Leucothyreus noctivagus Ohaus, 1917

Bento, Matheus, Grossi, Paschoal, Ruy Vasconcelos da Fonseca, Claudio & Seidel, Matthias, 2025, Reassessment of Leucothyreus noctivagus Ohaus, 1917 reveals Mimogeniates margaridae Martínez, 1964 as new generic and specific synonym (Scarabaeidae, Rutelinae, Geniatini), ZooKeys 1264, pp. 61-71 : 61-71

Leucothyreus noctivagus Ohaus, 1917

Leucothyreus noctivagus Ohaus, 1917: 15 [original combination]; Blackwelder 1944: 249; Machatschke 1974: 409; Jameson and Hawkins 2005: 45; Krajcik 2007: 77.

Mimogeniates margaridae Martínez, 1964: 5 [original combination]; Machatschke 1972: 359; Jameson and Hawkins 2005: 24, 53, 65, 70; Krajcik 2007: 89. Syn. nov.

Type material examined.

Leucothyreus noctivagus : lectotype • male (here designated) deposited at MFNB (Fig. 1 A – D ), labeled: “ Espírito Santo / Sta. Leopoldina / O. Michaelis ” (white, printed) // “ berlin ” (white, printed in red) // “ Cotype ” (red, printed) // “ Leucothyreus / noctivagus Ohs. ” (red, printed) // “ SYNTYPUS / Leucothyreus / noctivagus Ohaus, 1817 / labeled by MNHUB 2016 ” (red, printed) . Paralectotypes, • same data as lectotype ( ♂, MFNB) ; • same, but “ Boa Sorte / F. Sahlb. ” (white, printed) // “ ♀ ” ( ♀, MFNB) ; • same, but “ Rio Itapemirim / E. Esp. S. – Brazil / 5-12 - 1908 / J. F. Zikán ” (white, printed) ( ♀, MFNB) ; • same, but “ Petropolis / 15. I. 99 / Electr. Licht ” (white, printed) ( ♀, MFNB) ; • same but “ Minas Gerais / Mar d. Espanha / J. Zikán S. ” (white, printed) // “ 14 / 11 / 1909 ” (white, handwritten) ( ♀, MFNB) . Mimogeniates margaridae : Paratype • female deposited at CMN, labeled: “ BRASIL. E. Santo / Linhares Sooretama / NOV. 62 A. Martínez ” (white, printed) // “ PARATIPO ” (green, printed) // “ Mimogeniates / margaridae / ♀ sp. n. / Martinez-det, 1964 ” (light green, handwritten) // “ H. & A. HOWDEN / COLLECTION / ex. A. Martinez coll. ” (white, printed) .

Additional material ( 17 males; 17 females).

Brazil • Rio de Janeiro, Bom Jardim, Sítio São José , 29.xi.2003, M. Hoffmann col. ( ♂, CERPE) ; Brazil • São Paulo, Itú, Fazenda Pau d’Alho , 28–29.X.1965, Martins & Biasi (legs.) ( ♂, NMB) ; Brazil • Espírito Santo, Itapemirim , 5.XII.1908, J. F. Zikán (leg.) ( ♀, CEIOC) ; Brazil • Espírito Santo, Linhares, Parque Sooretama , 17–27.X.1962 ( ♂, CMN) ; Brazil • Espírito Santo, Rio Bonito , XI.1963, A. Maller (leg.), Martínez collection ( ♂, CMN) ; Brazil, Espírito Santo, Linhares, Flona de Goytacazes , 19°25'56.3"S, 40°04'12.6"W, 27.xi.2010, light, DS Martins ( ♂, ♀, CERPE) ; • same, but 09.xi.2010 ( 2 ♂, 3 ♀, CERPE) ; • same, but 19.xi.2010 ( 2 ♀, CERPE) ; Brazil • Bahia, Encruzilhada , XII.1980, A. Martínez & M. Alvarenga (legs.) ( ♀, CMN) ; Brazil • Minas Gerais, Pedra Azul , 1974 ( ♀, NMB) ; Brazil • Minas Gerais, Mar de Hespanha , 19.XI.1909, J. F. Zikán (leg.) ( ♀, CEIOC) ; Brazil • Minas Gerais, Ipatinga , xi.1989, luz, E. & P. Grossi legs. ( 5 ♂, 6 ♀, CERPE) ; Brazil • Minas Gerais, Itumirim , 23.3400°S, 44.6016°W, x.2016, FZ Vaz-de-Mello ( ♂, CERPE) ; Brazil • Minas Gerais, Lavras , 02.vii.2007, PF Espuri ( ♂, CERPE) ; Brazil • Minas Gerais, Berizal, Faz. Veredão , 14.xii.2007, 850 m, Grossi, Rafael & Parizotto legs. ( 2 ♂, ♀, CERPE) ; Brazil • Minas Gerais, Águas Vermelhas , 13.xii.2007, Grossi, Rafael & Parizotto legs. ( ♂, CERPE) .

Diagnosis.

Labrum and prementum without medioapical projection (Fig. 3 D 1, D 4 ). Apical margin of prementum crenulated (Fig. 3 D 4 ). Outer margin of metafemur coarsely crenulated, with each crenulation bearing a short, white seta (Fig. 3 B ). Outer margin of meso- and metatibia with two short, spine-like projections (Fig. 3 A, B ).

Differential diagnosis.

This species is similar to L. kirbyanus MacLeay, 1819 (see Jameson and Hawkins 2005: fig. 7), as both share a similar general appearance of head and clypeus, chaetotaxy, similar form of the male aedeagus, coarsely crenulated outer margin of metafemur (Fig. 3 B ) as well as the outer margin of meso- and metatibia with short, spine-like projections (Fig. 3 A, B ). However, L. noctivagus is easily distinguished from L. kirbyanus and other species in the genus by the form of the prementum, which is crenulated and lacking a median projection (Fig. 3 A, B ).

Description.

Male (Figs 1 A – D , 2 A – D ). Length 9.5–10.5 mm. Width 4.8–5.3 mm. Body oval, elongate. Coloration of head, pronotum, and scutellar shield reddish brown, with weak to strong metallic-green reflections (Figs 1 A , 2 A, B ); head darker than pronotum. Elytra and legs light brown, with weak greenish reflections. Venter reddish brown, covered with white, scale-like setae. Pubescence: lateral surface of pronotum and scutellar shield moderately and irregularly covered with posteriorly decumbent, white, scale-like setae; setae thinner on scutellar shield; thoracic venter and abdomen densely covered with decumbent, white, scale-like setae. Head small, shorter than pronotum at middle, with deep, large, densely distributed punctures. Frons as wide as clypeus at base. Frontoclypeal suture complete and slightly sinuous at middle. Clypeus subrectangular, with anterior margin weakly raised. Labrum large, subtriangular, slightly longer than ventral face of clypeus; apex weakly angulated, not projected (Fig. 3 D 1 . Labium (Fig. 3 D 4 ) subrectangular, slightly wider than long; prementum with apical margin coarsely crenulated at middle, not projected; mentum with a transverse, moderate setal brush medially erect and laterally decumbent bearing thick, white setae. Labial palp 3 - segmented, with palpomere II distinctly shorter than III. Maxilla densely setose, with thick, decumbent, white setae; palpifer with outer margin strongly curved at base; maxillary palp 4 - segmented, with distal palpomere fusiform, longer than palpomere I – III combined, with a small, fusiform dorsal sensory area; galea (Fig. 3 D 3 ) apically large, with two acute teeth. Mandible externally rounded and weakly raised at apex; apical tooth rounded and slightly deflected ventrally; outer face with thick, white setae. Antennae with 10 antennomeres, with club elongate, slightly shorter than antennomeres 2–7 combined. Pronotum widest at middle; medially wider than head, with lateral margins evenly curved. Surface moderately covered with deep, setigerous punctures; lateral punctures with decumbent, scale-like, white setae. Anterior bead punctate, barely defined at middle; posterior bead complete and well defined. Anterior angles acute; posterior angles obtuse. Scutellar shield small, as wide as long, with posterior margin acute; basal surface with sparse, deep, setigerous punctures bearing thick, decumbent, white setae. Elytra shallowly rugopunctate, with three barely defined longitudinal costae. Lateral margins glabrous. Pygidium subtriangular and strongly concave posteriorly; whole surface moderately covered with deep, transversely fusiform punctures bearing white, transversely decumbent scale-like setae; posteromedial region with a few thin, erect setae. Thoracic venter: prosternum, meso- and metaventrite, and metacoxae densely covered with decumbent, scale-like, white setae; posterior prosternal process triangular, with apex acute. Metaventrite with postcoxal line medially effaced, with a row of thinner, hair-like setae. Legs: protibia slender, slightly wider at apex, with three small, acute outer teeth; proximal tooth reduced and largely separated from medial and distal teeth; protarsomeres I – V (Figs 1 A, B , 2 A, B , 3 C ) dorsoventrally flattened and densely setose internally; protarsomere I small, slightly surpassing the apex of protibia; II – IV somewhat caliciform and as wide as long; V as long as protarsomeres III and IV combined. Protarsal claws small, shorter than protarsomere V; anterior protarsal claw slender and laterally flattened, with a horizontal, apical cleft; posterior claw simple and shorter than anterior claw. Meso- and metafemur with outer margin coarsely crenulated; each crenulation bearing a short, thin seta. Meso- and metatibia slightly constricted near apex, with outer margin bearing one short, spine-like processes adjacent to each transverse carina (Fig. 3 A, B ); surface moderately covered with thick, hair-like, white setae. Inner meso- and metatibial spur longer than respective tarsomere I. Meso- and metatarsomeres I – IV slightly flattened dorsoventrally and densely setose internally. Meso- and metatarsomere V cylindrical, sparsely setose internally, longer than respective tarsomeres II – IV combined, with a short, acute internobasal tooth. Meso- and metatarsal claws slender, in flexed position as long as respective tarsomere V; anterior claw slightly thicker, with apex narrowly cleft; posterior claw simple. Meso- and metatarsal empodium with two long, apically bifurcate setae. Abdomen densely covered with decumbent, scale-like, white setae. Ventrite 1 medially projected, with posterior postcoxal line posteriorly extending to posterior margin of ventrite 1 and bearing dense, hair-like setae. Ventrites 1–4 with wide laterolongitudinal carinae. Ventrite 6 with posterior margin weakly emarginate. Aedeagus (Figs 1 D , 2 C, D ): parameres small, about ½ length of tectum; prolongations subparallel and completely fused together to apex, with a median fusion line barely defined. Apex evenly rounded, as wide as or slightly wider than midpoint, with outer margins slightly converging. Inner surface bearing an internomedial row of setae.

Female (Fig. 3 A – C ). Length 11–11.5 mm. Width 5.8–6 mm. Females very similar to males but with body more robust, pronotum sparsely setose, protibial outer teeth stronger, pro- and mesotarsomeres moderately setose and narrower, and posterior margin of ventrite 6 evenly rounded, not emarginate.

Distribution (Fig. 4 ).

Brazil. Bahia: Encruzilhada (new state record). Espírito Santo: Linhares, Rio Bonito, Itapemirim, Santa Leopoldina. Rio de Janeiro: Petrópolis, Boa Sorte, Bom Jardim. Minas Gerais: Mar de Espanha, Águas Vermelhas, Berizal, Itumirim, Ipatinga, Lavras. São Paulo: Itú (new state record).

Figures

Figure 1. Lectotype male (here designated) of Leucothyreus noctivagus Ohaus, 1917. A. Dorsal view; B. Ventral view; C. Labels; D. Aedeagus in frontal and lateral views. Scale bars: 5 mm (A, B); 1 mm (D).

Figure 2. Male of Leucothyreus noctivagus Ohaus, 1917. A. Dorsal view; B. Head and pronotum showing color variation with weak metallic-green reflections; C. Parameres in frontal view; D. Aedeagus in lateral view. Scale bars 5 mm (A); 1 mm (B); 0.2 mm (C). Photos by Vitor Nardino.

Figure 3. Paralectotype female of Leucothyreus noctivagus Ohaus, 1917. A. Dorsal view. B. Ventral view; C. Pronotum, head, and anterior legs of (left) female and (right) male; D. Mouthparts: D 1. Labrum showing lack of apical projection; D 2. Left mandible; D 3. Left maxilla; D 4. Labium showing crenulate apex. Scale bars: 5 mm (A, B); 1 mm (D).

Figure 4. Distribution of Leucothyreus noctivagus Ohaus, 1917.