Scybalocanthon kaestneri (Balthasar, 1939)

(Figs. 1K, 3E, 4K, 5J, 6E)

Canthon kästneri Balthasar, 1939: 193, 227 (original description); Vulcano & Pereira 1967: 552 (distribution, identification key).

Canthon kaestneri: Blackwelder 1944: 199 (checklist); Pereira & Martínez 1956: 114 (comment); Krajcik 2006: 28 (catalog); Carvajal et al. 2011: 314 (cited for Ecuador); Krajcik 2012: 63 (catalog).

Scybalocanthon kästneri: Vulcano & Pereira 1964: 616 (distribution).

Scybalocanthon kaestneri: Halffter & Martínez 1977: 68 (checklist); Carvajal et al. 2011: 314 (cited for Ecuador); Bezdek & Hajek 2011: 363 (catalog of types); Chamorro et al. 2018: 87 (fig. 10B), 98 (cited for Ecuador); Chamorro et al. 2019: 229, 230 (catalog of dung beetles species from Ecuador).

Diagnosis. Specimens of S. kaestneri are readily distinguishable from all other species by pronotum with four black spots (two central spots with triangular shape and two lateral spots rounded) (Fig. 2K); femora almost completely yellow or brown, with black spots only on the tips (Fig. 3G); parameres of aedeagus slightly asymmetrical, dorsal margin of left paramere strongly curved outward at apical portion (Fig. 4K); endophallus with bristles right beside the FLP sclerite (Fig. 5J); and additional sclerite (AS) absent (Fig. 5J). A specimen from Napo, Ecuador, has only three black spots on pronotum (one spot at posterior margin with triangular shape and two lateral spots rounded).

Description. Body. Oval-elongate, with variable metallic sheen. Surface completely microgranulate. Color. Head and elytra opaque, pronotum with metallic sheen. Most of pronotum, hypomera, prosternum, mesoventrite, central portion of metaventrite, metaepisternae, lateral portion of abdominal ventrites, pygidium, and legs yellow or light brown. Head, some spots of pronotum, elytra, and central portion of abdominal ventrites black. Length. 9.0–10.0 mm. Thorax. Anterior angles of pronotum approximately 90°. Lateral margin strongly curved outward at the middle portion. Elytra. Striae thin and impressed, with elliptical punctures. Eighth stria with a thin carina at the anterior portion. Aedeagus. Parameres slightly asymmetrical, obliquely truncate apically (Fig. 4K). Dorsal margin of parameres curved inward from the basal to medial portions, and curved outward at the apical portion. Ventral margin of parameres curved inward at the basal portion and substraight from the medial to apical portions. SRP circular, with rounded handle-shaped extension (Fig. 5J). FLP subelliptical, with dense set of bristles right beside it (Fig. 5J). A+SA with two superposed and elongate sclerites (Fig. 5J).

Type material. Canthon kaestneri Balthasar, lectotype ♀ (here designated; NMPC): “ Equador ” // “TY- PUS” // “ Kastneri / m. ” // “ Scybalocanthon / kaestneri (Balth.) / Det. B. D. Gill’ 96” // “ LECTOTYPE / Canthon ♀ / kaestneri / Balth / des. F. Z. Vaz-de-Mello / 2013”. Paralectotypes 2♀ (NMPC): “Mera / Ecuador ” // “Typus” // “ PARALECTOTYPE / Canthon ♀ / kaestneri Balth. / des. F. Z. Vaz-de-Mello ” .

Non-type material [ 18 males, 36 females]: ECUADOR: MORONA-SANTIAGO, Untsuants sitio 4, 1100 m, 20.i.2002, J. Celi & M. Ortega, pitfall trap, human feces— 1♂ 1♀ (CMNC) ; Untsuants sitio 6, 1100 m, 23.i.2002, J. Celi & M. Ortega, pitfall trap, fish— 1♀ (CMNC) ; Untsuants sitio 7, 900 m, 23.i.2002, J. Celi & M. Ortega, pitfall trap, human feces— 1♀ (CMNC) ; Bosque Domono, 22.viii.1997, 1650 m, C. Carpio— 1♂ 1♀ (CEMT) ; PASTA- ZA, 22 km SE Puyo, 900 m (1°37’11’’S, 77°50’40’’W), 12–16.vii.1976, S. Peck, forest, dung traps (dung traps 39–41)— 1♀ (CMNC) ; 22 km SE Puyo, 900 m (1°37’11’’S, 77°50’40’’W), 12–16.vii.1976, S. Peck, forest, carrion traps (carrion traps 42–43)— 1♂ (CMNC) ; 25 km NNE Puyo, 1000 m (1°18’19’’S, 77°52’59’’W), 4–13.vii.1976, S. Peck, forest, dung traps (dung trap 25-27)— 3♂ 16♀ (CMNC, MZUFPA) ; 9 km ESE Veracruz, 900 m (1°33’49’’S, 77°53’8’’W), 22–24.viii.1975, R. Webster, forest, dung traps— 1♂ 1♀ (CMNC) ; Llandia, 17 km N Puyo, 1000 m (1°21’3’’S, 77°58’4’’W), 16.vii.1994, F. Génier, remnant rainforest, hand collecting— 1♂ (CMNC) ; Llandia, 17 km N Puyo, 1000 m (1°21’3’’S, 77°58’4’’W), 19.vii.1994, F. Génier, remnant rainforest, feces trap— 4♂ 3♀ (CMNC) ; Llandia, 17 km N Puyo, 1000 m (1°21’3’’S, 77°58’4’’W), 20.vii.1994, F. Génier, remnant rainforest, feces trap— 1♀ (CMNC) ; Oglán River, 29.x. 2008, 809 m, F. Gallo & E. Camillo— 1♀ (CEMT) ; Mera, Estação Biológica Pinto Mirador UTE [Usina Termelétrica] (78°06’29”W, 1°27’25”S), 22.iii.2012, pitfall pig feces, 1000 m, C. Luzuriaga— 5♂ 9♀ (CEMT) ; Mera, Estação Biológica Pinto Mirador UTE [Usina Termelétrica] (78°1’00”W, 2°31’59”S)— 1♂ (CEMT) ; NAPO: Puerto Napo, 480 m—2 [unsexed specimens] (MQCAZ) .

Distribution. Known from Ecuador (Fig. 6E). Endemism areas: Brazilian sub-region: Boreal Brazilian dominion: Napo province (see Morrone 2014; fig. 12).