Syringogaster figurata 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 : 43-46

Syringogaster figurata Marshall & Buck , new species

Figs. 37–39; Plates 3F, 6B; Map 7

DESCRIPTION: Head pale brown to orange except dark ocellar tubercle and occiput (excluding median occipital sclerite). Vertex almost straight, very weakly convex at middle. Ocellar triangle shining, bordered on each side by a row of four small inclinate bristles; almost parallel-sided on upper part, lower third strongly tapered to point, anterior apex separated from frontal margin by 2X scape length; remainder of frons tomentose and dull. Ocellar bristles strong. Anteromedial surface of pedicel shining. Parafacial with a few fine brown hairs along inner margin; shining vibrissal angle without bristles. Subgena slightly higher than gena at middle, gena with only fine pale setulae. Supracervical collar strongly developed, twice as long as pronotum dorsomedially.

Thorax: Pronotum orange, with a strong transverse carina on each side, medially with two dark diagonal lines. Thorax orange except for black, subquadrate humeral pit, humeral carina, small scutal spots opposite anterolateral corners of scutellum, posterior margin of katepimeron, metapleuron (including postmetacoxal bridge) and metasternum. Notopleural carina distinct. Anterior part of scutum (in front of humeral carina) and most of postpronotum shining in contrast to tomentose posterior part. Upper posterior corner of anepisternum with a very small patch of tomentum; lower anepisternum, katepisternum and anepimeron with a few fine bristles; mesopleuron otherwise shining and bare. Anterior prespiracular process shining black, forming a narrow carinate tooth extending posteriorly; posterior prespiracular process twice as large as anterior process, forming a strong, bare triangular lobe along anterior face of spiracle. Subspiracular ridge black, weakly developed, with a low, bare anterior lobe and a dorsally tomentose, ventrally shining posterior lobe. Fore coxa, trochanter and base of fore femur white, otherwise fore leg yellow. Anteroventral margin of distal part of fore femur with a row of 7–10 (14 in one specimen) short, stout black bristles; other fore leg bristles pale. Mid femur white basally, rest of leg pale brown to yellow. Mid tarsomeres 1–3 and basal half of tarsomere 4 with antero- and posteroventral 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 and shining on dorsal surface; ventral surface with two rows of stout bristles, anterior row of 9–13 bristles extending over distal 2/3 of femur, posterior row shorter. Hind tibia with apex with anteroventral corner weakly produced. Sawlines present on hind tarsomeres 1–4.

Wing clear with a very narrow apical infuscation, dark patches over all crossveins, and a large oval discal band extending from below apex of R 2+3 to dm-cu. Fork of CuA usually at level of bm-cu, sometimes distal of bm-cu by up to 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 of almost uniform width beyond r-m, not abruptly tapered to r-m; r-m at least half as long as dm-cu.

Abdomen: Abdominal tergites 1–6 largely shining. Syntergite 1–4 gradually increasing in width from base to apex of tergite 2, width at apex of tergite 3 3X width at base, length of tergites 1–3 2X width at apex; bare except for scattered setulae, anterior half with indistinct longitudinal wrinkling. Background color of abdomen orange-yellow, tergite 2 narrowly dark brown medially, tergite 3 broadly black medially and along anterior and posterior borders; tergite 4 black on anterior half and narrowly dark brown medially. Tergite 4 fused to syntergite 1–3. Tergite 5 yellow with a median longitudinal brown strip; female with apical tergites brown and cerci yellow.

Female terminalia: Four spermathecae in two pairs, each pair short-stemmed but distinctly separate; spermatheca dark, acorn-shaped, ringed by grooves and with a broad, conical cap.

Male terminalia: Tergites 5 and 6 brown, unmodified, ventrolateral margins straight; spiracles in membrane. Epandrium dark brown to pale brown, surstylus pale. Sternites pale, 1–4 very narrow, 5 and 6 wide but very short, entire, sternite 6 contiguous with but free from complete ring formed by synsternite 7–8. Left spiracle 7 considerably more dorsal than right spiracle; sternite 8 pale brown and shining dorsally. Epandrium much wider than long. Cercus small, much shorter than the large mitt-shaped surstylus, latter with two long apical hairs that are about half as long as surstylus. Hypandrium without internal interruptions or articulations; anterior U-shaped portion forming simple ventral band with small anterior apodemes; hypandrial bridge narrow. Pregonite large and broad, ventral hypandrial lobe short and stout, with long-setose apex. Phallapodeme narrow and simple, without conspicuous posterolateral plates. Basiphallus elongate, narrowly cylindrical at base but expanded apically; distiphallus complex, basal part long and strongly curved up left side of postabdomen, apex funnel-like with spinulose anterior membrane and finely striate posterior part; narrow median forked sclerite present, lower prong slender, finger-like.

TYPE MATERIAL: Holotype ♂ ( INBC) : COSTA RICA. Puntarenas, Osa Peninsula , 2.5 km S Rincón, ~ 50 m, 8°42’1”N, 83°30’50”W, 10–11.viii.2001, treefall, yellow pans, M. Buck, debu00188605 . Paratypes: COSTA RICA. Same data as holotype, 1♀ ; same data except yellow pans by stream, 1♀ ; same data except rain forest sweep, 3♂ ; same locality, 10.viii.2001, S.A. Marshall (1♂, DEBU) ; Puntarenas, Golfo Dulce , 3 km SW Rincón, 10 m, vi–viii.1989, P. Hanson (1♂, AMNH) ; 24 km W Piedras Blancas , 200 m, 11.v.1989, P. Hanson (1♀, DEBU) ; Manuel Antonio N.P., 23–28.viii.1986, coastal rainforest, L. Masner (1♂, CNCI) ; 3 km SW Rincón , 9°55’N, 84°13’W, 10 m, x–xii.1990, malaise trap, P. Hanson (3♂, INBC) ; San José, 16 km NNE Quepos, San Carlos, RiosParaisos Biological Reserve, Pecarí Stn. , 400 m, 9°33’53”N, 84°7’32”W, 12–15.iv.2006, pans in fresh treefall litter, S.A. Marshall (1♀, DEBU) ; Reserva Biológica Carara, near Río Grande de Tárcoles , 14.xi.1989, Grimaldi & DeVries (2♂, AMNH) ; Estación Esquinas, 0 m, Península de Osa , 8–27.xi.1992, A. Gutiérrez, L_S_301400_542200 (1♂, INBC) ; Estación Quebrada Bonita, 50 m, Reserva Carara , 1–29.vii.1992, R. Guzmán, L _N_194500,_469850 (1♂, INBC) ; Rancho Quemado, Península de Osa , 200 m, 8–28.x and 12–30.ix.1993, A.H. Gutiérrez & A. Marín, L_S_292500_511000 (3♀, INBC) ; Estación Sirena , 1–100 m, ix.1993, G. Fonseca, L_S_270500_508300 (2♀, INBC) ; Higuito , San Mateo, P. Schild (43♀ ♂, USNM) .

ETYMOLOGY: Syringogaster figurata is a Steyskal manuscript name derived from the Latin for form or shape, and presumably referring to the characteristically shaped pattern of dark pigmentation on abdominal tergites 3 and 4.

COMMENTS: This species is extremely similar to the South American S. plesioterga from which it can be separated by the characters mentioned in the key. The male genitalia of both species are nearly identical except for the forked process of the distiphallus, which has a slender and finger-like ventral, posteriorly directed prong (visible below the posterior, finely striate area in left lateral view; this structure is broader and triangular in S. plesioterga ). Syringogaster figurata appears to be widespread and relatively common at lower elevations near the Pacific coast of Costa Rica, but it has not yet been collected outside Costa Rica. Syringogaster plesioterga is known from Peru and Ecuador.