Pioneeria bombylia, 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 : 67-69

Pioneeria bombylia , new species

Figures 23 , 55

DIAGNOSIS: As for genus, by monotypy.

DESCRIPTION: Based on probable female. Thorax length 2.92 mm; head width 1.74 mm; head length 0.88 mm; wing length 6.44 mm. Head: Roughly hemispherical in shape, anterior half convex, posterior half flattened and concave. Eye large, bare, no differentiation of facets; eye occupying all of lateral, much of dorsal and ventral surfaces of head; posterior edge of eye not emarginate; eye without fine transverse line through middle; no emargination near antennal base. Ocelli present, but small; ocellar triangle small, barely raised above surface of vertex. Frons (female?) well developed, width 0.16× that of head, lateral margins diverging slightly anteriad. Face and clypeus steeply recessed into oral cavity immediately ventral to antennal bases, forming ceiling to proboscis. Postgena deeply sunken, forming deep concavity into which neck inserts; postgena rimmed by pilosity of fine, long, golden setae. Gena pilose, with brush of long, fine setae. Occiput slightly concave posterior to frons, slightly bulging posterior to eyes. Occipital foramen not visible. Antenna: Cylindrical, apically tapered. Scape cylindrical, 2× length of pedicel; pedicel very slightly wider at apex, with apical ring of fine setae; flagellum with 3 definite articles, basal article 2× length of distal articles combined, with faint appearance of vestigial segments; 3rd flagellar article half the size of 2nd; minute stylus present, apical. Mouthparts: Proboscis short, projecting forward, prelabellar portion recessed into oral cavity; labellum exposed, projecting beyond frontal surface of eyes. Labium short, broad, width 0.7× the length, with long, fine pilosity. Lacinia long, laterally flanking labium; tip blunt, reaching to middle of labellum. Labellar lobes rounded, fleshy, setose, with 8 pseudotracheae. Thorax: Relatively long and narrow in dorsal view, narrower than head. Neck long, dorsally with long, fine, stiff setae; 2 paramedian groups of 6–7 longer setae anteriorly, 4–5 shorter setae near middle of neck; cervical setae point backward; neck laterally with brush of fine, long, golden setae sticking out laterally. Most of scutum and pleura covered with fine, golden pilosity; pilosity longer on pleural, notopleural, supraalar areas, posterior margin of scutum, postpronotal lobes, and posterolateral margin of scutellum. Notopleural area with 4 thick, whitish macrosetae (bristles), 1 such macroseta on supraalar area. Laterotergite/anatergite with long, fine pilosity. Transverse suture short, entirely vertical on lateral surface of scutum; scutum pinched in near middle at transverse suture. Wing: Slender, W/L 0.35. Basicosta light, well developed; C circumambient, black proximally, greatly thinned posterior to R 4 apex. Crossvein h faint; small, faint crossvein sc-r present. Sc complete, sclerotized, apex ending at midwing length. R-R 1 thickest, most heavily sclerotized vein, length 0.65× that of wing; faint pterostigmatic area between apical third of R 1 and C. R 2+3 upturned at apex, fork of R 4+5 asymmetrical, branch of R 4 longer and sinuous, apices encompassing wing tip. Branches of M 1 and M short, attached to apex of cell d; Y-juncture of M 1 -M 2 weakened; CuA 1 attached near base of cell d; cells br and bm nearly equal in length; apices of CuA 2 and A 1 meet at wing margin (cup closed); vein A 2 present, but nebulous; anal lobe well developed; alula shallow; upper calypter well developed. Legs: Bases of all coxae closely situated, coxae suspended beneath thorax (not projecting forward or laterally). All coxae with brush of fine, long, golden setae, on anterior surface of procoxa, lateral surfaces of meso- and metacoxae. Femora with fine, decumbent setae, length metafemur> meso> profemur. Mesotibia with dorsolongitudinal row of 5 short, spinelike setae, 3 such setae ventrally; protibia without spinelike setae [metatibia and metatarsus lost]. Tibial spurs 0-2-?. Basitarsomere slightly longer than distal tarsomeres combined. Pretarsal structures small, pulvilli small, empodium setiform. Abdomen: Slender, no wider than thorax in dorsal view. 7 tergites preserved, tergites ≥ 8 lost at surface of amber. Tergites 2–7 with dense vestiture of fine, decumbent setae; tergites wrapped laterally, lateral margins of tergites and sternites nearly meeting; tergite 1 with long pubescence. Sternites well developed. Terminalia: Lost at surface of amber.

TYPE: Holotype, sex unknown (probably female), AMNH Bu-SE2/9.

ETYMOLOGY: Taken from the stem of the name Bombyliidae .

COMMENTS: The fly is in a dark piece of amber retaining its natural oval outline, 15 × 32 mm, slabbed to 5 mm thickness. Surface of the amber is reddish, with a reddish coating over the fly (nascent pyritization), but the amber has excellent clarity. Apex of the abdomen and some tarsi were lost at the surface of the amber. Syninclusions are a thrips (Thysanoptera) and Ceratopogonidae (Diptera) .

Figures

FIG. 23. Pioneeria bombylia (Bombyliidae), new genus and species, holotype, AMNH Bu-SE2/9. A. Wing. B. Antenna, lateral view. C. Head and thorax, dorsal view. D. Detail of cervical area, showing setation and pilosity. E. Detail of ventral portion of head, with mouthparts.

FIG. 55. Pioneeria bombylia, new genus and species (Bombyliidae), holotype AMNH Bu-SE2/9. A. Habitus, dorsal. B. Left wing. C. Head and thorax, dorsal view.