Chiasognathus impubis Parry, 1870

Paulsen, M. J. & Smith, Andrew, 2010, Revision of the genus Chiasognathus Stephens of southern South America with the description of a new species (Coleoptera, Lucanidae, Lucaninae, Chiasognathini), ZooKeys 43 (43), pp. 33-63 : 48-50

Chiasognathus impubis Parry, 1870

Figs 4, 16–17, 29

Chiasognathus impubis Parry, 1870: 68 , original combination. Type material: Lectotype male (BMNH) designated by Chalumeau and Brochier (1995) labeled a) circular label “Mendoza”; b) handwritten on blue-gray paper “ C. impubis Ph. ”; c) red circled label “Type”; d) bordered label “ Bomansodus impubis [‘93] / (Parry) / Det. F. Chalumeau & B. Brochier.” Paralectotype male (MNHN) labeled a) “ impubis Parry , Chili / [ex. Musaeo E.D. Brown] / [ex. R. Oberthür]. Type locality: “ Chili … Mendoza, on the eastern side of the Cordillera.”

Description. Length: 24.5–34.5 mm. Width: 11.5–14.9 mm. Color: Reddish brown, everywhere with weak green or purple metallic reflections. Pronotum, head, and scutellum with stronger reflections. Head: Form subquadrate. Surface punctate; punctures fine to coarse, generally setose with short to long setae. Anterior margin of head sinuate, not strongly produced beyond anterior angles, lacking median nasus (anterior margin at middle rarely weakly binodose). Anterior angles obtusely rounded in dorsal view. Male mandibles cylindrical, 1.5–2× as long as head, externally almost straight until curving internally abruptly before apex. Dentate carina internally on dorsal mar- gin only in basal half (in basal half variably reduced to 1–2 teeth or low carina), becoming internal in apical half; additional dorsal tooth occasionally present near apex in male majors; apex not hooked upwards, lacking patch of setae. Base of mandibles lacking ventral tooth. Female mandible externally straight, dorsally flattened, with median internal tooth. Galeal brush elongate, 2–3× longer than mentum (except labial palps of females subequal to mentum). Antennal scape with sparse area of long setae present in males. Pronotum: Posterior and lateral angles dentate, lateral angle more strongly so in males. Lateral margins indistinct, often obsolete anteriorly (occasionally distinct in major males). Dorsal surface nearly evenly convex, not strongly ridged, longitudinal median furrow weak, weak depressions indicated either side of disc before middle in most specimens. Surface with distinct, moderately long setae in females, short setae in depressions and long setae along anterior margin in males. Elytra: Surface shiny, appearing smooth, actually densely punctate, weakly wrinkled, setose; setae scale-like, microscopic, often abraded; females with scattered longer bristle-like setae as on pronotum, bristles distinct macroscopically. Apex obtusely angulate, lacking spine. Epipleuron strongly concave. Legs: Protibiae elongate, serrate externally; ventral surface along internal margin with teeth well developed in males, lacking in females. Male genitalia: Flagellum long, length more than 3× length of parameres and basal piece together (Fig. 4).

Distribution. This species is distributed widely in central Chile (Fig. 29). Chalumeau and Brochier (2007) listed specimens from Lago Chapo and Llanquihue in Región X Los Lagos, but we did not examine any specimens from these localities.

CHILE (51): Biobío (7): “ Arauco ”; La Araucanía (44): Cherquenco, Cunco, Curacautín, Las Raíces, Lonquimay, Malalcahuello, Cordillera de Malleco , Manzanar, Nahuelbuta, Victoria ; Villarrica. Los Ríos (1): “Valdivia”. No data (2).

Temporal distribution. January (13), February (8), June (3), July (2), October (1), November (7), December (13).

Diagnosis. Males of this species can be distinguished by the shiny pronotum and elytra (Fig. 16) in combination with the apex of the elytron being angulate (not spinose or rounded). Often the lateral margin of the pronotum is obsolete in the apical half, but in larger males the margin may be distinct. The long male protibiae, long flagellum of the male genitalia, and the distinctly visible bristles scattered on the elytra of females (Fig. 17) will easily separate this species from C. latreillei .

Remarks. The identity of C. impubis is often incorrect in collections, and the species is generally treated as C. latreillei by commercial dealers and in Mizunuma and Nagai (2001). Based on examination of the lectotype, Chalumeau and Brochier (2007) correctly determined the identity of this species but placed it in their genus Bomansodus . The characters on which the genus are based are not robust, especially the effaced lateral margin of the pronotum, which is not consistently expressed even within the species. Furthermore, the shape of the protibiae, epipleuron, elytral margin, and mandibles of both sexes argue for a close relationship with C. mniszechii , and, to a lesser extent, C. grantii and C. jousselinii . Females of C. impubis are the only ones in the genus to have macroscopically visible scattered bristles on the elytra.

Figures Ι6–Ι7. Dorsal habitus of C. impubis . Ι 6 male, and Ι 7 female.

Other species may have scattered bristles, but when present they can only be seen under magnification.

The lectotype was reported from “ Chili … Mendoza, on the eastern side of the Cordillera” ( Parry 1870), a somewhat nonsensical combination that could correspond to the area east of Volcán Chillán. This area is currently in Chile, but is depicted as being in Mendoza on maps dated slightly earlier ( Greenleaf 1840). Ocampo and Paulsen (2008) followed Maes (1992) and listed the species from Argentina. While it is probable that the species occurs in eastern Neuquén Province, we do not know of any recent records of this species from Argentina.