Schlingeromyia minuta Grimaldi & Hauser

Grimaldi, David A., Arillo, Antonio, Cumming, Jeffrey M. & Hauser, Martin, 2011, Brachyceran Diptera (Insecta) in Cretaceous ambers, Part IV, Significant New Orthorrhaphous Taxa, ZooKeys 148, pp. 293-332 : 305-307

Schlingeromyia minuta Grimaldi & Hauser sp. n. Fig. 5

Diagnosis.

As for the genus.

Description.

Body length 3.0 mm, wing length 2.1 mm. Head: Large, spherical. Eyes very large, occupying most of head capsule. Eyes bare, without interfacetal setulae; no dorso-ventral or frontal differentiation of facets. Entire mesal margins of eyes above antennae are contiguous, portion of mesal eye margin below antenna also contiguous. Posterior margin of eye strongly emarginate; ventral margin of eye slightly less so. Antenna minute, length approximately equal to diameter of 2-3 eye facets; consists of small oval pedicel and minute apical style. Mouthparts vestigial. Postocciput with scattered, fine setulae. Thorax: Scutum strongly arched, very large, length of (meso)thorax 1.25 mm (nearly half the body length). Scutellum small. Position of cervical region near ventral surface of thorax. Pair of well-developed postpronotal lobes dorsal to cervical region, posterior surface of lobe slightly concave. Scutum with sparse, short setulae; scutellum with slightly thicker setulae. Legs slender, mesotibia with short pair of apical spurs; apices of tarsomeres with pair of short, thick setae. Length of basitarsomere approximately equal to that of remaining, distal tarsomeres; hind tibia expanded in width apically to approximately twice the proximal width. Pretarsus with claws large; mediolobus and pulvilli large, pad-like. Wing short and slender, length 2.10 mm, greatest width 0.75 mm; membrane with fine, faint pleating/wrinkling over apical and posterior regions, but not in closed cells [best seen in oblique views]. Calypter large, ovoid, greatest diameter 0.58 mm. All veins sclerotized, none faint. C ends at apex of R4+5; Sc short, meets C slightly distal to level of where R1 and Rs fork. R1 and Rs fork at ca. 0.4 × length of wing; stem of Rs short, approximately 0.2 × total length of Rs. Rs surrounds large r4+5 cell, near middle of which R2+3 branches off to meet C. Vein R4+5 branches off of apex of cell r4+5, apex meets C slightly posterior to wing apex; M1 also short, branching subapically off of cell r4+5. Tip of wing not encompassed by an apical fork of R4 - R5. Cell d bounded by M1 and M2; slender (ca. 0.3 × thickness of cell r4+5). Cell m3 slender, trapezoidal, with proximal end slightly opened. Cells br and bm continuous, not bissected (vein M extremely faint or lost from this area). A1 slender, meeting CuA shortly before wing margin. A2 not apparent; anal lobe of wing well developed. Calypter large, hemispherical, greatest diameter 0.25 × length of wing. Abdomen: Smaller than thorax, with six tergites visible (tergite I small, tI and tII virtually obscured in dorsal view under postnotum). Tergites entirely bare of microtrichia and setulae; glabrous [probably reflective], with cuticular microsculpture of minute hexagonal cells present. Spiracles not visible near lateral margins of tergites [in pleural membrane?]. Tergites VII-VIII apparently small [not discernable]. Two pairs of male genitalic appendages present: slender dorsal pair (probably gonostyli), thicker ventral pair (gonocoxites), plus terminal, central, membranous appendage, the phallus.

Type.

Holotype, Male, AMNH Bu332a, in Burmese amber. Paratype, AMNH Bu332b, in same piece of amber. Both specimens are entirely preserved, though slightly obscured by debris and a few small fractures. The specimens occur in a runnel-shaped piece of dark but transparent amber, 16 × 7 mm, which has been embedded in epoxy. The piece also contains 1 Coleoptera , 1 Hymenoptera ( Serpitidae ), and 6 other Diptera ( Cecidomyiidae , Empidoidea ), as well as twisted strands of spider webs. Interestingly, acrocerids are parasitoids of spiders.

Etymology.

Latin, adjective, in reference to the very small size of the species.