Aegidiellus alatus (Castelnau)

Frolov, Andrey V., Akhmetova, Lilia A. & Vaz-de-Mello, Fernando Z., 2017, Revision of the Neotropical scarab beetle genus Aegidiellus Paulian (Coleoptera: Scarabaeidae: Orphninae) with description of two new species, Journal of Natural History (J. Nat. Hist.) 51 (29 - 30), pp. 1767-1779 : 1774-1776

Aegidiellus alatus (Castelnau)

( Figures 2 (a–f) and 3(a–e))

Phileurus alatus Castelnau 1840: 116 .

Aegidium alatum: Arrow 1912: 31 ; Gemminger and Harold 1869: 1073; Preudhomme de Borre 1886: 24; Schmidt 1913: 70; Vulcano et al. 1966: 255;

Aegidiellus alatus: Paulian 1984: 86 ; Colby 2009: 5; Frolov 2012: 796.

Aegidium haedulus Westwood 1845: 174 , synonymy by Gemminger & Harold 1869: 1073; Preudhomme de Borre 1886: 24 (as synonym of Aegidium alatus ).

Aegidium haedulum Westwood : Arrow 1912: 31 (as synonym of Aegidium alatum ); Schmidt 1913: 70 (as synonym of Aegidium alatum ).

Type locality

Brazil.

Type material examined

Neotype of Phileurus alatus (here designated according to ICZN article 75, see remarks below) and lectotype of Aegidium haedulum (here designated according to ICZN article 74, see remarks below): male at OUMNH labelled ‘ Aegidium haedulus Dej. Brasil /type of Aegidium haedulum haedulum Westw. /Type Westwood Trans. Ent. Soc. 1846. p. 174. Coll. Hope Oxon /TYPE COL: 485 Aegidium haedulum Westw. HOPE DEPT. OXFORD /LECTOTYPUS Aegidium haedulus West. Frolov et al. 2016 /NEOTYPUS Phileurus alatus Cast. Frolov et al. 2016 ’.

Additional material examined

BRAZIL. Espírito Santo: Córrego Itá , I.1956, W. Grossmann leg., one male ( CMNC). Bahia: Santo Antonio da Barra, Salvador, XI-XII.1888, Gounelle leg., one male ( MNHN). Minas Gerais: Doce River Valley , XII.1957, P. Coelho leg., one male ( CMNC). Rio de Janeiro: Floresta da Tijuca , 6.I.1977, J. Celso leg., one male and one female ( CEMT); Araruama , III.1984, P. Arnaud leg., four males and four females ( CEMT); Ponta da Trindade , I.2004, E. D.F. Grossi leg., one male and one female ( CEMT); Pico do Corcovado, Guanabara , XII.1965, Alvarenga and Seabra leg., one male ( CEMT); Rio de Janeiro, one female ( BMNH); Newton Santos leg., one male ( MNRJ); Rio de Janeiro, Corcovado, XI.1962, Martinez leg., one male ( CMNC); XII.1958, Martinez, Alvarenga and Seabra leg., one female ( CMNC); 19.XII.1958, D. Zajciw leg., one female ( MNRJ). Brazil (without precise locality), one male ( ZIN), one male and one female ( MHNG), one male and two females ( BMNH), two males and one female ( MNHN), one male and one female ( NMPC), one male ( IRSNB); Steinheil leg., one female ( IRSNB); Deyrolle leg., one male and one female ( IRSNB). No locality, two males ( BMNH), two males and one female ( MNHN).

Diagnosis

Aegidiellus alatus is most similar to A. zezaoi sp. nov. but can be separated from it by the parameres less tapering apically and with wider apices ( Figures 2 (e) and 3(d)); dorsal side of parameres straight to slightly sinuate in lateral view ( Figures 2 (d) and 3(c)).

Description

Male ( Figure 3 (a)). Anterior margin of frontoclypeus slightly convex in middle, slightly sinuate each side of medial convexity, rounded laterally, with a narrow border. Frontoclypeus relatively densely punctate anteriorly and sparsely punctate to smooth posteriorly; posterior part of frontoclypeus mostly hidden under protruding anterior margin of pronotum.

Pronotum with widely rounded lateral margins, as wide as elytra, 1.5 times wider than length, 0.6 times length of elytra. Posterior angles slightly sinuate in dorsal view. Anterior margin bordered laterally, trapezoidal, protruding anteriorly to cover most of posterior part of frontoclypeus, with a conical tubercle-like anterior pronotal process. Base of pronotum without furrow, punctate with irregular row of round to strongly elongated punctures, interrupted medially. Pronotum deeply excavated in middle, almost flat on disc. Disc punctate with coarse, rounded punctures separated by one to two puncture diameters except for sparsely punctate area in near base.

Elytra 1.08 times longer than wide, with feebly distinct humeral and apical humps. Elytra widest in basal one-third, rounded apically in dorsal view. Elytral carinae marked with rows of round to elongated punctures separated by three to five times their diameters on disc, becoming denser laterally and apically. Sutural stria as furrow in apical half. Elytral intervals smooth.

Aedeagus with relatively slender phallobase, separated into smaller basal and larger apical parts by constriction ( Figures 2 (d)and 3(c)). Apical part of phallobase with protruding anterodorsal margin and without convexity anteroventrally. Lateral margin of parameres without sinuation. Apices wide and feebly tapering apically ( Figures 2 (e) and 3(d)). Spiculum gastrale triangular ( Figure 3 (e)).

Female ( Figure 3 (b)). differs from male in having a long protibial spur, relatively smaller pronotum feebly sinuate medially on disc, anterior margin of pronotum not protruding, and anterior pronotal process small and tubercle-shaped.

Variation

Body length of males 9.1–11.0, females 8.5–10.0. Pronotal armature of males varies: some specimens have less developed lateral pronotal processes, shallower excavation on disc, and rounded anterior margin with smaller anterior pronotal process, similar to that in females.

Distribution

The species is known from a number of localities spanning from Ponta da Trindade in the south to Salvador in the north ( Figure 2 (f)). Most of the localities are situated in coastal areas.

Remarks

Phileurus alatus was described from ‘Brazil’ without more exact locality and indication of the number of specimens examined ( Castelnau 1840). A few years later Westwood (1845) described Aegidium haedulus . In the catalogue by Gemminger and Harold (1869) and all subsequent literature, Aegidium haedulus was considered a junior synonym of Phileurus alatus . The type of the Castelnau’ s species is apparently lost. It is not mentioned in any literature and Paulian, who had probably looked for it for his revision of the New World Orphninae ( Paulian 1984) , noted that the type was unknown to him. Despite our extensive search in all major collections no Aegidellus specimens that might originate from Castelnau’ s collection were found. Castelnau’ s collection that probably included the type was donated to the National Institution, Washington DC, USA, in 1842 and later turned over to the Smithsonian Institution. The collecion was apparently destroyed in the fire at the Smithsonian Institution in 1865 ( Evenhuis 2012).

The brief diagnosis of Phileurus alatus agrees with all three currently recognized Aegidiellus species. Therefore the apparent loss of the type compromises stability of the nomenclature of the genus and makes the neotype designation necessary. Because Aegidium haedulus was never used as a valid name since its synonymy with Phileurus alatus was established and because the syntype of the former, housed in OUMNH, is a well-preserved male specimen ( Figure 2 (a–e)) with all diagnostic characters of Aegidiellus alatus as it was understood by all authors, this specimen satisfies the criteria of the neotype designation (ICZN, article 75) and it is chosen as the only name-bearing specimen for Phileurus alatus . Because on the original description of Aegidium haedulus the exact number of the examined specimens was not indicated but both sexes were mentioned, we designate the same specimen as the lectotype of Aegidium haedulus , and, accordingly, establish an objective synonymy of the names.

Figures

Figure 2. Aegidiellus alatus¸ neotype, male. Habitus in dorsal (a) and lateral (b) view, labels (c), aedeagus in lateral view (d), parameres in dorsal view (e), locality map of A. alatus (f).

Figure 3. Aegidiellus alatus. Habitus of male (a) and female (b)¸ aedeagus in lateral view (c), parameres in dorsal view (d), spiculum gastrale (e).