Sclerocoelus cubus Kuwahara, Marshall & Paiero, 2025, sp. nov.
Creators: name: Kuwahara, Gregory K.
name: Marshall, Stephen A.
name: Paiero, Steven M.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Sphaeroceridae
Sclerocoelus
Sclerocoelus cubus

description: Sclerocoelus cubus sp. nov.
urn:lsid:zoobank.org:act: E907D635-A5B2-42BD-9B40-5A9B6BBB836A
Figs 6B, 40–41
Etymology
This name (from the Latin ‘ cubus ’, meaning ‘cube’) refers to the very distinctive cube-shaped male epandrium.
Material examined
Holotype
ECUADOR • ♂; Pichincha, Cotopaxi National Park, Quebrada Mishahuaycu; 3600 m a.s.l.; 26 Oct.–8 Nov. 1999; S.A. Marshall leg.; along stream, pan traps; QCAZ debu00139226.
Paratypes
ECUADOR – Carchi • 1 ♂; Bosque El Arrayán, 6 km E of San Gabriel; 2830 m a.s.l.; 1 Nov. 1999; S.A. Marshall leg.; sweeping; DEBU • 1 ♂; same data as for preceding; 2–4 Nov. 1999; forest, dung traps; QCAZ • 1 ♂; Páramo El Angel, 14.1 km NW of El Angel; 3450 m a.s.l.; 1 Nov. 1999; S.A. Marshall leg.; under Polylepis litter; QCAZ. – Pichincha • 2 ♂♂; same data as for holotype; DEBU • 1 ♂; Lago Limpiopungo; 3800 m a.s.l.; 25 Oct. 1999; S.A. Marshall leg.; lake edge, pans near cow dung; DEBU • 3 ♂♂; Valley near Hostería San Jorge, 10 km NW of Quito; 3000 m a.s.l.; 23 Oct. 1999; S.A. Marshall leg.; pans in grass pile; QCAZ.
PERU – Cusco • 1 ♂; 6.6 km S of Paucartambo; 13°22′49″ S, 71°36′17″ W; 3400 m a.s.l.; 13–16 May 2007; Marshall, Kits and Paiero leg.; along creek, yellow pans; MUSM.
Description
BODY (Fig. 40A). Length 2.6–3.4 mm. Head dark brown, ventrolateral corners of frons reddish. Frontal width 2.2–2.3× frontal height. Three pairs of strong interfrontal bristles surmounting a very fine fourth pair; anterior orbital 0.5–0.6 × length of posterior. Palpus yellow. Eye large, greatest height about 3.5× shortest genal height. Thorax dark brown, scutum with slightly paler lateral edges. Two pairs of dorsocentral bristles (anterior pair distinct, 0.5 × length of posterior pair) separated by 7–8 rows of acrostichal setulae. Membrane around prosternum bare. Legs brown, hind tibia darker. Fore femur with five large ventral preapical setae. Dorsal surface of mid tibia with an offset pair of setae at about ⅓, a large anterior seta at about ½, and a pair of large setae at about 4/5. Ventral surface of male mid tibia with two rows of stout setae along apical half. Wing (Fig. 6B) slightly infuscate. CS2 0.8–0.9× CS3. Halter brown.
MALE ABDOMEN (Figs 40B–C, 41). Dark brown, posterior edges of tergites sometimes slightly desclerotized. T2–5 and S2–4 uniformly long-setose with large posterolateral setae. S5 large, deeply emarginate anteromedially, laterally long-setose, huge flattened posteromedial area filled with blunt, peg-like setae and some scattered longer setae, anteromedial-most peg seta in an eye-like depression. Anterior flange of S6+7 large, triangular, 1.2× as long as wide. Sclerite A pale, rounded, fused to S6+7; sclerite B dark, elongate, arched inwards and basally fused to sclerite A; sclerite C apparently absent; sclerite D dark, triangular, projecting dorsally; sclerites E and F fused, very large, dark, sheet-like; sclerite G reduced; ring sclerite small but well sclerotized. S8 large, flattened dorsally. Epandrium small, boxy (dorsal, lateral, and posterior surfaces almost at right angles to each other), 0.5× length of S8, height 1.7× maximum length and 0.7× maximum width, long-setose; anal fissure very large, circular; perianal pads weakly developed. Pseudocercus absent; halves of subepandrial sclerite arched, medially fused. Subcercus large, wedge-shaped, triangular in posterior view, sinuate rectangular in lateral view, apex deeply bifid (similar in appearance to a very high-heeled shoe/boot), outer-posterior lobe expanded with three inner setae, inner-anterior lobe tapered and curved with some sensory setulae. Hypandrium with slightly sinuate anteromedial apodeme. Surstylus C-shaped, anterior lobe smaller, angled inwards with several inner setulae, posterior lobe much larger and curved outwards. Postgonite elongate, gently tapered, basal third with a short, triangular, anterior lobe, apical third slightly bent forward. Phallapodeme very large, dark, curved; basiphallus large, stout basally and constricted apically with a small, nodelike anterodorsal ejaculatory apodeme; distiphallus strongly sinuate, largely membranous with a pair of strong, sinuate ventrolateral sclerites, anterior surface of membrane densely spiculose.
FEMALE ABDOMEN. Female unknown.
Distribution
Neotropical: Ecuador, Peru.
Remarks
Sclerocoelus cubus sp. nov. is superficially similar to S. frigidifrons sp. nov., from which it can be separated by the slightly smaller size (2.6–3.4 mm), larger eye (~3.5 × genal height), and very characteristic male genitalia. Like other basal species of the genus, Sclerocoelus cubus is a high Andean species associated with wet, green litter, generally above 3000 m a.s.l.
description: Published as part of Kuwahara, Gregory K., Marshall, Stephen A. & Paiero, Steven M., 2025, A revision of the genus Sclerocoelus Marshall (Diptera: Sphaeroceridae), pp. 1-277 in European Journal of Taxonomy 979 on pages 47-48, DOI: 10.5852/ejt.2025.979.2803, http://zenodo.org/record/14980852