Hirmoneura zigrasi, Grimaldi, 2016

Grimaldi, David A., 2016, Diverse Orthorrhaphan Flies (Insecta: Diptera: Brachycera) In Amber From The Cretaceous Of Myanmar: Brachycera In Cretaceous Amber, Part Vii David A. Grimaldi, Bulletin of the American Museum of Natural History 2016 (408), pp. 1-132 : 52-53

Hirmoneura zigrasi , new species

Figures 17B , 49E–G

DIAGNOSIS: Differs from H. caudoprima by: smaller size, wing length 7.5 mm (vs. 8.7 mm), female cerci short; and various details of venation: cell br shorter (0.36 length of wing, vs. 0.51), diagonal vein near middle of wing (vs. more distal), apices of longitudinal veins slightly less convergent; forked portion of R 3-5 slightly longer (0.34× length of wing, vs. 0.26×); veins comprising diagonal vein are less aligned; cells d1 and d2 slightly shorter. Much larger in body size than H. aff. richterae in Burmese amber, cell cup not closed.

DESCRIPTION: Based on partial female specimen that is missing head, right ventrolateral portion of thorax, and most of legs except left meso- and metafemora. Thorax + abdomen length 8.5 mm (including cerci), thorax length 3.07 mm, wing length 7.5 mm; abdomen length 5.54 mm. Head: Lost at surface of amber with exception of thin sliver of posterior margin of left eye and margin of bordering occiput; no pilosity on preserved facets. Thorax: Robust, slightly dorsally flattened, with very short fine setae; small tufts of fine, light pilosity in supraalar region, otherwise body without long, dense, fine pilosity. Scutum with pair of very shallow, faint, paramedian grooves on anterior half, to level of transverse suture; transverse sutures deep, extend medially for 2/3 width of scutum. Postalar walls protuberant, forming calli. Wing: Long, slender, W/L 0.30, anterior and posterior margins almost parallel; membrane entirely hyaline, microtrichia on membrane extremely fine. Sc 0.73× length of wing, gradually meets C, apex slightly upturned. Vein h slightly apical to level of MA. R 1 very close and parallel to Sc, virtually straight; apices of veins R 1, R 2, R 3+4, R 5 virtually parallel, hardly convergent apicad. Diagonal vein well formed, running through middle of wing, with several small crossveins; no apical radial-medial cells present. Cell br long, 1.53× length of cell bm, more slender than bm. Cell cup not closed (CuA 2 apex does not meet A 1 before wing margin). CuP well defined, anal lobe virtually absent; alula present but shallow. A 2 not apparent. Legs: (Largely lost in unique specimen). Abdomen: Slightly compressed dorsoventrally, length 1.75× that of thorax; abdomen tapered in width apicad, tergite 0.21× width of tergite 1. Tergites and sternites well developed, edges meeting laterally. Female cerci slightly elongate, length ca. 2.2× width, not developed into swordlike oviscapt. Distal margin of female sternite 9 with two small paramedian lobes with fine setae.

TYPES: Holotype, female, JZC Bu-169.

ETYMOLOGY: Patronym for James Zigras, for his generosity over the years in making a wide array of Burmese amber species available for study.

COMMENTS: A partial specimen missing the structures described above; the remaining portions are hollowed and cleared (improving resolution of sutures, etc.), but the amber is translucent and obscures some details.

Figures

FIG. 17. Wings of three species of Hirmoneura Meigen (Nemestrinidae) in Burmese amber. A. Hirmoneura caudiprima new species, holotype, AMNH Bu-SE17. B. Hirmoneura zigrasi, new species, holotype, JZC Bu-169. C. Hirmoneura aff. richterae Mostovski and Martínez-Delclòs, HP-B-6084.

FIG. 49. Hirmoneura spp. (Nemestrinidae). A–D. Hirmoneura caudiprima, new species, holotype female, AMNH Bu-SE17. E–G. Hirmoneura zigrasi, new species, holotype female, JZC Bu-169. A. Habitus, dorsolateral. B. Head, dorsolateral. C. Female terminalia, showing long cerci. D. Right wing. E. Habitus, dorsal. F. Habitus, left lateral. G. Habitus, ventral.