A taxonomic revision of the genus Scybalocanthon Martínez, 1948 (Coleoptera Scarabaeidae: Scarabaeinae: Deltochilini) Author Silva, Fernando A. B. Universidade Federal do Pará, Instituto de Ciências Biológicas, setor de Zoologia, Campus Belém. Rua Augusto Corrêa, 01. Guamá. Belém PA 66075 - 110, Brazil. E-mail: fernandoabsilva @ yahoo. com. br Author Valois, Marcely Programa de Pós-graduação em Zoologia, Universidade Federal do Pará / Museu Paraense Emílio Goeldi. Rua Augusto Corrêa, 01. Guamá. Belém PA 66075 - 110, Brazil. text Zootaxa 2019 2019-07-08 4629 3 301 341 journal article 21174 10.11646/zootaxa.4629.3.1 9419bc9b-dbe4-426c-a34e-f0034848ff99 1175-5326 3995508 1D47B452-0A40-4BC5-9BBA-C06DEB298C9A Key to adult male Scybalocanthon Martínez, 1948 1. Femora completely black.............................................................................. 2 - Femora bicolored, central portion pale yellow, with dark spots at least on the tips ( Figs. 3 E–F)........................ 4 2(1). Pronotum uniformly colored, completely orange ( Fig. 1C ). Brazil ( Acre , Mato Grosso ), Bolivia and Peru ........................................................................... Scybalocanthon aereus ( Schmidt, 1922 ) (in part) - Pronotum bicolored, with yellow and black areas ( Figs. 1L , N–O).............................................. 3 3(2). Elytra black. Pronotum usually with three or five black spots ( Figs. 1 N–O). In some individuals from Loja ( Ecuador ), spots are missing. Ecuador ................................................... Scybalocanthon maculatus ( Schmidt, 1920 ) - Elytra brown. Pronotum with transverse black spot of butterfly or bat shape ( Fig. 1L ). Colombia and Ecuador ....................................................................... Scybalocanthon kelleri Pereira & Martínez, 1956 4(1). Pronotum with a longitudinal dark band on midline ( Figs. 1G , 2B ).............................................. 5 - Pronotum uniformly colored or, if bicolored, lacking longitudinal dark band on midline............................. 6 5(4). Elytra bicolored, with black spot on the anterior portion ( Fig. 1G ). Eighth elytral stria lacking carina at the anterior portion. Brazil ( Amapá , Pará), French Guiana , Venezuela , Trinidad and Tobago ..... Scybalocanthon cyanocephalus ( Harold, 1868 ) - Elytra brown or dark yellow, with black spot almost inconspicuous on its margin ( Fig. 2B ). Eighth elytral stria with thin carina at the anterior portion ( Fig. 3D ). Brazil ( Amazonas , Amapá , Roraima ), Venezuela , Suriname , and French Guyana .......................................................................... Scybalocanthon pygidialis ( Schmidt, 1922 ) 6(4). Black spots on the tips of femora covering approximately 1/15 length of femora ( Fig. 3E )............................ 7 - Black spots on the tips of femora covering approximately 1/5 length of femora, central portion with elliptical yellow spot ( Fig. 3F )................................................................................................ 16 7(6). Pronotum with four black spots, two central spots with triangular shape, and one rounded spot on each side ( Fig. 1K ). Ecuador ................................................................. Scybalocanthon kaestneri ( Balthasar, 1939 ) - Pronotum uniformly colored, lacking spots, or with one elliptical spot on the central portion......................... 8 8(7). Eighth elytral stria lacking carina at the anterior portion....................................................... 9 - Eighth elytral stria with very fine and sharp carina at the anterior portion ( Fig. 3D )................................ 11 9(8). Elytral striae impressed, punctures conspicuous ( Fig. 3A ). Ecuador .............. Scybalocanthon chamorroi new species - Elytral striae weakly impressed, punctures inconspicuous ( Fig. 3B )............................................ 10 10(9). Ventral margin of parameres with an excavation at the basal portion extending one-half of the paramere length. Apex of parameres arrow shaped ( Fig. 4A ). Brazil ( Acre ) and Bolivia ....................... Scybalocanthon acrianus new species - Ventral margin of parameres straight, lacking excavation. Apex of parameres subrectangular ( Fig. 4B ). Brazil (Amazonas) and Ecuador .................................................................. Scybalocanthon adisi new species 11(8). Left paramere lacking acute projection on dorsal margin and lacking bilobate excavation on ventral margin ( Figs. 4E, S ).. 12 - Left paramere with acute projection on dorsal margin and bilobate excavation on ventral margin ( Figs. 4I, O, R, W )..... 13 12(11). Ventral margin of parameres curved outward on its apical one-half ( Fig. 4E ). Peru , Ecuador , and Colombia .................................................................................... Scybalocanthon arnaudi new species - Ventral margin of parameres straight on its apical one-half ( Fig. 4S ). Peru ...... Scybalocanthon pinopterus ( Kirsch, 1873 ) 13(11). Bilobate excavation of ventral margin of left paramere wide and deep, extending at least one-half of the paramere margin in the lateral view ( Fig. 4O ). Ecuador and Colombia ................................ Scybalocanthon martinezi new species - Bilobate excavation of ventral margin of left paramere short, not reaching one-half of paramere margin in the lateral view ( Figs. 4I, W )............................................................................................. 14 14(13). Bilobate excavation of ventral margin of left paramere extending along one-third of the paramere margin ( Fig. 4W ). Brazil ( Acre , Amazonas, Mato Grosso , Rondônia , Pará)....................... Scybalocanthon uniplagiatus ( Schmidt, 1922 ) - Bilobate excavation of ventral margin of left paramere extending along one-fourth of the paramere margin ( Figs. 4I, R )... 15 15(14). Bilobate excavation of ventral margin of left paramere deeper than wide in lateral view ( Fig. 4I ). Colombia ............................................................................. Scybalocanthon federicoescobari new species - Bilobate excavation of ventral margin of left paramere wider than deep in lateral view ( Fig. 4R ). Brazil (Pará, Tocantins ) ........................................................................ Scybalocanthon papaxibe new species 16(6). Pronotum uniformly colored, or with faint brown spot close to anterior or posterior margin (as Figs. 1C, E, M ).......... 17 - Pronotum bicolored, with distinct and variable spots........................................................ 21 17(16). Elytra uniformly colored, completely dark brown or black ( Figs. 1D, M )........................................ 18 - Elytra bicolored, with yellow and black areas (as Figs. 1D, E, S )............................................... 19 18(17). Elytra usually dark brown or black ( Fig. 1M ). Ventral margin of parameres with an excavation on basal half.Apex of parameres arrow-shaped ( Fig. 4M ). Brazil ( Minas Gerais and São Paulo )................... Scybalocanthon korasakiae Silva, 2011 - Elytra usually light brown ( Fig. 1C ). Ventral margin of parameres straight, lacking excavation. Apex of parameres subrectangular ( Fig. 4 C–D). Brazil ( Acre , Mato Grosso ), Bolivia and Peru ........ Scybalocanthon aereus ( Schmidt, 1922 ) (in part) 19(17). Elytra with horizontal yellow spot only on the central portion ( Fig. 1E ). Brazil ( Bahia )......................................................................................... Scybalocanthon batesi Vaz-de-Mello & Silva, 2017 - Most of elytral surface yellow, brown or black spot only on elytral margin and anterior portion of elytra ( Figs. 1J, S )..... 20 20(19). Body surface with metallic sheen ( Fig. 1J ). Parameres subrectangular, lacking excavation on the ventral margin ( Fig. 4J ). Venezuela ................................................................. Scybalocanthon haroldi new species - Body surface opaque or with silky sheen ( Fig. 2S ). Parameres arrow-shaped, with an excavation on the ventral margin ( Fig. 4Q ). Argentina , Brazil ( São Paulo , Rio de Janeiro , Paraná ), and Paraguay ....... Scybalocanthon nigriceps ( Harold, 1868 ) 21(16). Elytral disk bicolored, with yellow and black spots on disk ( Fig. 1H ). Colombia .................................................................................................... Scybalocanthon darlingtoni ( Paulian, 1939 ) - Elytra unicolored, completely dark brown or black, or light colored with narrow black margin....................... 22 22(21). Central portion of dorsal surface of head yellow ( Figs. 1 C–G) or completely silky brown. Pygidium bicolored, central portion with elliptical black spot ( Fig. 3C ). Bolivia , Brazil (Amazonas, Pará, Rondônia , Roraima ), Colombia , Venezuela , and Peru ......................................................... Scybalocanthon sexspilotus ( Guérin-Méneville, 1855 ) - Head completely dark brown or black. Pygidium unicolored.................................................. 23 23(22). Eighth elytral stria with very fine and sharp carina on anterior portion (as in Fig. 3D ). Elytral surface opaque. Pronotum usually with three spots along midline (anterior spot triangular in shape; posterior spots rounded in shape) and one rounded spot on each side of midline ( Fig. 1N ). In some individuals, anterior and posterior spots fused on midline ( Fig. 1O ). Parameres narrowed at the central portion in the lateral view ( Fig. 4N ). Ecuador ................... Scybalocanthon maculatus ( Schmidt, 1920 ) - Eighth elytral stria lacking carina. Elytra with metallic sheen. Pronotum differently colored. Parameres not narrowed at the central portion in the lateral view ( Figs. 4V, P )............................................................. 24 24(23). Pronotum with three black spots (two rounded spots on each side of midline anteriorly and one quadrate spot on midline posteriorly) ( Fig. 2J ). In some individuals, anterior spots are missing, in others spots are fused and two smaller additional spots are present laterally ( Figs. 2 H–I), endophallus with microbristles right beside the FLP sclerite ( Fig. 5V ). Colombia and Ecuador ............................................................... Scybalocanthon trimaculatus ( Schmidt, 1922 ) - Pronotum with two black spots along midline (anterior spot irregular in shape with three angular projection posteriorly; posterior spot quadrate in shape with three small angular projection anteriorly) ( Fig. 1Q ). In some individuals, anterior spot absent or reduced ( Fig. 1R ), endophallus lacking microbristles right beside the FLP sclerite ( Fig. 5O ). Costa Rica , Nicaragua , and Panama ............................................................ Scybalocanthon moniliatus ( Bates, 1887 )