Sclerocoelus masneri 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 masneri

description: Sclerocoelus masneri sp. nov.
urn:lsid:zoobank.org:act: 634CD9CC-C617-4DFF-B008-85712887268A
Figs 7I, 87–89
Etymology
This name is in honour of Dr Lubomir Masner, whose collecting efforts yielded many of the specimens examined during the course of this revision, including most of the specimens of this species.
Material examined
Holotype
VENEZUELA • ♂; Aragua, Rancho Grande Biological Station; 10°21′ N, 67°41′ W; 1200 m a.s.l.; 11 May 1998; Ashe, Brooks and Hanley leg.; flight-intercept trap; DEBU debu00364945.
Paratypes
VENEZUELA – Aragua • 5 ♀♀; same data as for holotype; DEBU • 4 ♂♂, 8 ♀♀; Henri Pittier National Park Highway, Maracay-Choroni, km 19; 1330 m a.s.l.; 15 Apr. 1994; L. Masner leg.; creek; DEBU • 1 ♀; Henri Pittier National Park Highway, Maracay-Choroni, km 32; 100 m a.s.l.; 15 Apr. 1994; L. Masner leg.; forest; DEBU • 4 ♂♂; Henri Pittier National Park, Rancho Grande Biological Station; 14 May 1998; Ashe, Brooks and Hanley leg.; SEMC • 3 ♂♂; Henri Pittier National Park, Rancho Grande; 1100 m a.s.l.; 18 Aug.–3 Oct. 1992; L. Masner leg.; cloud forest, maxinet; DEBU • 23 ♂♂, 17 ♀♀; Henri Pittier National Park, Rancho Grande; 1500 m a.s.l.; 3 Sep. 1992; L. Masner leg.; DEBU • 1 ♀; Henri Pittier National Park, Rancho Grande, La Toma trail; 1100 m a.s.l.; 17 Apr. 1994; L. Masner leg.; DEBU • 15 ♂♂, 3 ♀♀; Henri Pittier National Park, Rancho Grande, La Toma trail; 9 Apr. 1994; L. Masner leg.; DEBU • 2 ♂♂; same data as for preceding; 9–10 Apr. 1994; DEBU • 4 ♂♂; Henri Pittier National Park, Rancho Grande, Portachuelo Pass; 9 Apr. 1994; L. Masner leg.; DEBU • 1 ♀; Henri Pittier National Park, trail along Rancho Grande; 1225 m a.s.l.; 22–25 Jan. 1996; J. and A. Skevington leg.; Malaise in forest opening; DEBU • 1 ♂, 1 ♀; Maracay, Rancho Grande Biological Station; 1200 m a.s.l.; 25–28 Feb. 1995; S.A. Marshall leg.; wet area, pan traps; DEBU • 1 ♂; Maracay, Rancho Grande Biological Station; 8 Mar. 1995; S.A. Marshall leg.; sweep near station; DEBU • 2 ♀♀; Maracay, Rancho Grande; 1–10 Aug. 1987; Bordon and Peck leg.; cloud forest, flight-intercept trap; DEBU • 3 ♂♂; Rancho Grande Biological Station, Portachuelo Pass; 1400 m a.s.l.; 27 Feb. 1995; S.A. Marshall leg.; DEBU • 11 ♂♂, 2 ♀♀; Rancho Grande; 26 Feb. 1989; D.A. Grimaldi leg.; AMNH • 1 ♂; Rancho Grande, La Cumbre cloud forest; 1500 m a.s.l.; 1–10 Aug. 1987; Bordon and Peck leg.; flight-intercept trap; DEBU • 2 ♂♂, 1 ♀; Tiara, 1250 m a.s.l.; 12 Apr. 1994; L. Masner leg.; DEBU.
Description
BODY (Fig. 87A). Length 2.8–3.2 mm. Head dark brown, lower quarter of frons, face, gena, and antenna yellow-orange. Frontal width 2.4–2.5 × frontal height. Two pairs of strong interfrontal bristles surmounting a fine third pair (one female paratype has a third large interfrontal bristle on one side); anterior orbital 0.6–0.7× length of posterior. Palpus white. Eye very large, greatest height about 4.5× shortest genal height. Thorax brown, scutum with slightly paler lateral edges; postpronotum and anterior edge of anepisternum yellow. Two pairs of dorsocentral bristles (anterior pair only slightly larger than surrounding acrostichal setulae) separated by 7–8 rows of acrostichal setulae. Membrane around prosternum bare. Legs yellow, hind tibia darker. Fore femur with three large ventral preapical setae. Ventral surface of male mid tibia with two rows of stout setae along apical half. Wing (Fig. 7I) slightly infuscate. CS2 0.7–0.8 × CS3. Halter pale brown.
MALE ABDOMEN (Figs 87B–C, 88). Dark brown, posterior edges of tergites sometimes slightly desclerotized. T2–5 and S2–4 uniformly long-setose with large posterolateral setae. S5 triangular, 2.2× length of S4, laterally long-setose with a dark, elongate patch of dense setulae flanked by patches of long setae and broad pale areas, patch of setulae bulging ventrally. Anterior flange of S6+7 very large, rectangular, 2.5 × as long as wide. Sclerite A rounded, densely setulose with a pair of lateral setae, narrowly joined to S6+7; sclerites B and C absent; sclerites D and E dark, elongate, slightly sinuate, separate but closely associated, appearing as a single V-shaped sclerite; sclerite F large, dark, triangular, inner surface concave; sclerite G small, rounded, laterally with a patch of setulae; ring sclerite dark, well developed. Epandrium moderate, 0.7 × length of S8, height 1.6× maximum length and 0.8× maximum width; perianal pads weakly developed. Pseudocercus elongate, separate from epandrium, and bearing three setae; halves of subepandrial sclerite curved (only inner half of an arch), connected medially by a broad, sheet-like sclerotization. Subcercus large, laterally flattened, trapezoidal with pointed anteroventral and posteroventral corners, posteroventral edge setulose and curved inwards. Hypandrium with sinuate, apically expanded anteromedial apodeme. Surstylus pure white, triangular with a rectangular anterobasal lobe and a curved, subtriangular lobe about midway along anteroventral edge, ventral surface of apical third densely setose. Postgonite moderate, slightly bent forwards, apex greatly expanded with a small, preapical, anterior lobe. Phallapodeme large, gently curved with a large, dorsal ‘fin’; basiphallus with a stout, knuckle-like basal part and an elongate antero-distal part which articulates with dorsal surface of distiphallus; distiphallus C-shaped in lateral view, largely membranous with a large, flattened dorsal sclerite and a pair of smaller posteroventral sclerites.
FEMALE ABDOMEN (Fig. 89). T7 broad, simple, posteromedially emarginate; T8 divided into a large, pale, dorsal sclerite and two large, dark, lateral sclerites, posterolateral corners slightly expanded and rounded. Epiproct large, broad, subtriangular, anteromedially and posteromedially desclerotized, and almost entirely setulose. Cercus elongate, apically pointed with long apical, dorsal, and apicoventral setae. S7 broad, long, posterior half desclerotized with 4–5 large posterior setae, each seta in desclerotization with a sclerotized base; S8 divided into two dark, rounded, lateral sclerites. Hypoproct with thickened anteromedial setulae. Three spermathecae, bulb stout, bean-shaped, finely striate with large basal and subapical invaginations, subbasal invagination with a large, finger-like, central process.
Distribution
Neotropical: Venezuela.
Remarks
Sclerocoelus masneri sp. nov. is similar to other members of the S. dasysternum group but is easily recognized by the distinctive white surstylus, very long posteromedial patch of setulae on the male S5, apically expanded postgonite, and widely desclerotized posterior half of the female S7. Sclerocoelus masneri is known only from relatively low elevation cloud forests in Venezuela, where it seems to be relatively common; multiple collectors, including the senior author, have repeatedly collected this species in the cloud forest of Rancho Grande in Henri Pittier National Park. It is a member of the mostly Central American S. dasysternum group.
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 77-79, DOI: 10.5852/ejt.2025.979.2803, http://zenodo.org/record/14980852