Syringogaster palenque 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 : 53-55

Syringogaster palenque Marshall & Buck , new species

Figs. 43–45; Plate 2F; Map 6

DESCRIPTION: Head uniformly pale reddish brown except for black ocellar tubercle. Frons including ocellar triangle tomentose; ocellar triangle strongly tapered and triangular, anterior apex rounded and separated from frontal margin by 2X scape length; remainder of frons tomentose and dull; ocellar triangle on same plane as rest of frons, flanked on each side by a row of 5–6 very small inclinate bristles. Ocellar bristles well developed. Pedicel almost entirely setulose, a small anteromedial area bare and shining. Face pale, lower part expanded and with black bristles; shining vibrissal angle with thin black bristles. Gena and subgena subequal in height at middle, gena with only fine pale setulae behind shining and sparsely setose vibrissal angle. Supracervical collar 2–3X length of pronotum, lateral carina continuous with prominent, anteriorly directed posterior tentorial pit.

Thorax: Pronotum dark dorsally and reddish laterally, very short medially. Mesonotum mostly dark excluding reddish brown postpronotum and small anterolateral area in front of humeral carina. Humeral, notopleural and supra-alar carinae well developed, the latter very large and prominent. Pleuron mostly dark brown to black excluding reddish brown propleuron and anterior part of anepisternum, shining reddish anterior part of anepisternum well demarcated from dark and tomentose posterior part; katepisternum mostly bare and shining, tomentose along anterodorsal margin and with scattered long setulae; anepimeron dull tomentose. Metathoracic spiracle prominent and long-setose, first and second prespiracular lobes small, subspiracular ridge large and divided into a shining anterior part and a tomentose posterior part. Metasternum reddish brown, postmetacoxal bridge dark reddish brown to medium brown. Fore coxa whitish, remainder of leg pale brown except for somewhat darkened tibia; all bristles pale and thin (no stout, black anteroventral spines on femur). Mid femur whitish basally, rest of femur pale brown except for more or less developed darker dorsal streak in distal 2/3; tibia yellowish, sometimes with brown basal half. Mid tarsomeres 1–3 with antero- and posteroventral sawlines. Hind femur with a narrow, indistinct white basal ring; remainder of leg orange-brown except for dark brown concave apicoventral area and sometimes brown subbasal ring. Hind femur concave and densely tomentose dorsally on distal third, convex and glabrous for balance of dorsal surface; anteroventral row of 11–14 spines extending over distal 7/10 of femur, posterior row shorter. Hind tibia with apex weakly trilobate, lobes subequal. Sawlines present on hind tarsomeres 1–3.

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 more than twice the length of bm-cu; A 1 +CuA 2 and CuA 1 each extending about 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: Abdomen strongly petiolate, syntergite 1–3 parallel-sided on at least basal half, tergite 3 twice as wide at apex as base. Syntergite 1–3 densely microsculptured, sculpturing forming transverse ridges on tergite 1, densely tomentose. Abdomen reddish brown, dark brown along posterior margins of all tergites including each of tergites 1 and 2; no suture line between tergites 2 and 3; tergite 4 separate from tergite 3.

Female terminalia: Tergite 7 with deep posteromedial emargination. Four spermathecae in two pairs, each pair close together on short ducts, touching but not fused; spermatheca smooth, broadly cylindrical, with a broad basal invagination and a small smooth, cylindrical cap (evagination) distally, cap about 0.25X spermathecal diameter.

Male terminalia: Tergite 5 with ventrolateral margins unmodified, ventrolateral margin of tergite 6 with a tapered anteroventral corner; spiracles 5 and 6 in tergite close to lateral margin. Membranes of abdominal segments 4 and 5 densely covered with stout black spinules, sternite 5 divided into two small, widely separated round sclerites, each with 3 or 4 bristles on each sclerite; sternite 6 short and transverse, irregularly interrupted several times. Synsternite 7+8 with ventral part broad, right spiracle lateroventral and left spiracle lateral. Epandrium longer than wide. Cercus and surstylus narrow and elongate, cercus 3X as long as width, surstylus 4X as long as greatest width, slightly curved and gradually tapered towards apex; outer surface of surstylus with long hairs some of which are almost as long as the surstylus. Hypandrium with two pairs of breaks or weakenings: first between basal U-shaped portion and base of hypandrial arms, weakening between hypandrial bridge and mesal base of each hypandrial arm secondarily closed but still with an anterior and a posterior incision, second near middle of each hypandrial arm posterior to ventral hypandrial lobe. Anterior U-shaped portion robust, anterior apodeme hardly developed. Hypandrial bridge very broad and considerably projecting posteriorly below cerci, medial length almost as great as width. Posterior part of hypandrial arm broad, with broad, rounded ventral lobe; ventral hypandrial lobe elongate, distally long-setose. Pregonite with longitudinal dorsal, ventral and medial carinae. Basiphallus with apex moderately expanded, bearing posteriorly directed finger-like lobe on left side. Distiphallus relatively short, with a basal part made up of several plates including a large, cup-shaped left basal sclerite; distal part with a long sickle-shaped, sclerite directed medially from right side.

TYPE MATERIAL: Holotype ♀ ( DEBU): ECUADOR. Pichincha Prov., 47 km S Sto. Domingo, Río Palenque Biological Station , 250 m, 17–25.ii.1979, S.A. Marshall . Paratypes: COLOMBIA. Montería , iii.1958, M. R . Wheeler (1♂, badly damaged, lacking head and most legs, AMNH). ECUADOR. Guayas, Naranjal, xii.1955, Levi-Castillo (♀, head missing, USNM); Puruguay , house of Alfredo Paliz , 1°27.52’S, 79°12.33’W, 690 m, 5–7.iii.2006, secondary forest and garden, yellow pan traps around the house, M. v. Tschirnhaus, “EC1808” (1♀, DEBU) .

ETYMOLOGY: This species is named for the biological reserve at Río Palenque, where the senior author collected the holotype in 1979 (see above).

COMMENTS: Its unusually dark thorax (especially the mostly dark mesonotum) distinguishes S. palenque from the closely related S. brunneina . Syringogaster lopesi has a similar thoracic color pattern, including the pale anterior anepisternum and dark posterior anepisternum, but this species is easily distinguished from S. palenque by the presence of fore femoral spines. The male of S. palenque is distinctive for a number of postabdominal characters including the narrow, tapered, long-setose, surstylus; extremely wide hypandrial bridge; ventral lobe of posterior part of hypandrium; slender, posteriorly directed lobe on left side of apex of basiphallus (directed posterolaterally in S. brunneina ), and sickle-shaped process near apex of distiphallus.

Syringogaster palenque is one of only three South American species of Syringogaster known from west of the Andes (the others are the widespread S. rufa and S. brunnea ). Eight species of Syringogaster have been recorded from Ecuador east of the Andes. The male paratype of S. palenque is one of only five Syringogaster specimens we have seen from Colombia. The other specimens we have seen from Colombia, including one collected at the same time and place as the holotype of S. palenque , are all S. brunneina . It is not unusual to find different species of Syringogaster together, and we recently observed S. brunneina on the same group of leaves as S. brunnea in Costa Rica.