Sclerocoelus irregularis 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 irregularis

description: Sclerocoelus irregularis sp. nov.
urn:lsid:zoobank.org:act: FABBDFAE-64C9-43A9-9923-4630D4602054
Figs 7B, 66–68
Etymology
This name reflects the overall similarity of this species to the very closely related Sclerocoelus regularis (from the Latin prefix ‘ ir -’, meaning ‘not’).
Material examined
Holotype
ECUADOR • ♂; Pichincha, Maquipucuna Biological Reserve; 0°07′23″ N, 78°37′57″ W; 1200 m a.s.l.; 27–28 Apr. 2002; M. Buck leg.; sweep; QCAZ.
Paratypes
ARGENTINA – Misiones • 1 ♀; 5 km E of Puerto Iguazú; 1–6 Feb. 1992; S.A. Marshall leg.; sweep Malaise; DEBU. – Salta • 1 ♂, 1 ♀; 30 km E of Salta, El Alisal, Campo Quijano; 18 Feb. 1992; S.A. Marshall leg.; forest vestige; DEBU • 3 ♂♂; Campo Quijano, road to San Antonia De Los Cobres, above forest level, site 2 and 3; 18 Feb. 1992; S.A. Marshall leg.; DEBU • 1 ♂; El Rey National Park, Aguas Negras Trail; 900 m a.s.l.; 11–15 Dec. 1987; S. and J. Peck leg.; forest, Malaise trap; DEBU • 5 ♂♂, 1 ♀; El Rey National Park, Rio La Sala; 900 m a.s.l.; 5–10 Dec. 1987; S. and J. Peck leg.; open stream side in forest, Malaise trap, flight-intercept trap; DEBU • 2 ♂♂; La Caldera Camino, la Cornisa; 27 Feb. 1992; S.A. Marshall leg.; roadside forest sweeps; DEBU • 5 ♂♂; Rosario De Lerma; 29 Feb. 1992; S.A. Marshall leg.; foul mud, wet vegetation; DEBU • 6 ♂♂, 9 ♀♀; Rosario De Lerma, INESALT yard; 16–28 Feb. 1992; S.A. Marshall leg.; Malaise trap; DEBU • 5 ♀♀; same data as for preceding; 17–28 Feb. 1992; pan traps; DEBU • 1 ♀; same data as for preceding; 17 Feb.–1 Mar. 1992; general collecting; DEBU • 1 ♂; Rosario De Lerma; 29 Feb. 1992; S.A. Marshall leg.; meadow, sweep; DEBU • 2 ♂♂, 3 ♀♀; same collecting data as preceding; swept in hedgerow ditch; DEBU • 2 ♂♂, 4 ♀♀; same collecting data as preceding; 19 Feb. 1992; swept in wet hedgerow ditch; DEBU • 22 ♂♂, 22 ♀♀; same collecting data as preceding; 24 Feb. 1992; swept over bulldozed road; DEBU • 1 ♂; same collecting data as preceding; 14 Feb. 1992; swept over foul ditch; DEBU • 1 ♂; Sumalao; 19 Feb. 1992; S.A. Marshall leg.; wet muddy area along field, sweep; DEBU.
BOLIVIA – La Paz • 2 ♀♀; Chulumani, Apa-Apa Reserve; 16°21′15″ S, 67°30′21″ W; 2000 m a.s.l.; 1 Apr. 2001; S.A. Marshall leg.; sweep; CBFC. – Santa Cruz • 2 ♂♂, 4 ♀♀; Campo Guairuy, 24 km S of Camiri; 870 m a.s.l.; 18 Aug.–2 Sep. 2000; Irwin and Hauser leg.; Malaise trap; DEBU • 2 ♂♂; Quebrada Isiri, 20 km S of Camiri; 865 m a.s.l.; 18 Aug.–2 Sep. 2000; Irwin and Hauser leg.; Malaise trap; CBFC.
BRAZIL – Minas Gerais • 1 ♂; Prado; 21 Feb. 1990; S.A. Marshall leg.; sweep along river; MZSP. – Paraná • 1 ♂; Curitiba campus; 10 Feb. 1990; S.A. Marshall leg.; sweep in forest with Araucaria; DEBU • 2 ♂♂, 1 ♀; Curitiba; 5 Feb. 1990; S.A. Marshall leg.; underneath fallen epiphytes near National History Museum; MZSP • 5 ♀♀; Curitiba, University campus; 7 Feb. 1990; S.A. Marshall leg.; dirty water, sweep; MZSP • 2 ♂♂, 2 ♀♀; same data as for preceding; 2–5 Feb. 1990; wet areas, flight-intercept trap/pans; DEBU • 3 ♂♂, 3 ♀♀; East of Curitiba; 8 Feb. 1990; S.A. Marshall leg.; sweep near creek debris; MZSP • 1 ♀; Morretes, 5 km S of Sapidontuva; 9 Feb. 1990; S.A. Marshall leg.; MZSP • 1 ♀; Palmas, Linha Alegria, Fazenda Cerro Chato; 26°30′09″ S, 51°40′13″ W; 1224 m a.s.l.; 3–4 Mar. 2015; Savaris and Norrbom leg.; on hill in campo, Malaise trap; DEBU. – Rio de Janeiro • 2 ♀♀; Jacaré Paguá; 22 Jan. 1990; S.A. Marshall leg.; wet litter by stream; MZSP • 1 ♂; Muri, near Hotel Garlipp; 2 Mar. 1990; S.A. Marshall leg.; sweep over trail; MZSP • 1 ♂, 1 ♀; Nova Friburgo, Sitio Edelweiss; 26 Jan. 1990; S.A. Marshall leg.; Malaise trap; MZSP • 1 ♀; Nova Friburgo; 27 Jan. 1990; S.A. Marshall leg.; along creek; MZSP • 1 ♀; Represandos Ciganos; 22–24 Jan. 1990; S.A. Marshall leg.; Malaise head; MZSP • 2 ♂♂; Tijuca; 28 Feb. 1990; S.A. Marshall leg.; forest; DEBU – Santa Catarina • 1 ♂, 1 ♀; Aparados da Serra National Park, Rio do Boi; 29°12′08″ N, 50°03′01″ W; 209 m a.s.l.; 6–8 Mar. 2015; Norrbom and Savaris leg.; river crossing, Malaise trap; DEBU.
ECUADOR – Chimborazo • 1 ♂; Bugna; 1400 m a.s.l.; Levi-Castillo leg.; USNM • 1 ♂; Linje Chimborazo; Jul. 1955; Levi-Castillo leg.; USNM. – Cotopaxi • 1 ♂; 66 km E of Quevedo; 15 Jan. 1978; W.N. Mathis leg.; USNM. – El Oro • 1 ♀; Río Palenque; 27 Feb. 1979; S.A. Marshall leg.; dung; DEBU. – Guayas • 1 ♂, 1 ♀; 16 km N of Manglar Alto; 30 Jan. 1955; E.I. Schlinger and E.S. Ross leg.; CAS. – Los Ríos • 4 ♂♂, 4 ♀♀; Pichilingue; 40 m a.s.l.; 2 Feb. 1955; E.I. Schlinger and E.S. Ross leg.; CAS. – Manabí • 1 ♂, 1 ♀; Montecristi; Feb. 1983; M. Sharkey leg.; CNCI. – Pichincha • 7 ♂♂, 4 ♀♀; same data as for holotype; DEBU • 7 ♂♂, 5 ♀♀; same data as for holotype; QCAZ • 2 ♂♂; 7 km SE of Nanegalito, trout farm ‘San Jose’; 1500 m a.s.l.; 27–30 Oct. 1999; S.A. Marshall leg.; riverine forest, treefall sweeps; QCAZ • 1 ♂; 9.7 km E of Santo Domingo de los Colorados; 24 Feb. 1955; E.I. Schlinger and E.S. Ross leg.; CAS • 2 ♂♂, 2 ♀♀; 27 km S of Santo Domingo, Rio Palenque Station; 250 m a.s.l.; 17–25 Feb. 1979; S.A. Marshall leg.; QCAZ • 1 ♂; same data as for holotype; 1400–1700 m a.s.l.; 27 Apr. 2002; S.A. Marshall leg.; main trail; DEBU • 4 ♂♂, 2 ♀♀; Maquipucuna Biological Reserve, 1300 m a.s.l.; 27 Oct. 1999; S.A. Marshall leg.; main trail; QCAZ • 9 ♂♂, 2 ♀♀; same data as for preceding; 1200 m a.s.l.; 29 Oct. 1999; river trail, sweeping; DEBU • 10 ♂♂, 2 ♀♀; same data as for preceding; QCAZ • 2 ♂♂; same collecting data as preceding; 27 Oct. 1999; QCAZ • 1 ♂; Rio Palenque Station, 47 km S of Santo Domingo; 160–190 m a.s.l.; 1–4 May 1987; L.D. Coote leg.; primary rainforest, screen sweep; ROME • 1 ♂, 2 ♀♀; Rio Palenque Station, 47 km S of Santo Domingo; 180 m a.s.l.; 29.Apr.–5 May 1987; L.D. Coote and B.V. Brown leg.; 1° lowland rainforest, Malaise head; ROME • 1 ♀; Tinalandia; 800 m a.s.l.; 2–7 Feb. 1983; M. Sharkey and L. Masner leg.; Malaise trap; CNCI.
PARAGUAY – Caazapá • 1 ♀; Hermosa, San Rafael Reserve, Lopez family property; 26°19′15″ S, 55°44′55″ W; 90 m a.s.l.; 3–6 Dec. 2000; Z.H. Falin leg.; flight-intercept trap; DEBU.
Other material examined
COSTA RICA – Guanacaste • 1 ♂; Area de Conservacion Guanacaste, Pailas Dos; 10°45′46.8″ N, 85°00′02.4″ W; 831 m a.s.l.; 20 Sep. 2018; D. Janzen and W. Hallwachs leg.; moist lowland forest, Malaise trap; BIOUG60939-D12/PLFDS108-20 sequenced for CO1-5; BIOUG.
Description
BODY (Fig. 66A). Length 2.0– 3.1 mm. Head brown, lower half of frons orange; face, gena, and antennae orange-brown. Frontal width 2.3–2.4× frontal height. Three pairs of strong interfrontal bristles surmounting a very fine fourth pair; anterior orbital 0.6–0.7 × 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, 0.3× length of posterior pair) separated by 8–9 rows of acrostichal setulae. Membrane around prosternum bare. Legs yellow, mid and hind femora brownish. 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. 7B) hyaline. CS2 0.8–0.9× CS3. Halter pale brown.
MALE ABDOMEN (Figs 66B–D, 67). Dark brown, tergites reddish medially, posterior edges of tergites slightly desclerotized. T2–5 and S2–4 uniformly long-setose with large posterolateral setae. S5 rectangular, 1.1 × as long as S4, right side longer than left side, posterolaterally long setose with a large desclerotized medial area (extending about halfway to anterior edge), a dark, ovoid, medial patch of dense but fine setulae, and a large, dark, anvil-shaped posteromedial sclerite. Anterior flange of S6+7 1.0× as long as wide. Sclerite A small, lightly sclerotized; sclerite B well developed and long, normally arched into genital pouch; sclerite C absent; sclerite D well sclerotized and L-shaped; sclerite E small, fitting into a depression in distal half of large sclerite F; sclerite G smaller than ring sclerite; ring sclerite well sclerotized. Epandrium large, 0.9× length of S8, height 1.3× maximum length and 0.8× maximum width, uniformly long-setose; perianal pads weakly developed but densely setulose. Pseudocercus very small, bearing only a single seta; halves of subepandrial sclerite short and narrow, C-shaped with a thin mesial lobe and very weakly fused medially. Subcercus large and shield-like with small lobes articulating with surstylus and epandrium, apex weakly pointed. Hypandrium with long anteromedial apodeme with pair of thin posterobasal lobes. Surstylus very large and broad, twice as long as deep, inner surface concave, with dense lateral setae and a setose inner basal ridge (ridge entire). Postgonite relatively long, almost straight, uniformly broad, apex swollen with prominent ridges. Phallapodeme large, gradually broadened towards apex; basiphallus expanded posterodorsally with a pointed central lobe and a pair of round, downturned lateral lobes, basal part extending ventrally as an apically flared tube-like section which articulates with distiphallus; distiphallus largely reduced with a broad dorsal sclerite and a narrow, U-shaped ventral sclerite.
FEMALE ABDOMEN (Fig. 68). T7 broad, posteromedially shortened; T8 divided into a small, pale dorsal sclerite and two dark lateral sclerites with angulate posteroventral corner. Epiproct small, pale, and posteromedially setulose. Cercus narrow and elongate with a large apical seta and a moderate preapical seta. S7 broad, rounded posteriorly with four large posterior setae; S8 reduced to two dark, ovoid lateral sclerites. Three spermathecae, single one larger than paired ones, bulb bean-shaped and smooth with a slight basal invagination.
Distribution
Neotropical: Argentina, Bolivia, Brazil, Costa Rica, Ecuador, Paraguay.
Remarks
Sclerocoelus irregularis sp. nov. resembles S. dominicensis sp. nov., S. pararegularis sp. nov., and S. regularis, from which it differs in having males with a straight postgonite and a much smaller desclerotized medial area on S5; females of these species appear to be indistinguishable. Sclerocoelus irregularis is widespread in South America and is also known from a single specimen collected in Costa Rica; the three similar species occur in the Caribbean, Mexico, Central America and northern South America.
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 64-66, DOI: 10.5852/ejt.2025.979.2803, http://zenodo.org/record/14980852