Aegidium angustum Frolov, Akhmetova

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 : 1058-1061

Aegidium angustum Frolov, Akhmetova and Vaz-de-Mello, sp. nov.

( Figure 1 (a–g))

Type locality

Ecuador, Cotopaxi, Sigchos.

Type material examined

Holotype, male at MCGI labeled ‘ Ecuador Cotopaxi Amalliquin 2–1982 G. Onore’ ( Figure 1 (b)) . Paratype, female at CEMT labeled ‘ ECUADOR COTOPAXI PILALO I.87 Legit G. Onore’ .

Diagnosis

Ae. angustum sp. nov. can be separated from other continental members of Aegidium by its brachyptery and small eyes.

Description

Holotype, male ( Figure 1 (a,d–f)). Body length 12.0 mm. Colour uniformly blackish brown.

Anterior margin of frontoclypeus slightly undulate in dorsal view, rounded laterally, without border. Frontoclypeus densely punctate with rounded punctures separated by about 1 puncture diameter; punctures on basal part of frontoclypeus 1.5–2.0 times larger than in apical part.

Eyes small: width about 1/24 the distance between eyes in dorsal view.

Pronotum with widely rounded lateral margins, narrower than elytra, 1.3 times wider than length, 0.55 times length of elytra. Posterior angles rounded in dorsal view. Anterior margin not bordered. Base of pronotum without furrow, with a row of large, rounded, almost adjoining punctures. Pronotal disc flattened medioanteriorly, without lateral pronotal processes; anterior pronotal process as small rounded tubercle. Pronotum punctate with large rounded punctures separated by about 1 puncture diameter on disc and becoming denser towards anterior and posterior angles.

Scutellum subtriangular, rounded apically, about 1/16 length of elytra.

Elytra 1.25 times longer than wide, without humeral and apical umbones. Elytra widest in basal 1/3, slightly tapering apically in dorsal view. First elytral carina distinct basally, second indistinct. Elytra covered with relatively dense rounded to elongate punctures separated by about 1 puncture diameter.

Brachypterous, wing rudiments about 1/3 length of elytra.

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

Aedeagus with relatively long (0.55 times length of phallobase), tapering parameres ( Figure 1 (d)). Apices of parameres strongly sclerotised, widened in dorsal view. Parameres about as wide as apical part of phallobase in dorsal view ( Figure 1 (e)). Separate ventrobasal transverse plate of parameres indistinct. Endophallus without strongly sclerotised sclerites. Cranial part of spiculum gastrale relatively wide, slightly tapering, rounded but not widened apically ( Figure 1 (f)).

Female paratype ( Figure 1 (c)) differs from male in having protibial spur, and convex pronotum without flattened area and anterior pronotal process. Body length 12 mm.

Distribution

Aegidium angustum sp. nov. is known from two high-altitude localities on the slopes of Cotapaxi Volcano in the Ecuadorian Andes ( Figure 1 (g)).

Etymology

The name of the new species is from the Latin angustus for ‘narrow’, referring to the shape of the body.

Figures

Figure 1. Aegidium angustum, holotype male (a,b, d, e,f), paratype female (c). Habitus in dorsal view (a, c), labels (b), aedeagus in lateral view (d), parameres in dorsal view (e), spiculum gastrale (f), locality map (g).