Syringogaster dactylopleura Marshall & Buck

Marshall, S. A., Buck, M., Skevington, J. H. & Grimaldi, D., 2009, A revision of the family Syringogastridae (Diptera: Diopsoidea), Zootaxa 1996 (1), pp. 1-80: 40-43

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Syringogaster dactylopleura Marshall & Buck

new species

Syringogaster dactylopleura Marshall & Buck   , new species

Figs. 33–36; Plates 3D, 4C, 5C; Map 6

DESCRIPTION: Head yellow except dark ocellar tubercle. Ocellar triangle slightly raised above orbits, shining, transparent, almost parallel-sided and slightly tapered to a rounded front; bordered on each side by a row of 3 small inclinate bristles, anterior apex separated from frontal margin by 1–2 scape lengths; remainder of frons tomentose and dull. Vertex straight or very weakly convex at middle. Ocellar bristles absent, ocellar triangle glabrous. Parafacial with sparse long brown hairs; shining vibrissal angle without bristles. Shining subgena concave, shorter than setose gena. Clypeus narrow, no wider than face. Supracervical collar prominent and convex, equal in length to middle of pronotum.

Thorax: Pronotum black along anterior margin, with a prominent transverse carina laterally and parallel black lines medially. Mesonotum shining orange anteriorly, becoming tomentose at level of humeral pit and usually gradually phasing to dark brown, usually entirely dark posterior to suture (see notes on variation below); humeral pit black with a very high black carina extending laterally more than the width of the pit. Notopleural carina prominent and triangular, postpronotum between notopleural and humeral carinae convex and shining. Supra-alar carina well developed, bilamellate posteriorly, posterior parts of lamellae obsolete. Entire mesopleuron and postmetacoxal bridge shining orange-brown, bare except for a few scattered hairs on former. First prespiracular process a short, black, triangular tooth extending posteriorly towards the strikingly long, finger-like second prespiracular process. Postnotum brown and tomentose. Fore coxa, trochanter, base of femur and tarsomeres 2–5 pale yellow to white, tibia dark brown, balance of leg yellow-brown. Anteroventral margin of distal part of fore femur with row of 5–8 short stout, dark bristles, increasing in size proximally. Inner surface of fore tibia with a patch of dense yellow setae covering distal half, bristles otherwise brown. Mid femur white basally, pale brown distally. Mid tarsomeres 1–4 with antero- and posteroventral sawlines. Hind femur with a white base followed by a narrow, oblique brown band, rest orange-brown, anteroventral row of 7–8 spines extending over distal 3/5 of femur, posteroventral row shorter. Hind tibia with apex weakly trilobate, lobes subequal. Anterior sawlines of hind tarsomeres as described for mid leg.

Wing clear with small dark patches over all crossveins, and an indistinct oval discal band extending from below apex of R 2+3 to dm-cu. Fork of CuA distal of bm-cu by about half length of bm-cu; A 1 +CuA 2 distinct but extending less than half way from cup to wing margin; CuA 1 extending over half way from dm to wing margin. R 2+3 turned up to costa near apex. Cell r 4+5 gradually widening beyond r-m, not abruptly tapered to rm; r-m about half as long as dm-cu.

Abdomen: Syntergite 1–3 narrow at base, tergites 1 and 2 parallel-sided and smooth except for weak transverse striations near base, tergite 3 gradually widening to an apex twice as wide as base, length 3X width at apex. Syntergite shining, without pits or microsetulae but with irregular longitudinal grooves at least in basal 2/3, sparsely setose. Background color pale shining brown, syntergite 1–3 dark basally and yellow distally.

Female terminalia: Four spermathecae in two pairs, each pair made up of tightly appressed acorn-shaped spermathecae made up of a tire-shaped base and a conical cap that is over half as wide and 1.25X as long as base.

Male terminalia: Postabdomen entirely pale. Tergites 5 and 6 unmodified, ventrolateral margins straight; spiracles 5 in membrane, spiracles 6 in tergite at margin. Sternites 4 and 5 small and pale, synsternite 7+8 very short, ventral part of ring weak and almost linear, right spiracle 7 considerably more ventrally positioned than left spiracle. Epandrium wider than long. Cercus small, much shorter than the large mitt-shaped surstylus; the latter with a series of very long hairs at ventral margin. Subepandrial sclerite well-developed, divided into two transverse L-shaped sclerites whose short arms bend forward medially, posteromedially articulating with dorsal extension of basiphallus and anterolaterally articulating with hypandrium. Hypandrium with broadly interrupted hypandrial bridge, otherwise without interruptions or internal articulations; ventral hypandrial lobe very broad, curved medially and anteriorly, slightly wider at apex than near middle. Postgonite large, simple and dark. Pregonite large, shaped like a twisted triangular plate. Basiphallus elongate, distal part expanded into two broad lateral lobes. Distiphallus short and broad, curved sinistrally, with prominent lobes on each side; lobe on right side flat and broad, lobe on left side long and narrow; distal part broad and extensively, densely spinulose.

TYPE MATERIAL: Holotype ♂ ( CBFC)   : BOLIVIA. La Paz, Arroyo Tuhiri , 5 km W Mapiri, 508 m, 15°17.8’S, 68°15.6’W, 10.iv.2001, S.A. Marshall, debu00190188 GoogleMaps   . Paratypes: Same locality as holotype but 16–19.iii.2001 and 9.iv.2004, S.D. Gaimari, (2♂, 2♀, USNM, CBFC, CSCA) GoogleMaps   . ECUADOR. Napo, Jatun Sacha Biological Station , 6 km E Misahuallí, 450 m, 1°4’S, 77°37’W, 30.iv–8.v.2002, on foliage, M. Buck (1♂, DEBU, debu00186457) GoogleMaps   ; Tena , ii.1983, M. Sharkey (1♂, DEBU)   ; Napo, Puerto Misahuallí , 350 m, ii.1983, M.J. Sharkey (1♀, CNCI)   ; Puerto   Orellana, Río Tiputini , 10°38.2’S, 76°8.9’W, 12–26.viii.1999, W.N. Mathis, A. Baptista & M. Kotrba (1♂, 1♀, USNM) GoogleMaps   ; Reserva Etnica Waorani, 1 km S Onkone Gare Camp, Transect Ent. ,, 0°39’25.7”S, 76°27’10.8”W, 216.3 m, T. L. Erwin et al., Trans. 5, Sta. 3, fogging in terra firme forest, Lot #732 (1♂, USNM) GoogleMaps   ; as above but Trans. 10, Sta. 1, 6.x.1994, Lot #880 (1♀, USNM)   ; as above but Trans. 10, Sta. 2, 23.i.1994, 0°39’26”S, 76°27’11”W, 220 m, Lot #631 (1♂, USNM) GoogleMaps   . PERU. Madre de Dios, Manú, Erika (near Salvación ), 550 m, 5–6.ix.1998, A. Freidberg (2♂, 1♀, USNM)   ; Huánuco, Tingo María (6 km NW)   , Tingo María Natl. Park , 9.ii.1984, W.N. Mathis (1♀, USNM)   ; Madre de Dios, Los Amigos Biological Station , 2–, S.M. Paiero & J. Klymko (1♂, 1♀ for sequencing, DEBU)   ; 220 m, Dpto. Huánuco, Río Llullapichis, right tributary of Río Pachitea, Station “Panguana” (of H.-W. Koepcke ), 9°36’53”S, 74°55’57”W, primary forest, 50 yellow pan traps in a 300 m long row, for 15 days in ix.1981, daily checks, M. v. Tschirnhaus, “X274” (3♂, 1♀, DEBU) GoogleMaps   .

ETYMOLOGY: The specific epithet refers to the remarkable narrow and digitate lobe projecting over the posterior spiracle.

COMMENTS: The paratypes from Ecuador   are much paler than the specimens from Bolivia and Peru, and the range from the almost entirely reddish brown Ecuadorian specimens through to the mostly black Bolivian specimens is much greater than the color variation noted in other species. Genitalic and other characters, however, do not vary along with color and we are therefore treating this as a single species varying from dark in relatively southern localities ( Bolivia) through to pale in relatively northern localities ( Ecuador).

Syringogaster dactylopleura   is characterized by several unique characters such as the prominent posterior prespiracular process, fringe of very long bristles of surstylus (longest as long as surstylus), widely interrupted hypandrial bridge, L-shaped halves of subepandrial sclerite that articulate with basiphallus, and spinulose apex of distiphallus lacking striate areas. This species is the sister species of the figurata   -subgroup.


Smithsonian Institution, National Museum of Natural History


California State Collection of Arthropods


Ontario Insect Collection, University of Guelph


Canadian National Collection Insects


Tavera, Department of Geology and Geophysics