Syringogaster craigi Grimaldi, 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 : 75-79

Syringogaster craigi Grimaldi , new species

Figs. 68–73; Plate 7B

DIAGNOSIS: Distinguished from S. miocenecus , also in Dominican amber, by the differences given in the diagnosis above.

DESCRIPTION: Based on holotype male. General coloration: Head and thorax (including petiolate segment) dark brown to blackish brown; abdomen with anterior segments light, grading into darker brown apicad. Legs light brown, graded on basitarsus to light tan/yellow. Tarsi 2–5 light.

Head with frons long, flat, length nearly equal to length of head; occipital foramen produced into short cervical collar approximately same length as pronotum. Ocellar triangle obscured by white flocculence. Frons with one pair each of thick, black ocellar and outer vertical setae; ocellars slightly shorter than outer verticals. Eyes large, longest axis of eye aligned obliquely antero-posteriad; no subgenal space visible below eyes, no visible genal setae/setulae. Face short, color and ptilinal sutures obscured by white flocculence. Ocelli and ocellar setae on small ocellar mound; bases of setae very close (separated by diameter approximately equal to diameter of setal base). Apical (flagellate) portion of arista slightly longer than twice the length of flagellomere 1, short plumose/bipectinate, with eight dorsal and five ventral branches.

Thorax with color largely obscured by white flocculence, but apparently dark brown to black based on small exposed areas; length (base of cervical collar to tip of scutellum) 1.10 mm. Pronotum large, projected anteriad, forming collar with occipital foramen. Humeral carina well developed, extended from humeral lobe to midway between humeral lobe and transverse suture. Transverse suture well developed, extends to approximately one-third the width of mesoscutum. Scutellum small, evenly rounded; postnotum large, bulging, projecting slightly beyond apex of scutellum. Color of pleura obscured, but with fine, whitish macrosetae on ventral half of anepisternum and scattered on katepisternum. Many mesopleural sutures fused; proepisterna with ventral median keel-like carina running from fore coxae to midway between fore and mid coxae. Fore femur and tibia without spines; fore basitarsus with dense, fine, whitish setae along ventral surface, lengths of setae approximately 1.2–1.8X width of tarsomere. Mid femur with smooth, thin strip of cuticle ventrally on distal third (glandular area?). Sawlines present on mid and hind tarsomeres 1–3. Mid coxae with bases fused to thorax, otherwise largely membranous. Hind legs with bases contiguous medially; coxae free but small and mostly membranous, smaller than trochanter. Hind femur incrassate, swollen, lightcolored, with two longitudinal rows of thick, stout, sclerotized spines ventrally: nine spines in anterior row, five in posterior row. Hind tibia curved to fit against spinose surface of femur, with one row of spines on each side of adpressed tibia. Anterior half of hind tibia with narrow trough on ventral surface. Lengths of femora: fore 0.58 mm, mid 0.95, hind 1.00.

Wing length (tip to base) 2.72 mm; slender, length/greatest width = 4.10, largely hyaline, with infuscate areas as follows: one from apex of R 2+3 and middle of R 4+5 (darkest area on wing) graded into a band of diffuse infuscation reaching past dm-cu, one small area around crossvein r-m, and one transverse infuscation encompassing basal fork of Rs, crossvein m-cu, and CuA 2, nearly reaching wing margin. Veins and crossveins distinctly darkened in infuscate areas. Spinule-like setae absent on segment of costal vein proximal to apex of R 1; vein C ends significantly posterior to wing tip, connected to tip of M. Sc present as distinct vein, incomplete and tapered apicad, runs very close to R 1. Base of wing bare of microtrichia (as figured), microtrichia much denser over crossveins and infuscate areas. Microtrichia irregular but in rows near margins of wing and on anal lobe. Vein proportions as figured; longitudinal veins slightly sinuous. Apices of veins CuA 1 and A 1 +CuA 2 abruptly ending approximately two-thirds the distance between vein base and wing margin. Wing margin with dense fringe of fine setulae; setulae sparse on anal lobe and alula. Halter pale.

Abdomen: Approximate length (tip to base of petiole) 2.02 mm. Abdomen yellow apically, graded to dark brown apicad (particularly tergites 4, 5, and 6); epandrium and cerci yellow. Abdominal tergites largely bare, with scattered setae at posterior end. Very weak, incomplete suture between tergites 2 and 3; no such suture apparent between tergites 1 and 2 (area is well exposed). Syntergite 1–3 approximately two-thirds the abdomen length, almost parallel-sided, but not conical shaped. Spiracles difficult to observe, but one clearly in tergite 3 near anterolateral corner [spiracles in/near more terminal tergites possibly obscured by overlapping portions of these sclerites]. Lateral portions tergite 5 simple. [Terminal sternites obscured]. Epandrium small, setulose, longer than wide; cerci slightly smaller than epandrium, setulose. Postgonite apparently complex, a bilobed structure with pair of small spines, attached to body via slender stalk. Distiphallus large, bilamellate and striate, curved dorsad and sinistral [apex (e.g., distal lobes) obscured].

TYPE MATERIAL: Holotype ♂: a complete specimen nicely preserved in a piece of Miocene amber from the Dominican Republic, though with a white flocculence obscuring details of the head and thorax. Exact provenance within the Dominican Republic is unknown, the specimen was sent to the AMNH by Mr. Pat Craig. The amber piece is an irregular shape measuring 10 x 7 x 3 mm and is polished flat on opposite sides of the two broadest surfaces, to maximize a lateral view (especially the genitalia) and a dorsal view of the fly. Other inclusions in the piece include a myrmecine ant (about half the size of the fly, doubtfully a model for the fly) and clumps of whitish material from which protrude oblong structures. These are probably dipteran eggs, judging from the shape, the chorionic structure, and opercula, and were probably deposited on some decaying material. Deposited in the AMNH amber fossil collection, Division of Invertebrate Zoology.

ETYMOLOGY: Patronym for Mr. Pat Craig, who recognized the obscure family of this fly and sent it to the AMNH.

COMMENTS: See comments for previous species.