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Chalcocopris hesperus

Chalcocopris Burmeister, 1846

MICHELE ROSSINI & FERNANDO Z. VAZ-DE-MELLO
Link: Zootaxa 3920 (2):291-300

Abstract
Species included in the genus Chalcocopris Burmeister, 1846 are reviewed, including the description of a new species
(Chalcocopris inexpectatus sp. nov.) from Central Brazil, and the designation of a neotype for Copris hesperus Olivier,1789.

Introduction
Chalcocopris Burmeister, 1846, was originally introduced as a subgenus of Copris Geoffroy, 1762 (as Copris Latreille), for two species: Scarabaeus hesperus Olivier, 1789, and Copris smaragdina Perty, 1830. Harold (1869), when considering C. hesperus (Olivier, 1789) as the only species in that genus, designated this as the typespecies of Chalcocopris by subsequent monotypy.

The genus Chalcocopris has been so far considered as monospecific and its included species, C. hespera, is an endemic of the Atlantic Forest of the South and Eastern States of Brazil and neighboring areas of Argentina and Paraguay. Along with Isocopris Pereira & Martínez, 1960, Chalcocopris shares an eight-segmented antenna, unique among Western Hemisphere Coprini, being distinguished from Isocopris by the costate lateral elytral stria (flat in Isocopris) and unbordered pronotal posterior margin (bordered in Isocopris). While working on a revision of the genus Isocopris, we were surprised by the finding of a tiny, dark brown new species that in fact belongs to Chalcocopris. Therefore, the aim of this work is to present a taxonomic synopsis of the genus Chalcocopris, describing the second species.

Material and methods
A large sample of individuals of C. hesperus and C. inexpectatus sp. nov. was studied, with special emphasis on external body characters and male genitalia. Several dry-pinned specimens were dissected for the study of their genital structures and, according to the standard methodologies, individuals were firstly softened in hot water for about 5 minutes and then dissected. Male genitalia were cleaned in a 5% KOH solution for 10 minutes and glued in a card-point for a further detailed morphological study. Specimens and male genitalia were then photographed with a camera attached to a stereomicroscope.

Chalcocopris Burmeister, 1846

Copris (Chalcocopris): Burmeister, 1846 (original description); Erichson, 1847 (syn. of Pinotus);
Lacordaire, 1856 (syn. of Copris); Chalcocopris, Harold, 1869 (as genus); Chalcocopris, Harold in Gemminger & Harold, 1869; Gillet, 1911; Luederwaldt, 1929; Luederwaldt, 1931; Paulian, 1938; Pessôa & Lane, 1941; Blackwelder, 1944; Lange, 1947 (as Calcocopris); Pereira, 1954; Martínez, 1959; Pereira & Martínez, 1960; Halffter & Matthews, 1966; Halffter & Edmonds, 1982; Vaz-de-Mello, 2000.

Body shiny black or brownish to emerald green and dull, legs and ventral side black-brownish to cupreous-purplish with metallic reflections, clypeus either evenly coloured or darker on the anterior region. Antennae with eight segments, clypeal margin evenly curved to slightly sinuate in the middle, with two feeble and rounded teeth, margin either weakly reflexed or completely flat. Margins of both genae and clypeus evenly curved or genae slightly wider, distinctly notched in proximity of the clypeo-genal junction and anteriorly elongated with a blunt tooth. Genal suture slightly to distinctly marked, fronto-clypeal suture either with two small tubercles hump-like and a central conical horn or lacking ornaments. Pronotum without anterior protuberances, posterior margin not bordered, lateral margins well curved and almost obtusely angulated at middle to nearly parallel and straight, anterior margin with a smooth and thin bead slightly elevated over the pronotal surface, anterior angles with inner side either straight and weakly sinuated or outwardly curved, external sides obliquely straight to evenly curved,
pronotal punctuation fine and equally distributed. Elytral striae with shallow punctures, deeper at the base and with shallow punctures separated by about three diameters, seventh stria larger, interstriae almost flat to much more convex, eighth interstria clearly swollen. Pygidium either completely bordered or without border at the apex, surface with fine and scattered punctures or with a deeper and homogeneous punctuation. Aedeagus with phallobase either short and strong or slender and thinner, parameres distinctly narrower or much wider and rounded at the apex, dorso-internal margins slightly to strongly concave.
Males and females are distinguished externally by clypeus (somewhat shorter in males) and last abdominal ventrite (medially constricted in males).
Chalcocopris
is undoubtedly related to Dichotomius, Isocopris and Holocephalus, with which it shares the lack of external meso and metatibial transverse carinae, and a coniform to bifurcate ventral clypeal process (Vazde- Mello et al., 2011). It can be distinguished by the combination of eight-segmented antennae (shared only with Isocopris), the pronotal posterior margin unbordered and seventh elytral interstriae very convex at least in apical half (both unique).

Species can be distinguished as follows:

1. Body completely dark brown to black, bright and silky. Clypeus widely and evenly curved, external margin of genae distinctly notched in proximity to the clypeal junction, making anterior part of the genae with an anterad tooth-like projection, frontoclypeal suture either with two small and rounded protuberances at middle or a simple protuberance. Lateral margins of pronotum
almost parallel. Pygidium entirely bordered. Central Cerrado of Brazil and Paraguay . . . . . . . . . . . . . . . . . . . . . Chalcocopris inexpectatus sp.nov.

- Head, pronotum and elytra, dorsally, emerald green (in all but two known specimens), red (in only one known specimen) or black with some metallic tinge (in only one known specimen); Ventral side red in all but one (black) specimen, dull to bright above, shiny metallic below. Clypeus slightly sinuated at middle, with two feeble and blunt teeth, anterior external margin of genae lacking notch or any prolongation. Fronto-clypeal suture with a small tubercle either side and a central conical horn. Lateral margins of pronotum distinctly curved to almost angulate at middle. Pygidium apically without border.
- Atlantic forest of South and Eastern Brazil and neighboring Paraguay and Argentina (Misiones) . . . . . . . . . . . Chalcocopris hesperus


Chalcocopris hesperus

Distribution:

Southern Bahia, all Rio de Janeiro and Espírito Santo, Southeastern Minas Gerais, Eastern São Paulo, Northwestern Paraná and Eastern Santa Catarina in Brazil, Misiones in Argentina, probably also present in Northeastern Rio Grande do Sul in Brazil and in Southeastern Paraguay.

Habitat and natural history:

Species associated to Atlantic forest from sea level to about 1300 m, also present in borders and small open areas surrounded by forest. A primarily coprophagous species, but with records from carcasses and rotten fruits. Diurnal, commonly found perching along forest trails. Very abundant species in all its range even in small forest patches.

Chalcocopris inexpectatus sp. nov.

Distribution: 

Cerrado and Pantanal of Mato Grosso, Mato Grosso do Sul, Goiás and central Minas Gerais in Central Brazil, one record from Southern Paraguay, so probably present in a wider range, maybe including some parts of Chaco.

Habitat and natural history: 

The limited number of specimens with data have been collected either at light or with human-dung baited pitfall traps. The habitat appears limited to the cerrado sensu stricto vegetation and planted Eucalyptus forest. This species appears not to be very abundant or widespread.
The finding of a second species of Chalcocopris, in a different Biogeographical province (the Cerrado) is a good example of how understudied are the South American scarabaeinae dung beetles.

1 Chalcocopris hesperus

2 & 3 Chalcocopris inexpectatus