Syringogaster apiculata Marshall & Buck, 2009

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 : 20-22

Syringogaster apiculata Marshall & Buck , new species

Figs. 4–8; Plate 3E; Map 1

DESCRIPTION: Head orange except darker ocellar tubercle. Vertex strongly convex at middle. Ocellar triangle shining, bordered on each side by a row of minute inclinate bristles, anterior apex separated from frontal margin by width of first flagellomere; remainder of frons tomentose and dull. Ocellar bristles probably strong (broken off in both type specimens). Anteromedial surface of pedicel shining. Parafacial with scattered dark setulae around vibrissal angle. Gena and subgena subequal in height, gena with a row of fine black bristles. Hypostomal bridge slightly longer than in other species of the rufa -group, subequal in length to diameter of foramen.

Thorax orange, variably marked with medium or dark brown; mesoscutum largely medium brown behind transverse suture (scutellum somewhat darkened medially in one of the male types), mediotergite with a brown median band (sometimes indistinct), pleuron with dark brown to black band from mid coxa through prespiracular process to lower calypter (portion below calypter sometimes indistinct); postmetacoxal bridge largely dark brown or concolorous orange-brown. (The single female type from Peru is less distinctly marked, with distinct dark markings limited to the band between mid coxa and prespiracular process and postmetacoxal bridge). Pronotal collar with a strong transverse carina on each side; antepronotum and propleuron shining, notum otherwise dull, tomentose and mostly sparsely setulose. Notopleural carina and humeral carina small but distinct, postpronotum slightly raised, dull, tomentose posteriorly; black humeral carina short, restricted to anterior face of humeral pit. Mesopleuron shining except for tomentose posterodorsal area of anepisternum; lower anepisternum, katepisternum and anepimeron with scattered fine pale bristles. Laterotergite with carinate anterior margin raised well above anepimeron. First prespiracular process small and knob-like, at the end of an elevated ridge; second prespiracular process shining and triangular. Subspiracular carina low, anterior part bare, posterior part tomentose dorsally. Supra-alar carina distinct but low. Fore coxa and trochanter white in males (yellow in female from Peru), otherwise fore leg yellow to orange-brown; all fore leg bristles pale. Fore femur without black spinules ventrally. Mid femur white basally, rest of leg orange-brown. Mid tarsomeres 1–3 and basal half of tarsomere 4 with antero- and posteroventral sawlines. Hind femur 3.5–4.0X as long as wide in lateral view, with a white basal ring followed by a brown ring of similar length; remainder of leg orange-brown. Hind femur with anteroventral row of 8–10 spines extending over distal 2/3 of femur, posteroventral row shorter. Hind tibia with apex trilobate, lobes unequal, apicoventral lobe conspicuously more prominent than other lobes. Hind tarsus with anteroventral sawlines on tarsomeres 1–3 or 4 (if present on latter consisting of 1–2 spinules), posteroventral sawlines of tarsomeres 2–3 just over half as long as tarsomeres, sawline of tarsomere 4, if present, consisting of 1–2 spinules.

Wing clear with large and dark patches over all crossveins, patches over basal crossveins forming complete band from front to hind margin of wing; a large, dark oval discal band from apex of R 2+3 to dm-cu, very faintly reaching hind margin of wing, broadly connected at level of M with brown spot around r-m and adjacent section of cell r 2+3. R 2+3 running to costa at an acute angle, not distinctly turned up near apex. Cell r 4+5 gradually widening beyond r-m, not abruptly tapered to r-m; r-m about half as long as dm-cu. Fork of CuA distal of bm-cu by about 0.7–1.0X length of bm-cu; CuA 1 and A 1 +CuA 2 extending almost to wing margin.

Abdomen: Syntergite 1–3 elongate, tergites 1 and 2 parallel-sided; tergite 1 granulose and wrinkled, sparsely tomentose, tergites 2–3 subshining with sparse setulae and a few easily overlooked microtrichia. Background color reddish, syntergite often with a dark basal ring or dorsobasal spot and median ring or dorsomedial spot (dorsally often elongate); tergites 4–6 (and usually part of 3) dark brown (becoming paler posteriorly). Surface almost smooth; minute pitting visible only under very high magnification. Tergites 2 and 3 fused but delineated by a distinct suture; tergite 4 not fused with tergite 3.

Female terminalia: not studied.

Male terminalia: Tergites 5 and 6 unmodified, ventrolateral margins straight. Spiracles 5 in membrane, spiracles 6 exactly at the edge of the tergite, half in membrane, half in tergite. Sternites 5 and 6 each reduced to a pair of small, pale sclerites each with several long bristles; synsternite 7+8 weak ventrally. Epandrium about twice as wide as long. Cercus almost sessile, long-setose, much smaller than surstylus. Surstylus oval, outer surface with bristles that are shorter than length of surstylus, apical margin with a small point (best seen in medial edge-on view). Hypandrium without internal interruptions or articulations; anterior U-shaped portion forming simple ventral band without anterior apodemes; hypandrial bridge narrow. Ventral hypandrial lobe relatively long, expanded, round and long-setose at apex; posterior part of hypandrial arm short and broad, articulating with pregonite with three lobes of characteristic shape; heavily sclerotized, black medial lobe wide and broadly rounded (almost truncate), paler ventral lobe broad with slightly emarginate apical margin, posterior lobe the narrowest and the palest of the three. Subepandrial sclerite reduced and inconspicuous. Basiphallus narrowly cylindrical at base, greatly expanded and asymmetrical distally with right lateral lobe larger than that of left side, both lobes broadly rounded at apex; dorsoapical lobes both evenly rounded. Distiphallus directed sinistrally, distally with one large, sickle-shaped lobe and one short and thin finger-like lobe; base of former with a small, inconspicuous tuberculate projection (projection large and lamellate in the closely related S. tenuipes ).

TYPE MATERIAL: Holotype ♂ ( USNM): ECUADOR. Dpto. Orellana, nr. Yasuní Natl. Pk., Tiputini Biodiversity Station , 0°37’55”S, 76°8’39”W, 220–250 m, 7.ii.1999, T .L. Erwin et al., Trans. 6, Sta. 4, fogging in terra firme forest, Lot #2053. Paratypes: ECUADOR. Same as holotype except 8.ii.1999, Trans. 4, Sta. 6, Lot #2035 (1♂, USNM); Napo, Tena , ii.1983, M.J. Sharkey (1♂, DEBU) . PERU. Madre de Dios, Los Amigos Biological Station , 2–14.vi.2006, S.M. Paiero & J. Klymko (1♂, MUSM) .

OTHER MATERIAL EXAMINED (unassociated female): PERU. Madre de Dios, Manú, Río Manú, Pakitza , 250 m, 12°7’S, 70°58’W, 9–23.ix.1988, A. Freidberg (1♀, USNM).

ETYMOLOGY: The name apiculata refers to the finely pointed apex of the surstylus.

COMMENTS: The males of S. apiculata and S. tenuipes have far fewer long hairs on the femora and lower parts of the thorax than other species in the rufa -group. Syringogaster apiculata is very similar to the sympatric S. tenuipes in both external and genitalic characters. The two can be separated based on the characters provided in the key. Further diagnostic characters include: surstylus with finely pointed apex (rounded in S. tenuipes ), basiphallus apex with right lateral lobe much larger than left lateral lobe (lobes inconspicuous and subequal in S. tenuipes ), dorsoapical lobes of basiphallus subequal and broadly rounded (right dorsoapical lobe with shallow depression bordered by medial carina in S. tenuipes , as seen in ventral view); pregonite with dark medial process broad (narrow in S. tenuipes ).