Isocopris nitidus ( Luederwaldt, 1922 ) Rossini & Vaz-de-Mello, 2017

Rossini, Michele & Vaz-de-Mello, Fernando Z., 2017, A taxonomic review of the genus Isocopris Pereira and Martínez, 1960 (Coleoptera: Scarabaeidae: Scarabaeinae), with description of a new Brazilian species, Journal of Natural History (J. Nat. Hist.) 51 (19 - 20), pp. 1091-1117 : 1107-1109

Isocopris nitidus ( Luederwaldt, 1922) comb. nov., stat. rev.

( Figures 4 and 8 (c))

Pinotus nitidus Luederwaldt, 1922: 5

Description

Medium-sized individuals, body length 13 – 17 mm, body completely black and shining, sometimes with reddish sheen, antennal club yellow. Head: male with clypeus wide, clypeal margin strongly reflexed and plate-like at middle, central margin feebly sinuated to truncated, lateral margins of clypeus sinuated. Female with clypeus triangular and elongated forward, feebly reflexed and very slightly emarginated at middle, margin of head notched at the clypeo-genal junction, genal margin always slightly expanded beyond clypeus. Both sexes with a conical fronto-clypeal horn flanked slightly backward by two small tubercle-like humps, horn of female smaller, frons strongly to feebly depressed at middle. Clypeus and genae completely and shallowly wrinkled, frons with coarse and transverse punctures. Thorax: pronotum simply convex and polished, punctuation very obsolete and shallow, anteromedial protuberance absent, anterior margin with a thin bead, posterior half of pronotum with a median and longitudinal sulcus. Elytra convex and swollen, striae well impressed, interstriae convex, elytral punctuation very fine (similar to pronotum). Prosternum smooth, sometimes with a few short setae, mesosternum granulose, with coarse and shallow punctures associated to short setae, metasternum finely microsculptured on the superior side and along the inner margin of mesocoxae, superior side of metasternum with evanescent and shallow punctures. Abdomen: pygidium entirely bordered, surface with very fine punctures. Legs: anterior margin of fore tibiae obliquely truncated, inner and apical angle acuminated and tooth-like, margin with few straight setae. Apical spur bifid, with posterior tooth very feebly indicated, hind tibiae with apical spur bifurcated. Male genitalia: parameres and lamella copulatrix as shown in Figure 4 (e – g).

Distribution

French Guiana, Brazil (Acre, Amazonas, Roraima, Pará, Amapá, Mato Grosso), Peru ( Figure 8 (c)). Species exclusive of Amazon forests, to date rarely found in the cerrado .

Remarks

In 1922, Luederwaldt described Pinotus nitidus from Brazil but later Pereira (1953, p. 388) synonymised this species name with Dichotomius imitator ( Felsche 1901) . The examination of the types of both species allowed us to resurrect Pinotus nitidus Luederwaldt, 1922 from synonymy. Indeed, external morphology and genital characters led us to consider P. nitidus within the genus Isocopris under the following new status and combination: Isocopris nitidus ( Luederwaldt 1922) (ICZN 1999, art. 48).

Isocopris nitidus is morphologically very similar to I. imitator , and the pronotal and elytral punctuation (denser and larger in I. imitator ) and, sometimes, body size ( I. nitidus usually smaller than I. imitator ) appear to be the only informative external characters to distinguish these two species. However, body size should be used very carefully, as sometimes females of I. nitidus have the same size as major individuals of I. imitator . Characters observed on the male genitalia (shape of the parameres and lamella copulatrix, Figures 3 (e – g) and 4(e – g)) are instead very useful to easily separate I. nitidus from I. imitator , also suggesting their possible close relationship within the genus.

According to current knowledge, both species occur across the southern belt of the Amazon forest (Acre, Rondônia, north of Mato Grosso, southern Pará), and I . nitidus reaches the northern regions of the Amazonas and Roraima States.

Luederwaldt (1931) described australis as a new variety of Pinotus nitidus on a male singleton belonging to the type series of P. nitidus and collected in Porto Alegre. Along with this individual, Luederwaldt mentioned another specimen deposited in the Museum of São Paulo and belonging to the same variety (one female, see Pereira 1942). According to Luederwaldt (1931) and then Pereira (1942), the variety australis differs from the nominotypical form by having the elytral striae thinner, interstriae flattened, cephalic horn without tubercles at both sides, sulcus of the posterior pronotal margin weaker, finely granulated in male, with rounded punctures in female, anterior angles of the pronotum more rounded, posterior angles acute, spurs of the hind tibiae not truncated. More importantly, Pereira (1942) also reported differences in the shape of the male genital organs, as well as the presence of hairs at the apex of the parameres of P. nitidus australis . Nonetheless, he preferred to maintain the taxonomic arrangement proposed by Luederwaldt.

Here, we examined the type of P. nitidus australis , and the nine antennal segments and the tips of the parameres with hairs, alongside other characters shared with the species belonging to the subgenus Dichotomius ( Vaz-de-Mello et al., 2011), lead us to consider this variety to be a valid species name under the following new status and combination: Dichotomius (D.) australis ( Luederwaldt, 1931).

Type specimens examined

Of Pinotus nitidus : lectotype here designated (1 ♂ FIOC): 1: TIPUS (printed on red label with black border) . 2: ♂ 3: Tapajos , Itaituba (handwritten in italic on black-bordered cream label with ‘ J.F. Zikán ’ printed outside border) . 4: Pinotus nitidus n. sp., i. lit. ( Luederwaldt handwritten in italic on cream label) . 5: LECTOTYPE, Pinotus nitidus Lued ‘ 22, des. F.Z. Vaz-de-Mello, 2016 (printed and handwritten on red label with black border). Paralectotype (1 ♂ MZSP): 1: TIPO (printed on red label with black border) . 2: Tapajos , Itaitubas (handwritten in italic on cream label) . 3: Pinotus nitidus Lüd., Lüd. det. 26 (handwritten – probably not by Luederwaldt – on cream label). 4: 17,451 (printed on white label). 5: PARALECTOTYPE, Pinotus nitidus Lued ‘ 22, des. F.Z. Vaz-de-Mello, 2016 (printed and handwritten on red label with black border).

Of Pinotus nitidus australis : lectotype here designated (1 ♂, MZSP): 1: COTIPO (printed on pink label with black border) . 2: 17,453 (printed on white label). 3: rounded blue label. 4: Pinotus nitidus, Lueder. Lueder. det. 1927 (handwritten on white label). 5: Rio Grande do Sul, P. Alegre, XI-27 (printed and handwritten on white label) . 6: Pinotus nitidus var. australis Lueder., Lueder. det. 1931 (handwritten on white label). 7: Aedeagus mounted on white cardboard. 8: LECTOTYPE, Pinotus nitidus var. australis Per., 1942 , ♂, des. F.Z. Vaz-de-Mello, 2016. Paralectotype (1 ♀ MZSP): 1: COTIPO (printed on pink label with black border) . 2: 17,454 (printed on white label). 3: rounded blue label. 4: B. Retiro, I, 96 (printed in blue on cream label). 5: Pinotus nitidus var. australis Lueder., Lueder. Det. 31. (handwritten on white label). 6: F. Pereira, 941 (handwritten in blue on white label). 7: PARALECTOTYPE, Pinotus nitidus var. australis Per., 1942 , ♀, des. F.Z. Vazde-Mello, 2016.

Other material examined

BRAZIL: Acre: Xapuri . Reserva Chico Mendes. 10°20.975 ’ S, 68°40.840W. 19 – X – 2008 (1 ♀ CEMT) . Amapá: Serra do Navio . 00°53 ʹ 06 ” N, 51°52 ʹ 53 ’ W. IX – 2000 (1 ♀ CEMT) . Amazonas: 90 km N Manaus . X – XI – 1996 (1 ♂ CEMT) . Mato Grosso: Cláudia. Fazenda Continental. 11°24 ʹ 57 ” S, 55°19 ʹ 02 ” W. 20 – II – 2011 (1 ♂ CEMT) . Querência. Fazenda São Luiz. 12° 39.321 ’ S, 52°21.937 ʹ W. II – 2009 (2 ♂♂ CEMT) . Pará: Redenção. Pinkaiti Aik. 07°46 ’ S, 51° 58 ʹ W. XI – 1999 (1 ♂, 1 ♀ CEMT) . Monte Dourado. Jari Cellulose. 00°41 ’ S, 52°48 ʹ W (1 ♂ CEMT) ; Roraima: Ilha de Maracá . IX – 1996 (2 ♂♂, 4 ♀♀ CEMT) . Amajari. Ilha de Maracá . 03°21.866 ʹ N, 61°27.601 ʹ W. 16 – V – 2009 (1 ♀ CEMT) . FRENCH GUYANA: Cayenne: Nouragues . 4º05 ʹ N, 52º41 ʹ W (1 ♂, 2 ♀♀ CEMT) . Paracou Field Station , 5°02 ʹ N, 53°0 ʹ W (1 ♀ CEMT) PERU: Madre de Dios: 12°15 ’ S, 68°59 ʹ W . II – IV – 2009 (2 ♀♀ TLc).

Figures

Figure 3. Isocopris imitator. (a, d) Dorsal habitus of male and female. (b–c) Details of the pronotal and elytral punctuation. (e–f) Dorsal and lateral side of the parameres. (g) Lamella copulatrix. (h) Apical spur of the fore tibia.

Figure 4. Isocopris nitidus. (a, d) Dorsal habitus of male and female. (b–c) Details of the pronotal and elytral punctuation. (e–f) Dorsal and lateral side of the parameres. (g) Lamella copulatrix.

Figure 8. Distribution maps of the genus Isocopris. (a) I. foveaolatus and I. xacriaba. (b) I. imitator and I. tarsalis. (c) I. hypocrita and I. nitidus. (d) I. inhiatus.