Syringogaster subnearctica Feijen, 1989

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 : 64-69

Syringogaster subnearctica Feijen

Figs. 57, 58; Plate 2D; Map 10

Syringogaster subnearctica Feijen, 1989: 119 .

DESCRIPTION: Head orange except dark shining brown area above supracervical collar and dark brown ocellar tubercle, upper frons darker than lower frons and face. Vertex almost straight, very weakly convex at middle. Frons, including ocellar triangle tomentose; latter bordered on each side by a row of four minute inclinate bristles, strongly tapered and triangular, anterior apex separated from frontal margin by scape length; remainder of frons tomentose but duller than ocellar triangle. Ocellar bristles absent or minute, barely distinguishable from tomentum. Entire pedicel tomentose. Parafacial with thin black bristles on ventral half. Gena and subgena subequal in height, gena with a row of fine brown bristles in addition to bristles on the distinct, shining vibrissal angle. Supracervical collar strongly developed, 3–4X as long as pronotum at middle.

Thorax, except legs, entirely black, shining except for the following tomentose areas: mesonotum (except small spot anterior to humeral carina), upper half of proepisternum, anepisternum (except anteromedial area behind and below spiracle), small dorsomedial area of katepisternum, anepimeron and postnotum. Pronotal collar very short dorsally, strongly convex laterally. Antepronotum setulose except for a narrow ventral strip. Anterior margin of humeral pit with a prominent carina extending well lateral of pit. First prespiracular process very small, narrowly triangular, extending posteriorly towards much larger, broadly triangular second prespiracular process. Subspiracular lamella deeply bilobed, anterior lobe low and shining, posterior lobe much larger and entirely tomentose. Fore coxa and trochanter white, otherwise fore leg yellow to pale brown. Anteroventral margin of distal part of fore femur with row of 3–8 short stout bristles. Mid femur white basally, rest of leg pale brown. Mid tarsomeres 1–3 and basal half of tarsomere 4 with antero- and posterodorsal sawlines. Hind femur with a white basal ring followed by a brown ring of similar length; remainder of leg orange-brown. Hind femur evenly convex dorsobasally, concave dorsally on distal third; anteroventral row of 12–14 spine-like bristles extending over distal 7/10 of femur, posterior row shorter. Hind tibia with apex weakly trilobate, lobes subequal. Hind tarsomeres 1–3 with sawlines, an extremely shortened posteroventral sawline sometimes present on tarsomere 4.

Wing dark with clear patches forming transverse bands before and after crossvein dm-cu and before crossvein bm-cu. Fork of CuA distal to bm-cu, separated from bm-cu by approximately the length of bm-cu (bm-cu weak); A 1 +CuA 2 and CuA 1 each extending slightly less than half way to wing margin. R 2+3 running almost parallel to costa distally, not distinctly turned up to costa near apex. Cell r 4+5 greatly tapered from apex to level of r-m; r-m less than one third as long as dm-cu.

Abdomen: Syntergite 1–3 petiolate, tergites 1–2 parallel-sided, tergite 3 twice as wide at apex as base. Syntergite 1–3 densely microsculptured, sculpturing forming transverse ridges on tergite 1, sparsely tomentose. Abdominal tergites medium brown, distal segments slightly darker to dark brown. Tergite 4 separate from tergite 3.

Female terminalia: Four spermathecae in two pairs, each pair tightly appressed along broadest surface so as to seem like a single structure, each spermatheca forming half an oval circled with grooves and with a smooth, cylindrical cap at tapered end.

Male terminalia: Tergite 5 with ventrolateral margins modified, left margin developed as a single, broad, rounded lobe; right margin with a long, dark, inflexed, narrowly rounded posteroventral process and a simple short anteroventral process. Spiracles 5 and 6 in tergite, left spiracle 5 high above ventral margin, right spiracle 5 at margin; left spiracle 6 above margin, right spiracle 6 close to margin. Sternite 4 divided into a pair of broadly separated, small, triangular plates, sternite 5 transverse and very short, largely desclerotized except bristle bases, sternite 6 with a large, convex left lateral sclerite, a similar but much smaller right lateral sclerite, and 7–8 minute, bristle-bearing sclerites in between. Synsternite 7+8 with long lateral apodemes, ventral part broad, left spiracle more dorsal than right spiracle. Epandrium longer than wide. Cercus 3X as long as wide; surstylus elongate and slender, narrowest near middle, apical half slightly curved medially. Hypandrium with three pairs of breaks or weakenings: first between basal U-shaped portion and base of hypandrial arms, second between hypandrial bridge and mesal base of each hypandrial arm, third near middle of each hypandrial arm posterior to ventral hypandrial lobe. Anterior U-shaped portion of hypandrium robust, without anterior apodeme. Hypandrial bridge not unusually broad. Ventral hypandrial lobes slender, with round, setose apex. Posterior part of hypandrial arm broad, flat, truncate. Pregonite short, multi-angled. Basiphallus with a long-cylindrical base, distally greatly expanded with left distal corner produced into a broad, straight-sided, partly translucent lobe. Distiphallus complex, directed sinistrally, with a short basal part and a broad distal part made up of several lamellae.

TYPE MATERIAL: Holotype ♂ (type number 16470, California Academy of Sciences, San Francisco; not examined): MEXICO. San Luis Potosí, Tamazunchale , 23.xi.1946, “probably collected by” E.S. Ross, E.C. van Dyke & F. Skinner.

MATERIAL EXAMINED: COSTA RICA. “ Surrubres ” [= Surubres], no date or collector (1♀, USNM) ; Higuito, San Mateo, P. Schild (no date; one specimen with manuscript holotype label “ Syringogaster achetomelena Steyskal ”) (2♂, 3♀, USNM) ; Guanacaste, Nandayure, Cerro Azul , 1018 m, 4–5.ii.2003, W. Porras & D. Briceño, L_N_214769_397000, #73263 (1♂, 1♀, INBC) . EL SALVADOR. San Salvador, 4.iv.1958, O.L. Cartwright (2♀, USNM) . GUATEMALA. Obispo , La Providencia, iv.1916, J.M. Aldrich (1♂, 2♀, USNM) ; Petén, 2 km E Tikal , 27.xii.1988, J. LaSalle (1♂, CSCA) ; Tikal ruins, 2.ix.1972, G.F. & S. Hevel (1♀, USNM) ; Los Amates , 18–28.ii.1905, J.S. Hine (1♂, AMNH) . MEXICO. Veracruz, Acayucan , 23.x.1957, B. & K. Dreisbach (1♂, 1♀, USNM) ; Ocotal Chico , 4–5.v. 1985, 600 m, W.N. Mathis (1♀, USNM) ; Chiapas, 32 mi W San Cristóbal, Jct 190-195 Hwys , 8.v.1969, H.J. Teskey (1♂, CNCI) ; Tabasco, 8 km SW Teapa , 6.v.1985, W.N. Mathis (1♂, USNM) .

COMMENTS: Although the type was not examined, Feijen’s thorough illustrations leave no doubt as to the identity of this species, which is in any case the only member of the genus to range north to Mexico. Syringogaster subnearctica is easily distinguished from the closely related S. brunnea by its dark thorax. Feijen (1989) states that S. subnearctica differs from related species (including brunnea) by the absence of ocellar bristles, but in fact S. brunnea also lacks ocellar bristles. Feijen was presumably basing his comments on S. brunneina , a then undescribed species easily confused with S. brunnea although it has ocellar bristles.