Chileistomus Weinreich, 1960

Grossi, Paschoal C., 2009, Generic limits in South American stag beetles: taxa currently misplaced in Sclerostomus Burmeister (Coleoptera: Lucanidae: Lucaninae: Sclerostomini), Zootaxa 2139, pp. 23-42 : 37-38

Genus Chileistomus Weinreich, 1960 , new status

Type species: Lucanus cucullatus Blanchard, 1842 , by original designation ( Weinreich 1960: 74).

Description. Length: 10.0–18.4 mm. Width: 3.8–6.9 mm. Head: Shape enlarged in males, almost as wide as both elytra together. Vertex broadly, semicircularly or parabolically excavated, excavation scarcely punctate posteriorly to moderately punctate anteriorly, punctures moderate to fine; lateral margin of excavation subcarinate above antennal insertions. Head with anterior margin (clypeus) strongly declivous before labrum in males, not declivous in females. Labrum in males setose, projected ventrally, concealed when mandibles closed; in females, labrum prominent, semicircular, projected anteriorly, visible when mandibles closed. Gena narrow, longer than eye, sides converging anteriorly, not continuous with anterior angle of head, punctate; punctures dense, moderate. Temporal processes lacking. Mandible as long or longer than length of head in males, upwardly curved, broadest at base, narrowing to acute apex, punctate; punctures fine, dense; mandibular dentition serrate internally with 3–5 conical, rounded teeth and bifid basal tooth; female mandibles simple with acute apex and single or bifid internal tooth. Lacinia sclerotized, hook-like. Antennomeres of club more than half glabrous with few scattered setae, tomentose area confined to distal surface of lamellae. Pronotum: Form broadest in basal third, broadly rounded anterolaterally. Disc anteromedially variably developed from slightly raised, bifurcate prominence (male minors, females), to large, conical, weakly bifurcate protuberance (horn); horn flattened dorsally in the same plane as disc and projecting to median of head (male majors); disc with weak median depression. Anterior angles produced, subacute. Lateral margin with shining bead. Posterior angles thickened, subdentate. Vestiture consisting of broken patches of scales along lateral margin. Elytra: Disc punctate; punctures everywhere dense, nearly uniform in size, varying only from moderate to large. Vestiture consisting of scales, scales forming spots or coalesced into bands on disc. Wings: Fully developed. Legs: Mesotibiae and metatibiae each with 1 large, external tooth below middle; 0–2 smaller teeth proximally. Apex of metatibia acute. Male genitalia: Genital capsule and aedeagus simple, lacking additional lobes. Everted internal sac straplike, terminating in a bulbous appendage bearing a short, hooked flagellum (Fig. 6).

Distribution. Argentina and Chile ( Paulsen 2005).

Diagnosis. This genus differs from other Lucanidae in the following combination of characters: antennomeres of the club mostly glabrous; elytra densely, uniformly punctate (not striate); elytral vestiture consisting of discal spots of scales, spots occasionally coalesced into bands; male with weakly bifurcate pronotal horn anteromedially; horn extending over head; male mandibles more or less triangular, serrate, with peg-like teeth internally, lacking ventral row of setae; male genitalia with capsule simple, everted internal sac straplike with bulbous tip and flagellum (Fig. 6); fully winged.