Cratotabanus asiaticus, 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 : 45-47

Cratotabanus asiaticus , new species

Figures 15 , 48

DIAGNOSIS: Separated from C. newjerseyensis by C. asiaticus having the following: larger body (12.5 mm); apices of veins Sc and R 1 gradually meeting C, not upturned; R 4 significantly less sinuous; M 1 more arched; apex of bm more acute; cell cup closed (i.e., A 1 +CuA 2 joined before wing margin); A 2 shorter, terminating abruptly; cell d slightly shorter. Distinguished from C. stenomyomorphus by having much longer vein R 1, apex extended well beyond level of cell d apex (vs. at same level). Venation otherwise very similar to that of C. stenomyomorphus (cf. fig. 16).

DESCRIPTION: Based on unique female. Body length 11.87 mm; wing length 8.75 mm; thorax length 4.22 mm; abdomen length 6.58 mm. Head: Hemispherical, with frontal half very rounded, posterior half/occiput slightly concave; eyes very large, dichoptic, completely bare, no differentiation of facets, eyes occupy nearly entire preoccipital portion of head. Frons bare, without callosities; with very small central ridge; very narrow, width ca. equal to 4× diameter of eye facet, margins virtually parallel. Ocelli large, on virtually no mound. Minute supraantennal lobe between antennal bases. Antenna: Lost past 3rd article. Antennal sockets and pedicel hardly exposed. Pedicel slightly funnel shaped, with very few stiff, short apical setae; only fragment of basal flagellomere preserved. Clypeus hidden by palps, not observable; deep parafacial sulcus present. Cheek, occiput, and postgena with dense, fine pilosity. Mouthparts: Palp 2-segmented; basal segment robust but shorter than apical segment; both palpomeres with dense, fine setae (no macrosetae); apical palp slightly arched (dorsally convex); positions of palps distorted, resting position not observable. Most of proboscis lost, remaining portions are bases apparently of labrum and perhaps laciniae or mandibles. Thorax: Dorsally light brown, pleural area mostly dark brown; scutum and scutellum devoid of macrosetae, with vestiture of extremely small, fine, decumbent setulae. Fine, long, whitish pilosity on supraalar region, ventrolateral portions of scutellum, and pleuron. Prescutellum and subscutellum present. Postmetaspiracular scale absent or possibly very small. Wing: Largely hyaline, except for very narrow pterostigmatic at apex of R 1; minute microtrichia over entire wing membrane. Wing long and slender (W/L = 0.33), apex acutely narrowed; anterior edge straight. Basicosta deeply incised, wider at base, lappetlike; C circumambient, base very thick, with fine, stiff setae, C abruptly narrowed at wing tip. Crossvein h faint; Sc straight, gradually meeting C, not upturned at tip, length 0.55× wing length; R 1 very close to Sc, length 0.70× that of wing; stem of R and entire length of R 1 with 2–3 rows of microtrichia on dorsal surface, diminished to 1 row on apex of R 1. Fork of R short, base diverging far distal to level of cell d apex; R 4 and R 5 very divergent, asymmetrical (R 4 longer), tips of both encompassing much of wing apex; R 4 slightly sinuous. Cell bm slightly longer and broader than cell br; cell d straight (not arched), narrow (W/L 0.28); vein M 1 same length as cell d, veins M 2, M 3 shorter; M veins slightly divergent; M 3 and CuA 1 convergent; stem of CuA with row of microtrichia on dorsal surface. Cell cup present, tips of CuA 2 and A 1 meeting before wing margin; vein A 2 present, short, with abrupt end. Anal lobe well developed, alula rounded and short; upper and lower calypters present, lower calypter large, subcircular. Legs: With dense vestiture of very short setulae (especially on tibiae and tarsi); coxae with fine, sparse pilosity, metacoxa without peg on anterior surface; tibial spurs 0-2-2; empodium pulvilliform, apically broader than pulvilli. Abdomen: Not particularly dorsoventrally flattened; tergites and sternites wide, with lateral margins almost meeting laterally; tergite 1 medially divided; tergites and sternites with dense, very short pilosty. Cerci 2-segmented, basal segment symmetrical, ca. twice the size of apical segment. Tergite 9 apparently not divided medially.

4+5

TYPES: Holotype, female, AMNH Bu-SE3/2.

ETYMOLOGY: “From Asia,” in reference to the continent of origin, in contrast to the other two species of the genus from the Cretaceous of South and North America.

Figures

FIG. 15. Cratotabanus asiaticus (Tabanidae), new species, holotype AMNH Bu-SE3/2. A. Base of costal region of right wing, dorsal view. B. Wing, dorsal view, with details of setulose R1. C. Area surrounding metathoracic spiracle. Note absence of postspiracular scale. D. Female terminalia, right lateral view. E. Anterior portion of head, as preserved. Apical portions of the antennae have been lost, as have the apical portion and labium + labellum of the proboscis.

FIG. 48. Cratotabanus asiaticus, new species (Tabanidae), holotype female, AMNH Bu-SE3/2. A. Habitus, right lateral. B. Detail of head and thorax, right lateral. C. Habitus, left lateral.