Sclerocoelus dryadalis 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 dryadalis

description: Sclerocoelus dryadalis sp. nov.
urn:lsid:zoobank.org:act: 79EE3E5A-F45D-4EE8-BFAF-6A30EBAF78FD
Figs 6E, 47–49
Etymology
This name refers to the elfin forest in the type locality (from the Latin ‘ dryadalis ’, meaning ‘elf’).
Material examined
Holotype
VENEZUELA • ♂; Mérida, Sierra Nevada National Park, Laguna Negra; 4000 m a.s.l.; 28–30 Aug. 1992; L. Masner leg.; elfin forest, yellow pan traps; DEBU.
Paratypes
VENEZUELA – Mérida • 6 ♂♂, 8 ♀♀; same data as for holotype; DEBU • 1 ♂; Páramo de Mucuchies, Paseo de Aguila; 3740 m a.s.l.; 21 May 1998; R. Anderson leg.; dead leaves under Espeletia schultzi; DEBU.
Description
BODY (Fig. 47A). Length 3.1–4.9 mm. Head dark brown, ventrolateral corners of frons and gena orange-brown; face brown. Frontal width 2.3–2.4× frontal height. Three pairs of strong interfrontal bristles surmounting a fine fourth pair; anterior orbital 0.5–0.6× length of posterior. Palpus pale brown. Eye reduced, greatest height about 2.2× shortest genal height. Thorax brown, scutum with slightly paler lateral edges. Two pairs of dorsocentral bristles (anterior pair distinct, 0.4× length of posterior pair) separated by 6–7 rows of acrostichal setulae. Membrane around prosternum bare. Legs brown, hind femur paler. Fore femur with three large ventral preapical setae. Dorsal surface of mid tibia with three setae in proximal half (one small and one large anterior and one large posterior) and four setae in distal half (one small and one large anterior, one small dorsal, and one large posterior). Ventral surface of male mid tibia with two rows of stout setae along apical third. Wing (Fig. 6E) slightly infuscate. CS2 0.8–0.9 × CS3. Halter pale brown.
MALE ABDOMEN (Figs 47B–C, 48). Dark brown, posterior edges of tergites sometimes slightly desclerotized. T2–5 and S2–4 uniformly long-setose with large posterolateral setae. S5 broad, 0.8 × length of S4, uniformly long-setose, posterior margin pale with a heart-shaped darker posteromedial patch. Anterior flange of S6+7 not developed. Sclerite A bare, bulging ventrally from S6+7; sclerite B dark, arched into genital pouch; sclerite C apparently absent; sclerites D and E fused, dark, triangular with emarginate apex; sclerite F large, rounded with an elongate posterior apodeme on left side; sclerite G large, bulging; ring sclerite well developed, partially fused to posterior surface of sclerite G. Epandrium small, 0.4× length of S8, height 2.0× maximum length and 0.7× maximum width, densely setose; perianal pads weakly developed. Pseudocercus fused between epandrium and subcercus, bearing 3 setae; halves of subepandrial sclerite dark, only slightly curved and completely separated. Subcercus large, wedge-shaped, posterior surface with 3 setae, apical half expanded in lateral view, apex with a small posterior extension. Hypandrium with very thin anteromedial apodeme. Surstylus large, as tall as epandrium, leaf-shaped with a triangular anterobasal lobe, outer surface convex and densely setose, inner surface concave with some setae around edges. Postgonite elongate, relatively simple, gradually expanded, apical half with a shallow dorsal groove, apex truncate. Phallapodeme elongate, slightly sinuate; basiphallus elongate, slightly curved, expanded apically; distiphallus almost flower-shaped: basal half sclerotized and tubular, apical half largely membranous and flared outwards.
FEMALE ABDOMEN (Fig. 49). T7 broad, simple with two rows of setae, posterior setae longer; T8 divided into a pale, dorsal sclerite and two large, dark, lateral sclerites, posterolateral corners slightly expanded and rounded, posteromedially desclerotized. Epiproct large, subrectangular, medially split and posteromedially desclerotized, and posteromedially setulose. Cercus elongate, apically rounded with long apical, dorsal, and apicoventral setae. S7 broad, posteromedially expanded with 6–8 large posterior setae; S8 entirely membranous. Hypoproct entirely setulose. Three spermathecae, bulb elongate, cylindrical, finely striate with a deep basal and a shallow apical invagination, both with a small, finger-like, central process.
Distribution
Neotropical: Venezuela.
Remarks
Sclerocoelus dryadalis sp. nov. is similar to the closely related but strongly brachypterous S. flavus sp. nov. and S. meridensis sp. nov., sharing long, scoop-like surstyli, short but wide male S5s, and apically expanded distiphallus. Sclerocoelus dryadalis can be easily separated from these other two species by the fully developed wings and much broader gena. This species, like other basal lineages of the genus, is a high Andean species and is known only from Venezuelan elfin forests at about 4000 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 52-53, DOI: 10.5852/ejt.2025.979.2803, http://zenodo.org/record/14980852