Isocopris rossinii Arias-Buriticá, Bach

Arias-Buriticá, Jorge Armando, Bach, Andressa, Peres, Carlos A., Haugaasen, Torbjørn, Hawes, Joseph E., Azevedo, Renato A. & Vaz-De-Mello, Fernando Z., 2023, Figs. 4 - 10 in Descriptions of Two New Species of Scaphisoma Leach (Coleoptera: Staphylinidae: Scaphidiinae) in Korea, The Coleopterists Bulletin 77 (4), pp. 629-635 : 630-633

Isocopris rossinii Arias-Buriticá, Bach , and Vaz-de-Mello, new species

zoobank.org/ urn:lsid:zoobank.org:act:25BB9AD8-51A5-4A15-BD63-F32A326BB38C

( Fig. 1–3 )

Etymology. This species is named in honor of Dr. Michele Rossini, Italian scarabaeoidologist and good friend of the authors, who carried out the taxonomic revision of Isocopris with FZVM.

Diagnosis. This species is recognized by the following combination of characters: head with fronto-clypeal carina and deep depression in the frons ( Fig. 1 ), both sexes with head margin distinctly notched at the clypeo-genal junction ( Figs. 1a, c ), ventral clypeal process in lateral view large and trapezoidal ( Figs. 1e, f ), metaventral anterior lobe glabrous ( Figs. 1b, d ), morphology of the male genital organ as in Fig. 2 . Females show secondary sexual dimorphism: head with triangular shape, elytral striae from the first to the fourth widened in the central area ( Fig. 1c ).

Description. Male. Length 19.6 mm, width 11.7 mm ( Figs. 1a, b ). Body color black and shiny, with brown setae on both sides of head and pronotum ( Fig. 1a ). Head: Wider than long. Antenna with eight antennomeres. Clypeus emarginate at middle, with two obtuse teeth. Surface of clypeus shiny with smooth wrinkles giving it a wavy appearance. Ventral clypeal process in lateral view large and trapezoidal ( Fig. 1e ). Head margin distinctly notched at the clypeo-genal junction, genal margin broader than clypeus. Fronto-clypeal region with a central and transverse carina of about 2.5 mm and apical ridge flattened ( Fig. 1e ). Clypeo-genal suture clearly visible. Frons with deep and distinct depression ( Fig. 1e ). Pronotum: Wider than long, simple and convex, anteromedial region without humps. Anterior angles acute. Pronotal punctures dense, very shallow and separated by no more than twice their diameter, near posterior margin with shallow and elliptical ocellate punctures. Hypomeron: Shagreened surface with setose punctures spaced about by their diameters, denser on lateral margins, glabrous and smooth in the central area. Prosternum: Shagreened surface with smooth central area, glabrous. Mesoventrite: Shagreened surface. Smooth in the central area and with large, deep ocellate punctures separated by less than their diameters in the lateral areas. Mesanepisternum: Shagreened surface with setose punctures separated by less than one-half their diameter. Metaventrite: Anterior lobe with shagreened surface with wrinkles near suture with mesoventrite. With shallow punctures separated by two and three times their diameters in the lateral areas near the insertion of the mesocoxa. Central area with shiny, glabrous surface ( Fig. 1b ). Metaventral lateral margins with strongly shagreened surface with large and deep ocellatesetose punctures separated by less than their diameter. Metanepisternum: Shagreened surface with large, deep ocellate punctures separated by about their diameters, some points with short setae. Elytra: Striae bicarinate, distinctly impressed and with shagreened surface, with small ocellate punctures throughout, spaced about three to four times their diameters. Interstriae with shagreened surface, with small and shallow punctures, separated by two to three times their diameters. Abdomen: Abdominal ventrites curved and projected at the lateral margin. Shagreened surface with shallow punctures. Anterior area from first to fifth ventrite with a row of large, deep ocellate punctures separated by less than their diameters and denser on the lateral margins. Sixth ventrite compressed in the middle region. Pygidium: Pygidial margin complete. Surface shiny, with small, shallow punctures separated by three times their diameters throughout. Legs: Apical margin of protibia obliquely truncate, inner and apical angles finely acuminate, with few straight setae at the apex. Apical spur abruptly angled near the apex ( Fig. 1a ). Tarsomere 1 of meso- and metalegs as long as the second and third tarsomeres together. Metatibial spur with apical bifurcation ( Fig. 1a ). Aedeagus: Parameres subtriangular in lateral view ( Fig. 2a ). In dorsal view parameres symmetrical with curved apex ( Fig. 2b ). In ventral view subgenital plate present, parameres symmetrical with curved apex and base with spine-shaped projection ( Fig. 2c ). Endophallites: Lamella copulatrix (LC) is large, asymmetrical with two sclerotized processes and a fleshy process with many bristles ( Fig. 2d ). Sclerites of axial and subaxial complex (A+SA complex) with indeterminate shape, more sclerotized in the central area surrounded by a semi-sclerotized membrane ( Fig. 2f ). Superior-right peripheral sclerite (SRP) with a “C” shape, wide and with undefined margins ( Fig. 2e ). Fronto-lateral peripheral sclerite (FLP) as shown in Fig. 2g .

Variation. In males the length varies from 17.5– 19.7 mm and the width from 10–11.5 mm. Some males have a shorter cephalic process (less than 1.5 mm) and the apical ridge of the carina is bicuspid. Female: Length 18.0– 21.1 mm. Width 10.8–11.5 mm. Females differ from males in having a less rounded head, giving the appearance of being triangular, while the cephalic carina changes as mentioned in the variation of males ( Fig. 1f ). Secondary sexual dimorphism present, with the elytral striae from the first to the fourth widened in the central area ( Fig. 1c ). Sixth abdominal ventrite not compressed towards the middle.

Type Material. Holotype: 1♂. Labels:1: {printed text on white label} BRASIL: Acre, Mâncio Lima, Par [que] Na [cional] Serra do Divisor 7°26′46″S 73°39′28″W, FIT. 11-15.xii.2019, R. A.Azevedo. Plot A FIT 1-3 (250) / 2: {printed and handwritten text on red label with black margins } HOLOTYPE ♂ Isocopris rossinii sp. nov. Arias-BuriticÁ, Bach and Vaz-de-Mello, 2023 [ CEMT] . Paratypes: (2♂♂, 4♀♀): Same data as holotype except: 07-11- xii.2019. 1♂. [ CEMT]. BRASIL: Acre, Mâncio Lima, Par [que] Na [cional] Serra do Divisor 7°26′46″S 73°39′28″W, 236 m, 07-09.xii.2019. hum[an] dung. RA Azevedo. 1♂ 4♀♀ . [2♀♀ CEMT, 1♀ INPA, 1♂, 1♀ CERPE]. All Paratypes have a second label: 2: {printed and handwritten text on yellow label with black margins} Isocopris rossinii sp. nov. Arias-BuriticÁ, Bach and Vaz-de-Mello, 2023 PARATYPE.

Distribution and Ecology. Known only from the southwestern Brazilian Amazon from Serra do Divisor National Park, Rondônia province in the South Brazilian Dominion ( Morrone et al. 2022) ( Fig. 3 ), a lowland terra firme site (i.e., non-flooded area) with primary Amazonian forests up to 300 masl. Isocopris rossinii has been sampled using flight interception traps (FIT) and pitfall traps baited with human feces.

Taxonomic Commentaries. Isocopris rossinii belongs to the small- to medium-sized Isocopris species, encompassing I. foveolatus , I. imitator , I. nitidus , I. tarsalis , and I. xacriaba . It is easily separated from the last four species by the cephalic process; I. rossinii has a transverse fronto-clypeal carina as does I. foveolatus , whereas the other species have a conical horn. By external morphology, I. rossinii is related to I. foveolatus , with which it shares the deeply depressed frons and the structure of the fronto-clypeal process. However, it is easily separated by the shape of the ventral clypeal process, the anterior lobe of the metaventrite, which is glabrous in I. rossinii but with long setae present in I. foveolatus , as well as the morphology of the aedeagus and endophallites. The female secondary sexual dimorphism present in the elytral striae of I. rossinii is shared with I. imitator , I. nitidus , and I. tarsalis .

Figures

Fig. 1. Isocopris rossinii, new species. Male: a) Dorsal view, b) Ventral view, e) Head, lateral view. Female: c) Dorsal view, d) Ventral view, f) Head, lateral view. Scale bars: a, b, d, e = 5 mm; c, f = 2 mm.

Fig. 2. Isocopris rossinii, new species. Aedeagus: a) Lateral view, b) Dorsal view, c) Ventral view. d) Lamellae copulatrix, e) Superior-right peripheral sclerite (SRP), f) Sclerites of axial and subaxial complex (A+SA complex), g) Fronto-lateral peripheral sclerite (FLP). Scale bars = 1 mm.

Fig. 3. Distribution map for Isocopris rossinii, new species. Plot A and Plot B represent the collection sites in Serra do Divisor National Park, Acre, Brazil.