Polynoncus diffluens ( 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 : 66-67

Polynoncus diffluens ( Vaurie, 1962)

( Figures 5f , 8 , 23 )

Trox diffluens Vaurie, 1962: 138 (original description)

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

Polynoncus diffluens : Scholtz 1986a: 362 (systematics); Scholtz 1990: 1454 (redescription); Diéguez 2008: 17 (redescription); Zidek 2013: 9 (checklist); Zidek 2017: 100 (checklist); Smith 2017: 92 (comments); Mondaca 2023: 209 (checklist from Chile)

Type specimen examined (through detailed photographs). HOLOTYPE. (♀ CASC – Figure 23 ) First label [white, aged, handwritten]: ‘LEYDA / SANTIAGO / CHILE VI-48’. Second label [white]: ‘ ♀ ’. Third label [red, Patricia Vaurie’s handwriting]: ‘TYPE / Trox / diffluens / ♀ Vaurie’. Fourth label [white with black border]: ‘ Southern Neotropical Scarabs / database # AS2617774 / Polynoncus diffluens / ( Vaurie 1962) ♀ / DET: A.B.T. SMITH 2008’. Fifth label [white, typeset]: ‘ California Academy / of Sciences / Type 8054 [handwritten] / No’. ( Figure 23c ). Type locality: ‘ Leyda’ [probably the Train Station ‘ Leyda’], located on the border between Valparaíso and Santiago, Chile.

Differential diagnosis. Polynoncus diffluens is related to Polynoncus crypticus and can easily be confused with the latter. However, P. diffluens can be separated from P. crypticus by the differences on the lateral margin of pronotum. In Polynoncus diffluens the lateral margin is smooth, while in P. crypticus it is slightly wavy with an emargination in front of the basal angle. For details of description, see Diéguez (2019, p. 90).

Geographic distribution. Polynoncus diffluens is endemic to the southern half of Chile ( Figure 8 ). Diéguez (2008) mentioned the range of distribution of P. diffluens from Santiago (Metropolitan Region) to Aisén (XI Region). In addition to the vast majority of material also studied by Diéguez (2008), we also examined material from Valparaíso. For additional records of P. diffluens in Chile, see Diéguez (2008) and Mondaca (2023).

Examined non-type material (27 specimens). CHILE: Araucanía (IX Region), Malleco, Lonquimay , February 1994, S . Castro leg . (2 CVMD). Bío-Bío (VIII Region), Ñuble, Chillan, Las Trancas , 1295 m, 36.900°S, 71.450°W, 29 December 2016, Thomas Fichet leg . (1 CVMD); Ñuble, Chillan, Las Trancas , 17 January 2005, M . Beeche leg . (1 CVMD); Ñuble, Chillan, Las Trancas , 8 January 1997, M . Beeche leg . (1 CVMD); Ñuble, Chillan, Piedras Comadres , 17 January 1992, S . Roitman leg . (1♂ CVMD); Ñubles, Los Lleuques , 4 January 2016, M . Beeche leg . (1 CVMD). Los Lagos (X Region), Calbuco , 7 km W Pargua, 25 December 2010, light trap,G . Arriagada leg .(1♂ CVMD) . Los Rios (XIV Region), Valdivia, Niebla, Llancahue , 11 December 2001, M . Galvéz leg . (1♂, 1♀ and 2 unsexed CVMD); Valdivia, Paillaco , 19 February 1999, E . Piel leg . (1 CVMD); Valdivia, Paillaco , 28November 2014,J . Reves leg . (1 CVMD); Valdivia, Panguipulli, Liquiñe , 9–15 February 1999,V .M . Diéguez leg .(1♀ CVMD); Valdivia, San José de la Mariquina, Mehuin , 23–31 January 1992, no collector (1 CVMD) . O’Higgins (VI Region), Cachapoal, Machalí , 8 February 1998,A . Ugarte leg . (2 CVMD); Rancagua , 15 December 1946, no collector (1 MNNC) . Santiago (Metropolitan Region), Melipilla, Fundo San Luis Pallocabe , 300 m, 10–15 December 2001, light trap,V .M .Diéguez leg .(1 CVMD; 1♂ CEMT); Melipilla, Villa de San Gerónimo de La Sierra de Alhué , January 1947, no collector (5 MNNC) . Valparaíso (V Region), Marga Marga, Olmué , January 1950, no collector (1 MNNC) .

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 8. Distribution map of Polynoncus aeger (red circles), P. aricensis (green triangles), and P. diffluens (blue squares) in South America. The records with a black dot in the centre indicate the type locality of the respective species.? = dubious record.

Figure 23. Holotype of Trox diffluens Vaurie, 1962 (now Polynoncus diffluens): habitus in a, dorsal and b, lateral view; c, labels. Photos by Rachael Diaz-Bastin (CASC).