Zikanius aurocinctus ( Boileau, 1899 ) Boileau, 1899

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 : 34-36

Zikanius aurocinctus ( Boileau, 1899) , new combination

(Figs. 5, 11)

Sclerostomus aurocinctus Boileau 1899: 298 (description); van Roon 1910: 44 (catalog) ( Sclerognathus ); Lüderwaldt 1935: 555 (monograph); Didier & Séguy 1953: 165 (779) (catalog) (erroneously as Pycnosiphorus ); Benesh 1960: 35 (catalog); Krajcik 2001: 19 (catalog); Krajcik 2003: 165 (catalog).

Sclerostomus marginivillosus Lüderwaldt 1935: 535 (description); Didier & Séguy 1953: 166 (793) (catalog) (erroneously as Pycnosiphorus ); Benesh 1960: 36 (catalog); Weinreich 1960: 80 (synonymy); Krajcik 2001: 19 (catalog).

Sclerostomus (Altitatiayus) aurocinctus ; Weinreich 1960: 90 (revision, key, and illustrations); Maes 1992: 51 (catalog); Grossi & Racca-Filho 2004: 4 (key).

Description. Length 15.0–19.0 mm. Width: 6.0–7.0 mm. Color: Color of body reddish-brown to dark brown, with pattern formed by marginal band of long setae on elytra. Head: Shape near quadrate with some punctures concentrate near sides; disc concave with sparse punctures in male; head less concave and more punctate in female; punctures moderate; as wide as one elytra width. Canthi rounded, protruding into the first third of the eye. Labrum strongly transverse with three processes anteriorly and with transverse setae at the middle in male; labrum less transverse in female, lateral processes lacking and middle of anterior margin weakly projected with two small transverse concavities on disc. Mandible of males symmetrical with apex simple (not bifurcate); internally with strong bifid basal tooth, with elevated “v” shaped process above; inner margin concave distally with 1–2 small, obtuse teeth. Mandibles projected inward in females, shorter than head and with 1 acute inner tooth. Maxillae with lacinia and galea subequal in length; lacinia with a hook like apex slightly curved inside; second palpifer with an elevated process (male); female with lacinia shorter than galea and with abrupt incurved hook like apex; galea with two backward curved hooklets. Pronotum: Sides rounded to subparallel, anteromedially with two rounded tubercles in males, females with pronotum unarmed, simply convex. Disc smooth, sparsely punctate; punctures fine in males, fine to moderate in females. Surface basally with row of large, elongate punctures before basal margin in both sexes. Elytra: Form overall elongate, flattened, slightly convex dorsally. Surface entirely, densely punctate; punctures varying in size and density, near suture with sparse, fine punctures to coarse, large punctures basally on disc. Legs: Protibiae with 4–8 external teeth; spur with apex curved down. Mesotibiae with 3 external teeth, 2 smaller proximally and 1 near the apex. Metatibiae with one external median tooth. Male genitalia: Genital capsule simple, without additional lobes or projections; form elongate, with emarginated posterior margin of dorsal plate. Basal piece ventrally convex; internal margin converging inside abruptly; dorsally with two inwards projections. Aedeagus (Fig. 5) symmetrical, median lobe not reaching apex of parameres, anteriorly emarginate just before its longitudinal half and posteriorly bifurcated into two elongate projections. Everted internal sac (Fig. 5a) setose with short setae laterally, abruptly expanded in basal fifth, expansions rounded.

Distribution. Brazil: Rio de Janeiro: Itatiaia.

Type material. Of the four syntypes mentioned by Boileau in the MNHN for S. aurocinctus , only two were located. Lectotype male at MNHN with label data: a) red-bordered label, “ TYPE ”; b) white, blackbordered label, “ BRÉSIL / ÉT DE RIO DE JANEIRO / ITATIAYA 2400 / E. GOUNELLE. 2-99”; c) white, black-bordered label, “ Type ”; d) white, handwritten label, “ Sclerostomus / aurocinctus / Boil”; e) red label, Sclerostomus / aurocinctus / Boileau, 1899 / LECTOTYPE / det. MJ PAULSEN 2008. LECTOTYPE HERE DESIGNATED. Paralectotype female with label data ( MNHN): a) white label, “ex coll. / Boileau”; b) red label, “ TYPE ”; c) white, handwritten label, front, “Itatiaya / 2300 m ”, back, “N’ Gounelle / 1899”; d) red label, Sclerostomus / aurocinctus / Boileau, 1899 / PARALECTOTYPE’ / det. MJ PAULSEN 2008.

Type material of Sclerostomus marginivillosus Lüderwaldt, 1935 . Seven syntypes were listed in the original series. Two syntypes are missing from the visited collections, a male and a female. The 5 specimens studied are labeled as follows. One syntype male with label data ( MZSP): a) male symbol; b) red label with black border, “COTIPO”; c) “E. do Rio / Itatiaya – 2200 m ” / handwritten “Alto” / “Est. Biologica” / handwritten “ 1-VII-1933 ”; d) black-bordered, handwritten, “Sclerost. (male symbol) / marginivillosus / Lüder. / Lüder. det 33.”; e) handwritten, “= aurocinctus BOILEAU / compared with the / type (Mus. Paris) / Weinreich det. 1959”; f) “08832”. One female syntype with label data ( MZSP): a) female symbol; b) red label “cotipo”; c) “E. do Rio / Itatiaya – 2200 m ” / handwritten “Alto” / “Est. Biologica” / handwritten “ 18-VI- 1933 ”. One syntype male with label data ( MNRJ): a) male symbol; b) “E. do Rio/ Itatiaya – 2200 m ” / handwritten “Alto” / “Est. Biologica” / handwritten “ 1-VII-1933 ”; c) pink, interrupted black border “ TYPUS ”; d) black-bordered, handwritten “Sclerost. (male symbol) / marginivillosus / Lüder. / Lüder. det 33.”; d) handwritten, “ Sclerostomus / marginivillosus , / Ldw.”. One syntype male with label data ( FIOC): a) male symbol; b) “E. do Rio/ Itatiaya – 2200 m ” / handwritten “Alto” / “Est. Biologica” / handwritten “ 1-VII- 1933 ”; c) pink, interrupted black border “ TYPUS ”; d) black-bordered, handwritten “Sclerost. (male symbol) / marginivillosus / Lüder. / Lüder. det 33.”; e) handwritten, “ Sclerostomus / marginivillosus , / Ldw.”, f) “Coleção / J. F. Zikan”, g) “Nº 7.585 / I.O.C. Coleoptera ”. One syntype female with label data ( FIOC): a) female symbol; b) “E. do Rio / Itatiaya – 2200 m ” / handwritten “Alto” / “Est. Biologica” / handwritten “ 22- VII-1933 ”; c) pink, interrupted black border “ TYPUS ”; d) black-bordered, handwritten “Sclerost. (female symbol) / marginivillosus / Lüder. / Lüder. det 33.”; e) handwritten “ Sclerostomus / marginivillosus , / Ldw.”, f) “Coleção / J. F. Zikan”, g) “Nº 7.584 / I.O.C. Coleoptera ”.

Additional material studied: One male with label data ( FIOC): Rio de Janeiro, Itatiaia, 30-VI-1933, 2200 m; two males with label data ( MNRJ): Rio de Janeiro, Itatiaia, without other data; one male with label data ( MTD): Rio de Janeiro, Itatiaia, II-1899, 2400, E. Gounelle.

Diagnosis. Body elongate, slightly convex dorsally (Fig. 11). Pronotum in males with two median anterior tubercles, tubercles lacking in female; a transverse row of elongate punctures present basally in both sexes. Elytra in both sexes entirely punctate, basally with punctures coalescent; internal surface of each puncture reticulated. Elytral lateral margin with band of long, yellow setae.

Remarks. This species was first described by Boileau in 1899 from four specimens deposited in the MNHN. Lüderwaldt (1935) described Sclerostomus marginivillosus based on four males and three females, a pair in MZSP and the others at Zikán collection (now in FIOC and MNRJ). In this study we examined the material from these collections and observed six males and two females of S. marginivillosus . Weinreich (1958, 1960, 1963) revised the South American lucanids and in 1960 placed S. marginivillosus as a junior synonym of S. aurocinctus and transferred S. aurocinctus and another three species to the subgenus Altitatiayus .

By studying the external morphology and genitalia we concluded that this species forms a monotypic genus with diagnostic characters that make it possible to distinguish it from all other South American genera. The elytral vestiture consists of a marginal band of long setae, a character that is almost unique among South American lucanids, and the convex pronotum has a band of longitudinally elongate punctures along the base.

The simple form of the male genitalic capsule makes it clear that this species has been misplaced in Sclerostomus . The species further differs from Sclerostomus sensu stricto in lacking a pronotal median depression, and having the elytra completely, irregularly punctate without striae or carinate intervals, and with the punctures strong and reticulated internally. Species of Altitatiayus have the mandibles in males with apices at least with one bifurcation, pronotum in males without anterior tubercles, elytral punctures confined to rows, punctures of the integument smooth, and the elytral margin glabrous. The male genitalia of Zikanius aurocinctus are more similar to those found in species of Apterodorcus , Pycnosiphorus , and Chileistomus . In addition to the unique elytral vestiture and elongate basal pronotal punctation, this species differs from those genera in the possession of a paired tubercle on the anterior margin of the pronotum in males.

This species probably has a very restricted habitat because all specimens examined have come from Itatiaia at elevations over 2000 m. Also, as in Altitatiayus , Zikanius aurocinctus is brachypterous and does not have good dispersal capacity. Since the 1930s, no additional specimens have been collected, and the exact locality is unknown. The best available data indicates ‘Itatiaia’ at 2300 m. This could refer to many localities in the Itatiaia Plateau, an extremely vast region with elevations varying from 700 m to about 2790 m.

Nothing is known about the biology of this species, but given its brachyptery, it is possible that its life history is similar to that of Altitatiayus ruficollis . As described by Nagel (1934), the larvae were found feeding in a mixture of soil, mosses, and lichens. This also happens with some montane lucanids of the Andean genus Sphaenognathus Buquet ( Onore 1994) , and the genera Amneidus Coquerel and Agnus Burmeister on Réunion ( Paulian 1957, 1973).