Sclerocoelus ocellatus 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 ocellatus

description: Sclerocoelus ocellatus sp. nov.
urn:lsid:zoobank.org:act: 6EB0AB11-D632-4787-B09F-A3C6886FD2DC
Figs 8C, 99–101
Etymology
This name refers to the greatly reduced eye of this species, smaller than that of any other species of Sclerocoelus (from the Latin ‘ ocellatus ’, meaning ‘having small eyes’).
Material examined
Holotype
COSTA RICA • ♂; San José, Cerro de la Muerte, 20 km S of Empalme; 2800 m a.s.l.; Nov.–Dec. 1989; P. Hanson leg.; MNCR.
Paratypes
COSTA RICA – Cartago • 1 ♀; Highway 2, km 95; 9°36′ N, 83°44′ W; 3200 m a.s.l.; 1–7 Jun. 1985; H. Goulet and L. Masner leg.; DEBU. – San José • 1 ♀; same data as for holotype; MNCR.
Description
BODY (Fig. 99A). Length 2.9–4.0 mm. Head dark brown, very bottom of frons orange; anterior half of gena orangish. Frontal width 2.2–2.3× frontal height. Three pairs of strong interfrontal bristles surmounting a fine fourth pair; anterior orbital 0.6× length of posterior. Palpus brown. Eye small, greatest height about 1.1–1.3 × shortest genal height. Thorax dark brown, scutum with paler lateral edges. Two pairs of dorsocentral bristles (anterior pair distinct, 0.6× length of posterior pair) separated by 6–7 rows of acrostichal setulae. Membrane around prosternum bare. Legs brown, mid femur slightly darker. Fore femur with four large ventral preapical setae. Wing (Fig. 8C) infuscate. CS2 subequal to CS3. Halter brown.
MALE ABDOMEN (Figs 99B–C, 100). Dark brown, posterior edges of tergites sometimes slightly desclerotized. T2–5 and S2–4 uniformly long-setose with large posterolateral setae. S5 rectangular, 1.2× length of S4, sparely setose with a dark, elongate, posteromedial patch of dense setulae flanked by long-setose, pale patches. Anterior flange of S6+7 rectangular, 1.0 × as long as wide. Sclerite A pale, setulose, and weakly fused to S6+7; sclerite B dark and strongly arched into genital pouch; sclerite C apparently absent; sclerite D dark, elongate, expanded where it articulates with left side of posteromedial lobe of S5; sclerite E dark, elongate, closely associated with sclerite D, together forming a V-shaped; sclerites F and G fused, sclerite F with an elongate posteroapical process on left side, sclerite G bulbous and setulose; ring sclerite well developed but thin. Epandrium moderate, 0.6× length of S8, height 1.4× maximum length and 0.8× maximum width, uniformly long-setose; perianal pads bulging but membranous. Pseudocercus small, fused to posterolateral corner of epandrium and overlapping base of subcercus, bearing 3 setae; halves of subepandrial sclerite strongly arched with inner arch broadened. Subcercus large, setulose, flattened posteriorly with a triangular posteroventral lobe curving inwards. Hypandrium with sinuate, evenly tapered anteromedial apodeme. Surstylus large, 1.4 × as long as deep, bulbous, long-setose along inner surface with a small, triangular, inner anterobasal lobe. Postgonite short, sinuate, apically truncate with a slight constriction about midlength and a small, tooth-like, preapical anterior lobe. Phallapodeme large, slightly sinuate, with apex dorsoventrally flattened; basiphallus large, curved with an elongate, beak-like epiphallus and expanded distally along dorsal margin of distiphallus; distiphallus short, largely membranous with an elongate dorsal sclerite and a pair of short lateral sclerites.
FEMALE ABDOMEN (Fig. 101). T7 broad, simple; T8 divided into a large, pale, dorsal sclerite and two large, dark, lateral sclerites, posterolateral corners expanded and pointed. Epiproct large, subtriangular, entirely sparsely setulose with an additional posteromedial seta near posterior margin. Cercus elongate, apically rounded with long apical and dorsal setae. S7 broad, broadly desclerotized posteriorly and medially with four large posterior setae; S8 entirely membranous. Hypoproct with entirely densely setulae. Three spermathecae, bulb stout, subspherical, finely striate with shallow basal and subapical invaginations, both with a small, finger-like, central process.
Distribution
Neotropical: Costa Rica.
Remarks
Sclerocoelus ocellatus sp. nov. is easily distinguished from all other species of Sclerocoelus by its small eye (1.1–1.3× genal height). Sclerocoelus ocellatus is known from a few specimens collected in high elevation forests in the mountains south of San Jose, Costa Rica. It is one of four endemic Costa Rican Sclerocoelus species and one of the seven members of the S. dasysternum group found in Costa Rica.
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 84-85, DOI: 10.5852/ejt.2025.979.2803, http://zenodo.org/record/14980852