Scybalocanthon arnaudi Silva & Valois, 2019

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 : 314

Scybalocanthon arnaudi Silva & Valois , new species

( Figs. 1D , 4E , 5D , 6E )

Etymology. Named in honor of Patrick Arnaud, a scarabaeidologist who collected part of the type series.

Diagnosis. Specimens of S. arnaudi are similar to those of S. federicoescobari new species, S. martinezi new species, S. papaxibe new species, S. pinopterus , and S. uniplagiatus by having the pronotum uniformly colored, or with one elliptical spot on the central portion ( Figs. 1D , 2A , 1P , 2K , 1I, 1T ); femora almost completely yellow or brown, with black spots only on the tips ( Fig. 3G ); eighth elytral stria with thin carina on anterior portion ( Fig. 3D ); endophallus with bristles right beside the FLP sclerite ( Figs. 5D, R, N, W, H, Q ); and additional sclerite ( AS) absent ( Figs. 5D, R, N, W, H, Q ). They can be distinguished from those of S. federicoescobari , S. martinezi , S. papaxibe , and S. uniplagiatus by the left paramere lacking acute projection on dorsal margin and lacking bilobate excavation on ventral margin ( Fig. 4E ) (other species with acute projection and bilobate excavation on dorsal and ventral margins, respectively); from those of S. pinopterus by the ventral margin of parameres curved outward on its apical one-half ( Fig. 4E ), not straight as in S. pinopterus ( Fig. 4S ).

Description. Body. Oval-elongate. Surface opaque (except pronotum), completely microgranulate. Color. Most of pronotum, lateral portion of hypomera, and middle of femora yellow or light brown. Other parts dark brown.

Length. 8.0–10.0 mm. Thorax. Pronotum with one brown and rounded spot at the anterocentral portion ( Fig. 2B ). In some, spot absent. Anterior angles of pronotum with approximately 90°. Lateral margin strongly curved outward at the middle portion. Elytra. Striae thin and shiny, punctures conspicuous. Eighth stria with a thin carina at the anterior portion. Aedeagus. Parameres slightly asymmetrical ( Fig. 4E ). Dorsal margin of parameres curved inward from the basal to medial portions, apical portion curved outward. Ventral margin of parameres with a rounded excavation at the basal portion, from the medial to apical portions curved outward. SRP circular, with handle-shaped extension ( Fig. 5D ). FLP short, comma-shaped, with two sets of bristles and a set of microbristles right beside it ( Fig. 5D ). A+SA with two superposed and elongate sclerites ( Fig. 5D ).

Type material. Holotype. PERU: LORETO: Rio Pucacuro, bosque de cierro firme poco colinado, 1.xii.2007, pitfall human feces, 213 m, Cesar Moreno— 1♂ ( CEMT) . Paratypes [47 males, 19 females]. PERU : LORETO, 1.5 km N Teniente López [site 2], 230–305 m (2°35’39.6’’S, 76°6’55’’W), 18–26.vii.1993, R. Leschen, flight interception trap— 23♀ 28♂ ( CMNC, MZUFPA) ; Campamento San Jacinto , 175–215 m (2°18.75’S, 75°51.77’W), 3–12.vii.1993, R. Leschen, flight interception trap— 5♀ 9♂ ( CMNC) . HUÁNUCO: Puerto Inca, 20.ii.2005 — 1♀ ( CEMT) ; Tingo Maria , xi.1977, P. Arnaud— 1♀ ( CEMT) ; LORETO: Rio Pucacuro , bosque de cierro firme poco colinado, 1.xii.2007, pitfall human feces, 213 m, Cesar Moreno— 1♂ ( CEMT) . ECUADOR: NAPO, 20 km S Tena , 600 m (1°8’58’’S, 77°50’26’’W), 9–11.vii.1976, S. Peck, forest, dung traps (dung traps 36–38)— 2♂ 2♀ ( CMNC) ; Estación Biológica Jatun Sacha , 21 km E Puerto Napo, 400 m (1°4’5’’S, 77°36’50’’W), 8.vii.1994, F. Génier, virgin rainforest, feces trap— 2♀ ( CMNC) ; Estación Biológica Jatun Sacha , 21 km E Puerto Napo, 400 m (1°4’5’’S, 77°36’50’’W), 9.vii.1994, F. Génier, virgin rainforest, feces trap— 1♂ 1♀ ( CMNC) ; Estación Biológica Jatun Sa- cha, 21 km E Puerto Napo, 400 m (1°4’5’’S, 77°36’50’’W), 11.vii.1994, F. Génier, virgin rainforest, feces trap— 1♂ ( CMNC) ; Estación Biológica Jatun Sacha , 21 km E Puerto Napo, 400 m (1°4’5’’S, 77°36’50’’W), 15.vii.1994, Levy & Génier, virgin rainforest, flight interception trap— 1♂ ( CMNC) ; Estación Biológica Jatun Sacha , 21 km E Puerto Napo, 400 m (1°4’5’’S, 77°36’50’’W), 21.vii.1994, F. Génier, virgin rainforest, carrion trap— 1♀ ( CMNC) ; Scyasu- ni, 20–21.X. 1997, 200m, D. Padilla & I. Tapin— 1♀ ( CEMT) ; ORELLANA: Francisco de Orellana, Rodrigo Borja , IAMOE, 4.vi.2000,A. Dávalos— 1♂ ( CEMT) ; Río Tiputini, Yasuni Research Station (76°24’W, 0°40.5’S), vii.1999, flight intercept trap, A. Tishechkin— 1♀ ( CEMT) ; PASTAZA: Bosque Moretecocha , 3.vii.1996, J. Naranjo— 1♂ ( CEMT) ; Arajuno , 3–11.xii. 2000, 750 m, Maly— 1♀ ( CEMT) ; Estación Científica Yasuní ( PUCE) [site 7], Parque Nacional Yasuní , 215 m (0°38’S, 76°36’W), 27.vii–1.viii.1998, Ratcliffe, Jameson, Smith, Villatoro, lowland rainforest, pitfall trap, dung— 1♂ ( CMNC) . COLOMBIA: AMAZONAS, Leticia , 215 m (4°11’20’’S, 69°56’9’’W), 19–25.ii.1972, H. & A. Howden— 1♀ ( CMNC) ; Leticia , 215 m (4°11’20’’S, 69°56’9’’W), 24–28.ii.1974, S. Peck— 1♀ ( CMNC) ; Los Alpes, Leticia , 213 m (4°4’25’’S, 70°0’5’’W), 23.ii–2.iii.1974, S. Peck, dung trap— 2♀ ( CMNC) ; road end, Leticia , 213 m (4°4’9’’S, 69°59’56’’W), 23.ii–2.iii.1974, S. Peck, dung trap— 1♂ ( CMNC) ;

Distribution. Known from Peru, Ecuador and Colombia ( Fig. 6E ). Endemism areas: Brazilian sub-region: Boreal Brazilian dominion: Napo and Imerí provinces; South Brazilian dominion: Ucayali province (see Morrone 2014; fig. 12).

Figures

FIGURE 1. Species of Scybalocanthon, dorsal habitus. A, Scybalocanthon acrianus new species; B, S. adisi new species; C, S. aereus; D, S. arnaudi new species; E, S. batesi; 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–O, S. maculatus; P, S. martinezi new species; Q–R; S. moniliatus; S. S. nigriceps; T. S. papaxibe new species. Scale bar: 2 mm.

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.