Scybalocanthon pygidialis ( Schmidt, 1922 )

Silva, Fernando A. B. & Valois, Marcely, 2019, A taxonomic revision of the genus Scybalocanthon Martínez, 1948 (Coleoptera Scarabaeidae: Scarabaeinae: Deltochilini), Zootaxa 4629 (3), pp. 301-341 : 331-333

Scybalocanthon pygidialis ( Schmidt, 1922)

( Figs. 2B , 4T , 5S , 6D )

Canthon pygidialis Schmidt, 1922: 65 , 79, 90 (original description and remarks); Balthasar 1939: 192 (description); Blackwelder 1944: 201 (checklist); Krajcik 2006: 30 (catalog); Krajcik 2012: 64 (catalog); Vaz-de-Mello & Cupello 2018: 63 (data of type specimens), 64 (figures 85-88).

Scybalocanthon pygidialis: Pereira & Martínez 1956: 114 , 119 (catalog and identification key); Vulcano & Pereira 1964: 639 (catalog); Vulcano & Pereira 1967: 554 (distribution, identification key); Halffter & Martínez 1977: 67 (species list); Medina et al. 2003: 49 (fig. 119).

Scybalocanthon pygidiale : Vaz-de-Mello 2000: 194 (checklist).

Diagnosis. Specimens of S. pygidialis are readily distinguishable from all the remaining species in the genus by the pronotum with longitudinal dark band on midline anteriorly ( Fig. 2B ); elytra brown or dark yellow, with black spot almost inconspicuous on the margin ( Fig. 2B ); eighth elytral stria with thin carina at the anterior portion; parameres strongly asymmetrical ( Fig. 4T ); endophallus with bristles right beside the FLP sclerite ( Fig. 5S ); and additional sclerite ( AS) absent ( Fig. 5S ).

Description. Body. Oval-elongate. Surface opaque, completely microgranulate. Color. Most of pronotum, lateral portion of hypomera, metaepisternae, metaventrite, abdominal ventrites, pygidium, middle of femora, and tibiae yellow or light brown. Head, elytra, prosternum, mesoventrite, mesoepisternae, trochanters, and proximal and distal portions of femora dark brown or black. Length. 8.0– 9.2 mm. Thorax. Pronotum with brown vertical spot on the anterocentral portion ( Fig. 2B ), spot not touching the posterior margin of pronotum. Anterior angles of pronotum approximately 85°. Lateral margin regularly curved outward, not forming an angle at the middle portion. Elytra. Striae thin and shiny, punctures inconspicuous. Eighth stria with a thin carina at the anterior portion ( Fig. 3D ). Aedeagus. Parameres strongly asymmetrical ( Fig. 4T ). Dorsal margin of right paramere curved inward, apex obliquely truncate. Ventral margin of right paramere substraight, with short and rounded excavation at the basal portion. Dorsal margin of left paramere curved inward from the basal to medial portions, apical portion with pointed projection. Ventral margin of left paramere substraight, with short and bilobate excavation at the basal portion, apical portion pointed. SRP circular, with substraight handle-shaped extension ( Fig. 5S ). FLP short, comma shaped, with three sets of bristles right beside it ( Fig. 5S ); or with two sets of bristles and a set of microbristles right beside it ( Fig. 5T ). A+SA with two superposed and elongate sclerites ( Fig. 5 S-T).

Type material. Canthon pygidialis Schmidt , lectotype ♂ (here designated; SMTD): “Amazonas” // “ Coll. C. Felsch / Kauf 20 / 1918” // “ Canthon / pygidialis / n. sp. a. Schmidt ” // “ LECTOTYPE ♂ / Canthon / pygidialis / Schmidt / des. F. Z. Vaz-de-Mello” . Paralectotypes 1♂ and 4♀ ( SMTD): “ Surinam ” // “ Coll. C. Felsche / Kauf 20 / 1918” // “ PARALECTOTYPE / Canthon ♂ or ♀ / pygidialis / Schmidt / des. F. Z. Vaz-de-Mello”. Paralectotype ♀ ( SMTD): “ Coll. C. Felsche / Kauf 20 / 1918” // “ PARALECTOTYPE / Canthon ♀ / pygidialis / Schmidt / des. F. Z. Vaz-de-Mello”. Paralectotype ♂ ( NHRS): “ Surinam ” // “pygidialis” // “32 / 56” // “3056 / E92 +” “PARA- LECTOTYPE ♂ / Canthon / pygidialis Schm. / des. F. Z. Vaz-de-Mello” . Paralectotype ♀ ( NHRS): “ Surinam ” // “ pygidiali ” // “3054 / E92+” // “ Scybalocanthon / pygidialis / Schm / P. Pereira Det. 60 ” // “ PARALECTOTYPE ♀ / Canthon / pygidialis Schm. / des. F. Z. Vaz-de-Mello ” . Paralectotype ♀ ( NHRS): “ Surinam ” // “ pygidialis, A. Schm. ” // “ Scybalocanthon / pygidialis / ( Schm ) / P. Pereira det. 60” // “3055 / E92 +” // “ PARALECTOTYPE ♀ / Canthon / pygidialis Schm. / des. F. Z. Vaz-de-Mello” . Paralectotype ♀ ( MNHU): “ S. Amerika / Surinam / Berlik Paramaribo / C. Heller S. V.” // “ rufulus ? ” // “ Canthon / pygidialis / n.sp. a. Schmidt ” // “117088” // “PARALEC- TOTYPE / Canthon ♀ / pygidialis / Schmidt / des. F. Z. Vaz-de-Mello ”. Paralectotype ♀ ( MNHU): “columbi?” / “Coll. L. W. SchaufuB” // “=117089” // “117089” // “ PARALECTOTYPE / Canthon / pygidialis / Schmidt / des. F. Z. Vaz-de-Mello ” .

Non-type material [ 86 males, 55 females]: BRAZIL: AMAZONAS: 90 km N of Manaus (60°1’34’’W, 3°6’26’’ S), xi.1997, E. Andresen— 15♂ 9♀ ( CEMT) ; 90 km N of Manaus (60°1’34’’W, 3°6’26’’ S), X–XI.1996, E. Andresen— 2♂ 1♀ ( CEMT) ; Manaus, Reserva Adolpho Ducke (sede) (59°58’32”W, 02°55’49”S), 3.v.2013, F.Z. Vaz-de-Mello— 5♂ 4♀ ( CEMT) ; Manaus, Reserva Adolpho Ducke (sede) (59°55’40”W, 2°57’42”S), 16.v.2012, J. Bonanomi— 11♂ 5♀ ( CEMT) ; RORAIMA: Pacaraima , primary forest, ix. 1996, 900 m, Ribeiro & Vaz-de-Mello— 1♀ ( CEMT) ; AMAPÁ: Serra do Navio, Cava Urucum-Amapari (51°52’53”W, 00°53’06”S), ix.2000, R. Ribon— 2♂ 2♀ ( CEMT) . VENEZUELA: BOLÍVAR, 85 km S El Dorado (6°7’58’’N, 61°25’34’’W), 23–25.viii.1983, B.D. Gill— 2♂ ( CMNC) ; km 40 Santa Elena, Icabarú Road , 1000 m (7°26’20’’N, 61°33’30’’W), 4-6.viii.1986, B.D. Gill— 1♂ ( CMNC) ; “km 88”, 8 km S San Isidro (6°8’58’’N, 61°25’55’’W), 25.vi–11.vii.1987, S. & J. Peck, lowland rainforest, flight interception trap— 2♀ ( CMNC) ; Quebrada de Jaspe (4°54’30’’N, 61°5’30’’W), 19–20.vii.1986, B. Gill— 1♂ ( CMNC) . FRENCH GUIANA: Maripa , 8.xi.1969, G. Halffter— 1♂ ( CEMT) ; 18.4 km SSE Roura , 240 m (4°36’38’’N, 52°13’25’’W), 22–24.v.1997, J. Ashe & R. Brooks, flight interception trap (1997-24)— 1♂ ( CMNC) ; 18.4 km SSE Roura , 240 m (4°36’38’’N, 52°13’25’’W), 25–29.v.1997, J. Ashe & R. Brooks, flight interception trap (1997-81)— 1♂ ( CMNC) ; 18.4 km SSE Roura , 240 m (4°36’38’’N, 52°13’25’’W), 29.v–10.vi.1997, J. Ashe & R. Brooks, flight interception trap (1997-180)— 1♂ 2♀ ( CMNC) ; 27.4 km SSE Roura , 280 m (4°44’20’’N, 52°13’25’’W), 23–24.v.1997, J. Ashe & R. Brooks, flight interception trap (1997-22)— 1♂ ( CMNC) ; 27.4 km SSE Roura , 280 m (4°44’20’’N, 52°13’25’’W), 25–29.v.1997, J. Ashe & R. Brooks, flight interception trap (1997-79)— 1♂ 1♀ ( CMNC) ; 27.4 km SSE Roura , 280 m (4°44’20’’N, 52°13’25’’W), 10.vi.1997, J. Ashe & R. Brooks, flight interception trap (1997-177)— 6♂ 6♀ ( CMNC, MZUFPA) ; 39.4 km SSE Roura , 270 m (4°32’43’’N, 52°8’26’’W), 29.v–10.vi.1997, J. Ashe & R. Brooks, flight interception trap (1997-172)— 2♂ ( CMNC) ; 41.5 km SSW Matoury , 50 m (4°37’22’’N, 52°22’35’’W), 29.v–9.vi.1997, J. Ashe & R. Brooks, flight interception trap (1997-170)— 1♂ 3♀ ( CMNC) ; 8.4 km SSE, Roura , 200 m (4°40’41’’N, 52°13’25’’W), 25–29.v.1997, J. Ashe & R. Brooks, flight interception trap (1997-88)— 2♂ 1♀ ( CMNC) ; 8.4 km SSE, Roura , 200 m (4°40’41’’N, 52°13’25’’W), 29.v–10.vi.1997, J. Ashe & R. Brooks, flight interception trap (1997-182)— 9♂ 7♀ ( CMNC, MZUFPA) ; D-5, 4 km SE Tonnégrand junction (4°52’10’’N, 52°31’55’’W), 25-27.viii.1995, J.E. Wappes— 1♂ ( CMNC) ; Les Eaux Claires , 7 km N Saül, 220 m (3°39’46’’N, 53°13’19’’W), 31.v–3.vi.1997, J. Ashe & R. Brooks, pitfall trap, human dung (1997-126)— 2♀ ( CMNC) ; Mont Galbao, Saül , 740 m (3°37’18’’N, 53°16’42’’W), 5–7.vi.1997, J. Ashe & R. Brooks, flight interception trap (1997-153)— 1♂ ( CMNC) ; Mont La Fumée, 3 km NW Les Eaux Claires, 7 km N Saül , 490 m (3°39’46’’N, 53°13’19’’W), 1–8.vi.1997, J. Ashe & R. Brooks, flight interception trap (1997-162)— 1♂ 1♀ ( CMNC) ; Mont La Fumée, 3 km NW Les Eaux Claires, 7 km N Saül , 490 m (3°39’46’’N, 53°13’19’’W), 1–8.vi.1997, J. Ashe & R. Brooks, human dung trap (1997-163)— 1♂ ( CMNC) ; Rivière Lunier , 1899, F. Geay— 1♂ 1♀ ( CMNC) ; CAYENNE: Nouragues (52°40W, 4°5’S), iii.1997, F. Feer— 4♂ ( CEMT) ; Paracou field station, x.2003, F. Feer— 2♂ 2♀ ( CEMT) ; Sain Eugène, Barrage de Petit Saut (53°4’W, 4°5’S), xii.1998, F. Feer— 2♂ 2♀ ( CEMT) ; Saint Georges de I’ Oy- apok (51°48’W, 3°54’S), v.2014, F. Feer— 1♂ ( CEMT) . SURINAME: BROKOPONDO, Brownsberg Natuurpark [site 2], 440 m (4°56’55’’N, 55°10’53’’W), 25.vi.1999, Z. Falin, flight interception trap ( FIT121 ) — 1♂ ( CMNC) ; COMMEWIJNE, Akintosoel, CELOS camp, road to Redi Doli , 50 m (5°16’17’’N, 54°55’15’’W), 2.vii.1999, Z. Falin, dung trap— 1♂ ( CMNC) ; Akintosoel, CELOS camp, road to Redi Doli , 50 m (5°16’17’’N, 54°55’15’’W), 3.vii.1999, Z. Falin— 1♀ ( CMNC) ; MAROWIJNE, Nassau Mountains (4°48’N, 54°36’W), 5.iii.1949, D.C. Gei- jskes— 1♂ ( CMNC) ; Palumeu , 160 m (3°20’56’’N, 55°26’18’’W), 8.vii.1999, Z. Falin, flight interception trap— 1♂ 1♀ ( CMNC) ; Palumeu , 160 m (3°20’56’’N, 55°26’18’’W), 9.vii.1999, Z. Falin, flight interception trap— 3♂ 1♀ ( CMNC) ; PARA, 11 km SE Zanderij Airport , 30 m (5°23’30’’N, 55°9’30’’W), 20.vi.1999, Z. Falin, flight interception trap— 1♀ ( CMNC) .

Distribution. Known from Brazil (Amapá, Amazonas, and Roraima), Venezuela, French Guiana, and Suriname ( Fig. 6D ). Endemism areas: Brazilian sub-region: Boreal Brazilian dominion: Imeri, Pantepui, Guianan Lowlands, and Roraima provinces (see Morrone 2014; fig. 12).

Remarks. Male genitalia of specimens from French Guiana and north of Brazil (Amapá) present only two sets of bristles and one set of microbristles right beside the FLP sclerite ( Fig. 5T ), while specimens of S. pygidialis examined from other regions (Amazonas and Roraima) exhibit three sets of bristles right beside the FLP sclerite ( Fig. 5S ). However, no significant differences were observed in the external morphology and the shape of parameres among these examined specimens ( Figs. 2B , 4T ). The apparent allopatric distribution between these populations may be artificial due to a lack of collections. Therefore, the discrete differences described here may turn out to be continuous if more specimens are examined along this gap, that is, one form can itself intergrades into the other across this putative chain of populations, or if the forms themselves are indeed discrete, the frequency between them may vary across this population. Thus, we chose to describe at this time these two patterns only as an intraspecific variation of Scybalocanthon pygidialis .

Figures

FIGURE 2. Species of Scybalocanthon, dorsal habitus. A, Scybalocanthon pinopterus; B, S. pygidialis; C–G, S. sexpilotus; H–J, S. trimaculatus; K, S. uniplagiatus. Scale bar: 2 mm.

FIGURE 3. Details of the external morphology in Scybalocanthon. A, Elytral surface in S. chamorroi new species; B, elytral surface in S. acrianus new species; C, pygidium in S. sexpilotus; D, detail of the eighth elytral stria in S. pygidialis (carina point- ed); E, mesofemur in S. kaestneri; F, mesofemur in S. nigriceps; G, mesotarsus in S. moniliatus; H, metatarsus in S. moniliatus; I, mesotibia in S. aereus; J, mesotibia of Canthon arcabuquensis.

FIGURE 4. Aedeagus, detail of parameres in left and right view. A, Scybalocanthon acrianus new species; B, S. adisi new species; C, S. aereus; D, S. aereus (lectotype); E, S. arnaudi new species; F, S. chamorroi new species; G, S. cyanocephalus; H, S. darlingtoni; I, S. federicoescobari new species; J, S. haroldi new species; K, S. kaestneri; L, S. kelleri; M, S. korasakiae; N, S. maculatus; O, S. martinezi new species; P, S. moniliatus; Q, S. nigriceps; R, S. papaxibe new species; S, S. pinopterus; T, S. pygidialis; U, S. sexspilotus; V, S. trimaculatus; W, S. uniplagiatus. Scale bar: 0.5 mm.

FIGURE 5. Sclerites of endophallus. Superior right peripheral (SRP) sclerite. Fronto-lateral peripheral (FLP) sclerite. Complex of axial and subaxial (A+SA) sclerites.Additional sclerite (AS). Set of microbristles (Smb). Set of bristles (Sb). A, Scybalocanthon acrianus new species; B, S. adisi new species; C, S. aereus; D, S. arnaudi new species; E, S. chamorroi new species; F, S. cyanocephalus; G, S. darlingtoni; H, S. federicoescobari new species; I, S. haroldi new species; J. S. kaestneri; K, S. kelleri; L, S. korasakiae; M, S. maculatus; N, S. martinezi new species; O, S. moniliatus; P, S. nigriceps; Q, S. papaxibe new species; R, S. pinopterus; S, S. pygidialis (specimen from Amazonas, Brazil); T, S. pygidialis (specimen from Cayenne, French Guiana); U, S. sexspilotus; V, S. trimaculatus; W, S. uniplagiatus. Scale bar: 0.5 mm.

FIGURE 6. Known distribution of species of Scybalocanthon.