Scybalocanthon nigriceps

Scybalocanthon nigriceps (Harold, 1868)

(Figs. 1S, 3F, 4Q, 5P, 6F)

Canthon nigriceps Harold, 1868: 12, 49 (identification key and description); Harold 1869: 992 (catalog); Heyne-Taschenberg 1908: 61 (description); Gillet 1911: 31 (catalog); Schmidt 1922: 65, 78 (diagnosis); Balthasar 1939: 193 (redescription); Pêssoa & Lane 1941: 416, 419 (catalog and remarks); Blackwelder 1944: 200 (checklist); Krajcik 2006: 29 (catalog); Krajcik 2012: 64 (catalog).

Scybalocanthon nigriceps: Pereira & Martínez 1956: 115, 119 (catalog and identification key); Vulcano & Pereira 1964: 638 (catalog); Vulcano & Pereira 1967: 555 (distribution, identification key); Halffter & Martínez 1977: 67 (species list); Vazde-Mello 2000: 194 (checklist); Vaz-de-Mello & Silva 2017: 144–145 (identification key and lectotype designation).

Diagnosis. Specimens of S. nigriceps are readily distinguishable from all other species by the body surface opaque; elytra bicolored, most of elytral surface yellow, black coloration restrict to elytral edge (Fig. 1S); femora with black spots on the basal and apical third, central portion with elliptical yellow spot (Fig. 3F); parameres of aedeagus arrow shaped, with an excavation ventrally (Fig. 4Q); and endophallus with additional sclerite (AS) absent (Fig. 5P).

Description. Body. Oval-elongate. Surface completely microgranulate. Color. Body opaque. Pronotum, hypomera, metaepisternae, metaventrite, most of elytra, abdominal ventrites, pygidium, coxae, and the middle of femora yellow or brown. Head, margin of elytra, prosternum, mesoventrite, mesoepisternae, trochanters, proximal and distal portions of femora, and tibiae dark brown or black. Length. 8.5–10.5 mm. Thorax. Anterior angles of pronotum approximately 90°. Lateral margin strongly curved outward. Elytra. Striae thin, punctures conspicuous. Eighth stria effaced at the basal third, with a thin carina at the anterior portion. Aedeagus. Parameres slightly asymmetrical (Fig. 4Q). Dorsal margin of right paramere curved inward from the basal to medial portions, apical portion curved outward. Ventral margin of right paramere with a rounded excavation at the basal portion, from the medial to apical portions substraight. Dorsal margin of left paramere curved inward from the basal to medial portions, apical portion with an inconspicuous pointed projection. Ventral margin of left paramere curved inward at the basal portion, and substraight from the medial to apical portions. SRP circular, with curved handle-shaped extension (Fig. 5P). FLP short, comma-shaped, with microbristles right beside it (Fig. 5P). A+SA with two superposed and elongate sclerites (Fig. 5P).

Type material. Canthon nigriceps Harold, lectotype ♂ (MNHN). See Vaz-de-Mello & Silva (2017).

Non-type material [52 males, 36 females, 10 unsexed specimens]. ARGENTINA: MISIONES, Urugua, Reserva Fundación Vida Silvestre Argentina, 5.ii.2014, G. Zurita, A. Gomez, V. Gimenez— 1♂ 1♀ (CEMT). BRA- ZIL: PARANÁ: Altamira do Paraná, Estrada d’Água da Bola (52°42’ W, 24°52’S), 21.i.2011, G. Weiss & P. Grossi— 1 [unsexed specimen] (CEMT); Londrina, Mata Godoy (23°27’ S, 51°15’W), 17.i.1985, J. Lopes— 3♂ 1♀ (CMNC); same locality, 28–31.i.1990, S.A. Marshall— 7♂ 5♀ (CMNC); Ponta Grossa (25°6’3’’ S, 50°9’54’’W), 17.i.1939, Ca- margo— 1♂ (CMNC); Londrina, xii.1998, I.M. Medri—1 [unsexed specimen] (CEMT); Cornélio Procópio, Parque Estadual Mata São Francisco (50°34’20” W, 23°09’20”S), 19.ix.2009, N. Cipola— 2♂ (CEMT); RIO DE JANEIRO: Itatiaia, 7.xi.1991, J.R. Celso— 1♂ (CEMT); Itatiaia (44°37’19,6” W, 22°25’57,6”S), xii.2011, pitfall, R Andrade, C Araujo—1 [unsexed specimen] (CEMT); Nova Friburgo, xi.1991, [anonymous]—1 [unsexed specimen] (CEMT); SÃO PAULO: Serra do Japi, Atlantic rainforest (46°56’ W, 23°14’S), 1998, 1050 m, M.I.M Hernández— 28♂ 20♀ (CEMT); Campinas, ii.1998, [anonymous]—4 [unsexed specimens] (CEMT); São Paulo (23°32’ S, 46°37’W), xii.1945, Guérin— 1♀ (CMNC). PARAGUAY: CAAZAPÁ, Caazapá (26°11’46’’ S, 56°22’4’’W), 15–30.i.1991, G. Arriagada— 3♂ 4♀ (CMNC); Estero Cristal, xii.1999, [anonymous]—2 [unsexed specimens] (CEMT); Estancia Condesa / Toro Blanco, San Rafael Reserve, 110 m (26°19’11’’ S, 55°39’57’’W), 8–10.xii.2000, Z.H. Falin, flight interception trap— 1♀ (CMNC); ITAPÚA, Yataí, San Rafael Reserve, 100 m (26°38’17’’ S, 55°39’50’’W), 21– 25.ix.2000, Z.H. Falin, flight interception trap— 5♂ 2♀ (CMNC); Yataí, San Rafael Reserve, 100 m (26°38’17’’ S, 55°39’50’’W), 26–30.ix.2000, Z.H. Falin, flight interception trap— 1♂ 1♀ (CMNC).

Distribution. Known from Argentina, Brazil (Paraná, Rio de Janeiro, and São Paulo), and Paraguay (Fig. 6F). Endemism areas: Chacoan sub-region: Parana dominion: Atlantic and Parana Forest provinces; Chacoan dominion: Chacoan province (see Morrone 2014; fig. 12).