Aegidium colombianum Westwood, 1845

Frolov, Andrey V., Akhmetova, Lilia A. & Vaz-de-Mello, Fernando Z., 2017, Revision of the mainland species of the Neotropical genus Aegidium Westwood (Coleoptera: Scarabaeidae: Orphninae), Journal of Natural History 51 (19 - 20), pp. 1035-1090 : 1061-1063

Aegidium colombianum Westwood, 1845

( Figures 2 (a–g) and 3(a–c))

Aegidium colombianum Westwood 1845: 174

Aegidium colombianum Westwood : Lacordaire 1856: 131; Gemminger and Harold 1869: 1073; Preudhomme de Borre 1886: 24; Bates, 1887: 105; Arrow, 1903: 515, 1904: 738, 1912: 31; Heyne and Taschenberg 1907: 72; Schmidt, 1913: 70; Paulian 1984:

Aegidium elongatum Paulian, 1984 , syn. nov.

Type locality

Colombia.

Type material examined

Aegidium columbianum : lectotype, here designated ( Figure 2 (a,d,e)): male at OUMNH labeled ‘ Aegidium Columbianum Westw. Trans. Ent. Soc. 4. P.174. Pl 12 Figures 7–8 Columbia/TYPE COL: 486 Aegidium columbianum Westw. HOPE DEPT.OXFORD /Co-TYPE WESTWOOD Trans. Ent. Soc. 4. 1864. P.174. T 12 f. 7–8/W’.

Aegidium elongatum : holotype ( Figure 3 (a–c)): male at BMNH labeled ‘Colombia 75–36/Columb./3922/Holotype/ Aegidium elongatum n.s. R.Paulian/HOLOTYPE’; paratype: female at MNHN labelled ‘ Aegidium columbianum West. Caracas/ Aegidium elongatum n. sp. R.Paulian det./ALLOTYPE/MUSEUM PARIS’.

Additional material examined

COLOMBIA: without precise locality, two males at BMNH, one male at IRSNB, two males at MHNG, nine males and three females at MNHN, one male and one female at OUMNH, two males and one female at RMNHL, two males at ZIN, four males and one female at ZMUKK . VENEZUELA. Distrito Capital: Caracas , one male at BMNH, one male and one female at CNCI, three males at MNHN, one female at OUMNH, one male at ZIN, three males and three females at ZMUKK; without precise locality, seven males and four females at BMNH, one female at IRSNB, one male and one female at MHNG, one male and one female at NHMB and one female at ZIN . BRAZIL: without precise locality, one male at ZIN, one male at IRSNB . NO LOCALITY: one male at BMNH, 14 males at MNHN and one male at OUMNH . CHILI: without precise locality, one male at BMNH (doubtful record) .

Diagnosis

Aegidium columbianum can be separated from other Aegidium species by the shape of the parameres ( Figures 2 (d,e) and 3(b,c)) and endophallic armature consisting of two strongly sclerotised hook-shaped sclerites and one asymmetrical y-shaped sclerite ( Figure 2 (b)).

Description

Male ( Figures 2 (a) and 3(a)). Body length 11.5–20.0 mm. Colour uniformly blackish brown.

Anterior margin of frontoclypeus slightly convex in middle, slightly sinuate each side of medial convexity, rounded laterally, without distinct border. Frontoclypeus punctate with rounded punctures separated by 1–2 puncture diameters.

Eyes relatively large: width about 1/7 distance between eyes in dorsal view.

Pronotum with widely rounded lateral margins, wider than elytra, 1.6 times wider than length, 0.55 times length of elytra. Posterior angles widely rounded, indistinct. Anterior margin bordered, border interrupted medially and not reaching anterior angles. Base of pronotum without furrow, punctate with a row of large, rounded, punctures separated by about 1 puncture diameter. Pronotal disc deeply excavated, with flattened area mediobasally. Lateral pronotal processes long, horn-shaped in lateral view, protruding past lateral margin outline of pronotum in dorsal view. Pronotum almost smooth: lateral processes almost impunctate, medial excavation punctate with sparse rounded punctures.

Scutellum narrow subtriangular, about 1/12 length of elytra.

Elytra 1.2 times longer than wide, with humeral and apical umbones. Elytra widest in basal 1/3, tapering apically in dorsal view. Elytral carinae weak, indistinct. Elytra covered with relatively sparse, rounded punctures separated by 2–3 puncture diameters at sides and somewhat denser, elongate punctures on disc.

Macropterous.

Mesotibiae without tuft of setae ventroapically. Inner apical spur of mesotibia shorter than basal mesotarsomere and not curved downwards.

Aedeagus with relatively long (0.66 times length of phallobase) parameres. Apices of parameres widened in dorsal view and curved downwards ( Figures 2 (d) and 3(b)). Parameres wider than apical part of phallobase in dorsal view. Ventrobasal transverse plate of parameres distinct. Lateral teeth of parameres large, strongly protruding past paramere outline in dorsal view ( Figures 2 (e) and 3(c)). Endophallus with 2 symmetrical, hook-shaped sclerites and 1 asymmetrical y-shaped sclerite ( Figure 2 (b)). Cranial part of spiculum gastrale relatively wide, slightly tapering, rounded to truncate apically ( Figure 2 (f)).

Female ( Figure 2 (c)) differs from male in having protibial spur, relatively smaller pronotum without armature, and in absence of inner protibial tooth. Body length 11.0–15.0 mm.

Variation

In addition to body size variability, males vary in the shape of the pronotum and its armature. In the material examined, there are specimens with a shallow excavation on pronotum medially and a small rounded anteromedial tubercle, and intermediate forms between it and specimens with fully developed pronotal armature.

Distribution

The distribution range of this species needs clarification. The specimens with exact locality data originated from Caracas, Venezuela. Most of the specimens, however, bear the label ‘Colombia’ or no locality label ( Figure 2 (g)). The record from Chile is doubtful.

Remarks

Paulian (1984) described Ae. elongatum based on the punctation of the mesepimera and elytra but he did not dissect the genitalia of the holotype. The characters of the punctation of the underside of the body vary and are largely not diagnostic. We dissected the aedeagus of the holotype and found that it has the characteristic shape of the parameres and endophallic hooks as in Ae. columbianum ( Figures 2 (a,b,d–f) and 3 (a–c)). The other characters also agree with the latter species, and we therefore propose the new synonymy.

Almost all the material of Ae. columbianum available to us was apparently collected in the nineteenth century. Only a few specimens were collected in the beginning of the twentieth century, and no recent records of this species are available.

Figures

Figure 2. Aegidium colombianum, lectotype male (a, d, e), female (c). Habitus in dorsal view (a, c), endophallus (b), aedeagus in lateral view (d), parameres in dorsal view (e), spiculum gastrale (f), locality map (g).

Figure 3. Aegidium colombianum, lectotype of Aegidium elongatum, male. Habitus in dorsal view (a), aedeagus in lateral view (b), parameres in dorsal view (c).

Figure 7. Aegidium rafaeli, holotype male (a, c, e–g), paratype female (d). Habitus in dorsal view (a, d), labels (b), apex of metatibiae (c), aedeagus in lateral view (e), parameres in dorsal view (f), spiculum gastrale (g), locality map (h).

Figure 8. Aegidium atlanticum, holotype male. Habitus in dorsal view (a), parameres in dorsal view (b), aedeagus in lateral view (c), apex of metatibiae (d), locality map (e).