Polynoncus bifurcatus ( Vaurie, 1962 )

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 : 41-45

Polynoncus bifurcatus ( Vaurie, 1962)

( Figures 10 , 12 )

Trox bifurcatus Vaurie, 1962: 129 (original description)

Trox (Polynoncus) bifurcatus : Scholtz 1982: 15 (catalogue)

Polynoncus bifurcatus : Scholtz 1986a: 362 (systematics); Pittino 1987: 393 (redescription); Scholtz 1990: 1441 (redescription); Gómez 2008: 517 (key to Argentinean species); Zidek 2013: 7 (checklist); Correa et al. 2013, p. 239 –240 (records from centre of Brazil); Zidek 2017: 98 (checklist); Costa-Silva and Diéguez 2020: 271 (records from Argentina)

Polynoncus furcifer Pittino, 1987: 394 (original description); Scholtz 1990: 1441 (synonym); Zidek 2013: 10 (checklist); Zidek 2017: 101 (checklist)

Type specimens examined. HOLOTYPE. (♂ MFNB – Figure 12 ) First label [old, green, typeset]: ‘O. Bolivien / Prov. Sara / J. Steinbach S.V’. Second label [white, Patricia Vaurie’s handwriting]: ‘ Trox / bifurcatus / Vaurie / Type ♂ ’. Third label [red with black frame]: ‘ Holotypus / Nr’. Fourth label [white with black frame, Riccardo Pittino’s handwriting]: Polynoncus / bifurcatus (Vaurie) / Det. Pittino 1988” ( Figure 12d ). Type locality: ‘Prov. [Province] Sara’ (eastern Bolivia); the type specimen was collected by Joseph Steinbach (1875–1930), a German naturalist who lived and collected in Bolivia during the first half of the twentieth century ( Anonymous 1916; Llave et al. 2015).

PARATYPES (1 ♂ and 3 unsexed MFNB, all with the same information) . First label [old, green, typeset]: ‘O. Bolivien / Prov. Sara / J. Steinbach S.V’. Second label [white, Patricia Vaurie’s handwriting]: ‘ Trox / bifurcatus / Vaurie / PARATYPE’. Third label [red with black frame]: ‘ Paratypus / Nr’.

Type specimens of Polynoncus furcifer Pittino, 1987 (not examined). HOLOTYPE (♂ HNHM). Type locality: ‘Asunción’ ( Paraguay), collected by Hungarian biologist János Dániel Anisits (1856–1911) in September and October 1904.

PARATYPES EXAMINED (1 ♂ [ Figure 13 ] and 1 ♀ MNHN; 3 ♂ and 1 ♀ RPMI [through detailed photographs]). First label [white, aged, typeset]: ‘ Paraguay Central / P . Germain / 1885’. Second label [green, typeset]: ‘ Museum Paris / ex Coll . / R. Oberthur’. Third label [white, Patricia Vaurie’s handwriting]: ‘ Trox / bifurcatus / Vaurie / Vaurie ‘61 ’. Fourth label [white, handwritten]: ‘ ♀ ’. Fifth label [red, Riccardo Pittino’s handwriting]: ‘ Polynoncus ♀ / furcifer n. sp. / Det. R. Pittino 1987 ’. Sixth label [red, typeset]: ‘PARATYPUS’. Seventh label [white, printed]: ‘MNHN / EC9640’ (1 ♀ MNHN) . First label [white, aged, typeset]: ‘ Paraguay Central / P . Germain / 1885’. Second label [green, typeset]: ‘ Museum Paris / ex Coll . / R. Oberthur’. Third label [white, Patricia Vaurie’s handwriting]: ‘ Trox / bifurcatus / Vau . / Vaurie ‘61’. Fourth label [red, typeset]: ‘PARATYPE’. Fifth label [red, Riccardo Pittino’s handwriting]: ‘ Polynoncus ♂ / furcifer n. sp. / Det. R. Pittino 1987 ’. Sixth label [white, printed]: ‘MNHN / EC9639’ (1 ♂ MNHN – Figure 13e ) . First label [white, aged, typeset]: ‘ Brésil / Prov . Matto-Grosso / P. Germain / 1886’. Second label [green, typeset]: ‘ Museum Paris / ex Coll . / R. Oberthur’. Third label [white, Patricia Vaurie’s handwriting]: ‘ Trox / bifurcatus / Vau . / Vaurie ‘61’. Fourth label [red, typeset]: ‘PARATYPUS’. Fifth label [red, Riccardo Pittino’s handwriting]: ‘ Polynoncus ♂ / furcifer n. sp. / Det. R. Pittino 1987 ’ (1 ♂ RPMI) . First label [white, typeset]: ‘ Paraguay / Anisits’ . Second label [white, typeset]: ‘ Asuncion’ . Third label [red, typeset]: ‘PARATYPUS’. Fourth label [red, Riccardo Pittino’s handwriting]: ‘ Polynoncus ♂ / furcifer n. sp. / Det. R. Pittino 1987 ’. Fifth label [white, handwritten]: ‘COLL. R. PITTINO’ (1 ♂ RPMI) . First label [white, typeset]: ‘ Asunción / Paraguay’ . Second label [white, typeset]: ‘EX COLL. / WINKLER, WIEN’. Third label [red, typeset]: ‘PARATYPUS’. Fourth label [red, Riccardo Pittino’s handwriting]: ‘ Polynoncus ♀ / furcifer n. sp. / Det. R. Pittino 1987 ’ (1 ♀ and 1 ♂ RPMI) .

Differential diagnosis. Polynoncus bifurcatus is most similar to Polynoncus parafurcatus but can be readily distinguished from the latter by the presence of small yellow setae in the surface of the elytral tubercles. Polynoncus parafurcatus has black setae on the tubercles. This characteristic is easier to see with good illumination and a stereomicroscope with 128× magnification. The male genitalia of the two species are distinctive. Polynoncus bifurcatus has a foliaceous and undulating lateral dilatation in the right side of the medial lobe ( Figure 12c ), which is absent in P. parafurcatus or indicated with a projection pointed laterally (see figs. 58 and 64 in Pittino 1987, p. 387). For more details of the description and aedeagus drawings, see Vaurie (1962, p. 129), Pittino (1987, p. 387) and Scholtz (1990, p. 1441).

Geographic distribution. Polynoncus bifurcatus is distributed widely in central South America, mainly in the Chaco region. It is recorded from Bolivia, Brazil, Paraguay and Argentina ( Figure 10 ).

Examined non-type material (134 specimens). ARGENTINA: Catamarca, without specific locality, 4 December 2003,sheep carcass,no collector (1 IADIZA); without specific locality, 4 December 2003,sheep carcass,no collector (1 IFML) . Chaco, Capitán Solari , 26.812°S, 59.555° W, 10 September 2016, pitfall trap, wet chaco, C . Guerra-A leg. (1♂ and 7 unsexed CEMT) ; Resistencia, no date, Mello [Bosq’s collection] leg. (1 MLPA) ; Resistencia , November 1945, A . Martinez leg . (2♂ SAMC); Río Muerto , 26.125°S, 61.677°W, 31 October 2016, pitfall trap, dry chaco,C . Guerra-A leg. (1♂ IEXA) ; Río Muerto , 26.125°S, 61.677°W, 31 October 2016, pitfall trap, dry chaco, C . Guerra-A leg. (1♂ and 1 unsexed CERPE) ; Río Muerto , 26.125°S, 61.677°W, 31 October 2016, pitfall trap, dry chaco, C . Guerra-A leg. (1♂, 2♀ and 14 unsexed CEMT) ; without specific locality, 30 October 1986, no collector (3♂ SAMC); without specific locality, date or collector (1 MACN) . Entre Rios, Concordia , Salto Grande Bridge, 1979, A . Martinez leg . (1♀ SAMC) . Formosa, Formosa, January 1905, no collector [Bruch’s collection] (1 MACN); Formosa, March 1905, no collector [Bruch’s collection] (1 MACN); Laguna Blanca , April 1948, I . Morel leg . (1 IFML). Jujuy,without specific locality,date or collector [Bruch’s collection] (1 MACN);without specific locality, date or collector [Richter’s collection] (1 MLPA). Misiones, without specific locality, date or collector [Bruch’s collection] (1 MACN). Salta, Capiazutí , November 1953, M . Viana leg . (1 CVMD); Coronel Moldês , December 1958, A . Martinez leg . (1♂ MZSP) . Santiago del Estero, Pampa de los Guanacos , 25.751°S, 61.714°W, 31 October 2016, C . Guerra-A leg. (4 CEMT). Tucumán,without specific locality,date or collector (1 MACN); without specific locality, November–December 1944, R . Golbach leg . (1 IFML); without specific locality, November– December 1944,R . Golbach leg .(5 IFML). BOLIVIA: Beni, La Santísima Trinidad, 3 January 1949, Kusche leg . (1 CVMD). Santa Cruz de la Sierra, Sara , 450 m, October 1909,J . Steinbach leg.(1♂ SAMC) ; Sara, Cuatro Ojos , no date, J . Steinbach leg. (1♂ SAMC) ; Sara , February 1958, F . Monrós leg . (1 IFML). Without specific locality, date or collector (1 MACN) . BRAZIL: Mato Grosso do Sul, Aquidauana , 20.448°S, 49.644°W, 15 October 2011, pitfall trap in carcass,C .M .A.Correa leg . (1♂, 1♀ and 1 unsexed CEMT); Aquidauana, Piraputanga , 20.466°S, 55.533°W, 6 October 2010, pitfall trap with banana, J .L .N. Oliveira leg . (2 CEMT); Corguinho, Quinta do Sol , 19.832°S, 54.829°W, February 2011, human faeces, L .O . Bavutti leg . (2♂ CEMT); Corumbá, Alto Paraguay , no date or collector [Richter’s collection] leg. (1♀ MLPA) ; Corumbá, Pantanal do Miranda , January 2000, J .N .C. Louzada leg . (1 CEMT); Corumbá, Pantanal Studies Base, Federal University of Mato Grosso do Sul, 6 October 2011, M .B . Pessoa leg . (5 CVMD); Corumbá, Passo do Lontra , February 1996, Louzada and Vaz-de-Mello leg . (1♂ and 6♀ CEMT); Corumbá, Passo do Lontra , February 1996, Louzada and Vaz-de-Mello leg . (1♀ CVMD); Corumbá, São Bento Farm , 19.498°S, 57.028°W, June 1999, L . Vieira leg . (1 CEMT); Corumbá, São Judas Farm ( Rio Vermelho ), 19.611°S, 56.963°W, March 1999,L . Vieira leg . (1♂ CEMT); Corumbá, São Judas Farm ( Rio Vermelho ), 19.611°S, 56.963°W, August 1999, L . Vieira leg . (1 CEMT); Corumbá, São Judas Farm ( Rio Vermelho ), 19.611°S, 56.963°W, June 1999, L . Vieira leg . (1 CEMT); Porto Murtinho, ConceiÇão Farm , 21.686°S, 57.770°W, March 2011, human faeces, L .O . Bavutti leg . (1♂ and 1♀ CEMT); Porto Murtinho , January 1930, R . Spitz leg . (1♀ MZSP); Porto Murtinho, 1929, R . Spitz leg . (1♀ MZSP) . Mato Grosso, Figueirópolis d’ Oeste, Monte Fusco Farm, 308 m, 15.529°S, 58.636°W, 11–13 January 2013, pitfall with human and pig dung as bait, R .J . Silva leg . (1♂ CEMT) . Paraná, Londrina, Mata dos Godoy State Park , 610 m, 23.433°S, 53.833°W, 24 April 2016, malaise, R . Barros leg . (1♀ CEMT) . PARAGUAY: Boquerón, Loma Plata , 20–30 January 1995,P . Gerlach leg . (1♂ CVMD); Loma Plata , January 1994, P . Gerlach leg . (1♂ and 1♀ CEMT); Loma Plata , 20–30 January 1994, P . Gerlach leg . (5 CVMD); Alto Paraguay, Puerto Voluntad , 20.700°S, 57.983°W, 5–6 September 1997, B . Garcete leg . (2♂ and 1♀ CEMT); Cruce Los Pioneros , 7–28 January 1996, P . Gerlach leg . (1♂ and 7 unsexed CVMD); Loma Plata , 8–29 January 1994, P . Gerlach leg . (2♀ CVMD) . Central, without specific locality, 1889, P . Germain leg . (1♂ and 2♀ MNHN) . Cordillera, Emboscada , February 1976, M . Viana leg . (1 total, 1♂, ♀ CVMD) . Itapuá, Trinidad , October 1913, no collector (1 MLPA) . Paraguarí, Compañía Naranjo, 16 July 2001, no collector (2♀ CVMD); Compañía Naranjo , 27 September 1999, Carlos Aguilar J . leg . (2♂ and 6 unsexed CVMD); Compañía Naranjo , 28 August 2001, Carlos Aguilar J . leg . (1♂ CVMD); Compañía Naranjo , 6–10 November 2001, no collector (1♂ CVMD) . Without specific locality, December 1936, Le Moult leg . (1♂ SAMC); without specific locality, date or collector (1 MLPA) .

Remarks. Pittino (1987) described Polynoncus furcifer Pittino, 1987 from a small number of specimens collected from Paraguay and Brazil. Despite having identical external morphology to P. bifurcatus, Pittino at the time considered differences on the ventral piece of the median lobe on male genitalia to be geographically distinctive and a reliable character to distinguish between P. furcifer (Paraguay-Brazil) from P. bifurcatus ( Bolivia). However, Scholtz (1990), during his revision of South American fauna of Trogidae , and after seeing additional material, found the differences listed by Pittino to be unreliable for distinguishing the two species and synonymised P. furcifer with P. bifurcatus .

After studying a large series of specimens (> 100) identified as P. bifurcatus housed in several collections, we found the variation of the ventral piece of the median lobe, as cited by Pittino (1987), is not specific and can be found within a single series of specimens across populations from Argentina, Bolivia, Brazil and Paraguay. Thus, we agree with Scholtz (1990) and maintain P. furcifer as a junior synonym of P. bifurcatus .

Figures

Figure 10. Distribution map of Polynoncus argentinus (red circles), P. bifurcatus (green triangles), and P. chilensis (blue squares) in South America. The records with a black dot in the centre indicate the type locality of the respective species.

Figure 12. Holotype of Trox bifurcatus Vaurie, 1962 (now Polynoncus bifurcatus): habitus in a, dorsal and b, lateral view; c, male genitalia in dorsal view; d, labels.

Figure 13. Paratype of Polynoncus furcifer Pittino, 1987: habitus in a, dorsal and b, lateral view; male genitalia in c, dorsal and d, lateral view; e, labels. Photos by Christophe Rivier (MNHN).