Sclerocoelus dasysternum 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 dasysternum

description: Sclerocoelus dasysternum sp. nov.
urn:lsid:zoobank.org:act: 8F711293-B3B8-4325-9CDE-8D85F2B3DFB9
Figs 6C, 42–44
Etymology
The species name (from the Greek ‘ dasus ’, meaning ‘hairy, shaggy’) refers to the additional tuft of setulae anterior to the posteromedial patch of setulae found on the male S5.
Material examined
Holotype
COSTA RICA • ♂; Guanacaste, Cacao Field Station; 1000–1100 m a.s.l.; 12–15 Feb. 1996; S.A. Marshall leg.; carrion traps; MNCR.
Paratypes
COSTA RICA – Alajuela • 1 ♂; Volcán Tenorio, N slope near Bijagua Biological Station; 700 m a.s.l.; 18 Jun. 2000; S.A. Marshall leg.; MNCR. – Cartago • 1 ♂; La Suiza; P. Schild leg.; USNM. – Guanacaste • 1 ♂; Maritza; 15–17 Feb. 1996; S.A. Marshall leg.; dung pan; DEBU • 1 ♂, 1 ♀; SW of Faldas, Volcán Cacao; 1250–1350 m a.s.l.; 12 Feb. 1996; S.A. Marshall leg.; MNCR. – Puntarenas • 2 ♂♂, 2 ♀♀; 6 km ENE of Vara Blanca; 10°11′ N, 84°07′ W; 2000 m a.s.l.; 21 Feb. 2002; transect; DEBU • 2 ♂♂, 1 ♀; same data as for preceding; MNCR • 2 ♂♂; Monteverde; 1520 m a.s.l.; 18–25 Jun. 1983; D.H. Lindeman leg.; flight-intercept trap; DEBU • 2 ♂♂; Monteverde; 26 May 1998; S.A. Marshall leg.; sweep near Biological Station; MNCR. – San José • 1 ♀; Moravia, Zurquí de Moravia; 10°02′58″ N, 84°00′57″ W; 1600 m a.s.l.; 12–18 Sep. 2012; Proyecto ZADBI leg.; Malaise trap #2; MNCR • 1 ♀; same data as for preceding; 24 Sep. 2012; creek river 2, pan light trap; MNCR.
GUATEMALA – Suchitepéquez • 1 ♂; 4 km S of Volcán Atitlán; 14°32′57″ N, 91°11′26″ W; 1625 m a.s.l.; 15 Jun. 2009; cloud forest, sifted leaf litter; UVGC.
HONDURAS – Olancho • 1 ♂; La Muralla National Park; 15°05′49″ N, 86°44′17″ W; 1450 m a.s.l.; 4–7 Jul. 2002; Smith and Ocampo leg.; flight-intercept trap; CNCI.
PANAMA – Chiriquí • 1 ♂; Hartmann’s Finca; 1700 m a.s.l.; 28 Jun.–3 Jul. 1981; B. Gill leg.; DEBU.
TOBAGO – Eastern Tobago • 1 ♂; Charlotteville, Man-o-war Bay cottages; 26–31 Jun. 1993; S. and J. Peck leg.; littoral rainforest, UV light; DEBU.
Other material examined
COSTA RICA – Guanacaste • 1 ♂; Area de Conservacion Guanacaste, Pailas Dos; 10°45′39.6″ N, 85°20′06.0″ W; 791 m a.s.l.; 31 May 2018; D. Janzen and W. Hallwachs leg.; moist lowland forest, Malaise trap; BIOUG58387 -C07/ PLIDC254-20 sequenced for CO1-5’; BIOUG.
Description
BODY (Fig. 42A). Length 2.4–2.8 mm. Head brown, lower half of frons, face, gena, and antennae yellow. Frontal width 2.2–2.3 × frontal height. Two pairs of strong interfrontal bristles surmounting a fine third pair; anterior orbital 0.4–0.5 × length of posterior. Palpus yellow. Eye large, greatest height about 3.5× shortest genal height. Thorax brown, scutum with paler lateral edges. Two pairs of dorsocentral bristles (anterior pair distinct, 0.4 × length of posterior pair) separated by 7–8 rows of acrostichal setulae. Membrane around prosternum bare. Legs yellow, hind leg slightly darker. Fore femur with three large ventral preapical setae. Ventral surface of male mid tibia with two rows of stout setae in apical quarter. Wing (Fig. 6C) slightly infuscate. CS2 0.5–0.6 × CS3. Halter pale brown.
MALE ABDOMEN (Figs 42B–C, 43). 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, sparsely setose, slightly emarginate anteromedially with a dark, distally tapered, slightly bulging patch of dense setulae flanked by pale setose areas. Anterior flange of S6+7 large, 0.8× as long as wide. Sclerite A small, pale; sclerite B reduced, arched and fused to sclerite A; sclerite C reduced; sclerite D club-shaped, associated with inner posterior margin of S5; sclerite E well sclerotized, elongate, curved and slightly tapered; sclerite F large, subquadrate and laterally concave, left side with an elongate apicoventral process; sclerite G dark with a prominent, ridge-like process connecting to sclerite F; ring sclerite small, dark. Epandrium small, 0.5 × length of S8, height 1.3× maximum length and 0.8× maximum width, uniformly setose; anal fissure elongate; perianal pads weakly developed. Pseudocercus large, pale, bearing three setae and fused to posteroventral corners of epandrium; halves of subepandrial sclerite strongly arched, slightly flattened, and completely separate. Subcercus short but deep, subtriangular in posterior view, ventrally with a narrow, dark process, anterior part narrowed and carinate dorsally. Hypandrium with narrow anteromedial apodeme. Surstylus subquadrate, rounded, laterally setulose, ventrally setose, inner surface with anterodorsal lobe and a dark, bifurcate carina on dorsal half near middle. Postgonite short, broadened posteriorly into a broad triangle with a small, apical digitate process. Phallapodeme large, apex spoon-shaped; basiphallus small, slightly elongate with a flattened, triangular epiphallus; distiphallus reduced, largely membranous with a pair of pale Y-shaped lateral sclerites.
FEMALE ABDOMEN (Fig. 44). T7 broad, simple; T8 divided into a small, pale, dorsal sclerite and two dark, lateral sclerites, posterolateral corners elongate and pointed. Epiproct broad, ovoid, medially split and entirely setulose. Cercus elongate, pointed with long apical and dorsal setae. S7 large, broad, posteriorly desclerotized with four large posterior setae; S8 well developed, deeply emarginate anteromedially, almost divided. Hypoproct with thick ventromedial setulae. Three spermathecae, bulb stout, bean-shaped, moderately striate with deep invaginations at apex and insertion point of duct (perpendicular to apex), both invaginations with a finger-like, central process.
Distribution
Neotropical: Costa Rica, Guatemala, Honduras, Panama, Tobago.
Remarks
Sclerocoelus dasysternum sp. nov. is superficially very similar to the closely related S. costaricensis sp. nov., but differs by the yellow gena, smaller eye (~3.5 × genal height), shorter second costal sector (0.5–0.6 × length of third), and two dark posteromedial patches of setulae on the male S5. Sclerocoelus dasysternum, a member of the mostly Central American S. dasysternum group, is one of four endemic Costa Rican Sclerocoelus.
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 49-50, DOI: 10.5852/ejt.2025.979.2803, http://zenodo.org/record/14980852