNC); Ultima Esperanza, Cerro Guido , 7 January 2010, en oveja [sheep], Douglas Jackson leg . (4 CVMD); Ultima Esperanza, Cerro Guido , 7 January 2010, en oveja [sheep], Douglas Jackson leg . (1♂ CEMT); without specific data, 20 January 1950 (1 CVMD) .

Figures

Figure 4. Differential morphology in Polynoncus spp.: a, without humeral callus [P. hemisphaericus]; b, with humeral callus [P. longitarsis]. Apex of mesotibia c, with tooth [P. peruanus] and d, without tooth (white arrow) [P. crypticus]. Posterior margin of clypeus e, emarginate [P. bullatus] and f, truncate (white arrow) [P. hemisphaericus]; pronotal ridges of pronotum in g, Polynoncus argentinus and h, Polynoncus pseudogemmifer sp. n. (paratype). Scale bar: 1 mm.

Figure 37. Distribution map of Polynoncus gemmingeri (red circles), P. gordoni (green triangles), and P. hemisphaericus (blue squares) in South America. The records with a black dot in the centre indicate the type locality of the respective species.

Figure 40. Lectotype of Trox hemisphaericus Burmeister, 1876 (now Polynoncus hemisphaericus), here designated: habitus in a, dorsal and b, lateral view; c, labels. Photos by Luis Compagnucci (MACN).

Figure 41. Lectotype of Trox globulatus Fairmaire, 1884 (= Polynoncus hemisphaericus), here designated: habitus in a, dorsal and b, lateral view; c, labels. Scale bar: 1 mm.