Stenomicra ariela, Grimaldi, 2009

Grimaldi, David A., 2009, The Asteioinea of Fiji (Insecta: Diptera: Periscelididae, Asteiidae, Xenasteiidae), American Museum Novitates 3671, pp. 1-60 : 4-5

Stenomicra ariela , new species

Figures 5 , 6

DIAGNOSIS: Easily distinguished from all other Fijian Stenomicra by the completely yellow body (only ocellar triangle dark brown), and by the male genitalia with the broad, incurved surstylus and the bulbous aedeagus.

DESCRIPTION: ThL 5 0.54 mm. Differs from S. distincta and S. tokotaai by the following features: Arista with four dorsal, three ventral branches. Basal flagellomere with pointed apex, apical tuft of setulae nearly equal in length to flagellomere. Posterior fronto-orbital seta very far anteriad on frons, past dorsal level of antennae; both FO setae appear reclinate (possibly preservational, see below). Pseudovibrissae fairly long, length nearly equal to that of posterior FO seta. Row of four long, fine acrostichals; dorsocentrals in graded series, anteriormost shortest, posteriormost dc longest (approximately 1.4X length of preceding dc). Notopleuron with four setae; dorsal two about 0.5X length of ventral ones. One katepisternal seta present, erect. Halter yellow, not white. Forefemur with two lateral rows long, erect, fine setae, plus two longer setae that project posteriad. Midfemur with ventral row of long, stiff, fine setae. Wing hyaline, rather slender and long (W/L 5 0.38); tip slightly and bluntly pointed; dorsal edge of costal vein with row of ca. 5 stout setae near junction of R 1. Cross veins rm and m-cu close together (L r-m / L between r-m and m-cu 5 0.23). Alula, anal lobe, vein A 1 +CuA 2 essentially absent. Male genitalia: Epandrium shallow, lateroventral lobes with ca. 7 large, stiff setae pointed downward; cerci largely membranous, attached to epandrium, each lobe with ca. 10 minute, spinulelike setae, one very long seta on ventral margin. Surstylus broad, curved inward and forming ventral shelf. Hypandrium a simple, flat, bilobed plate, nearly symmetrical; aedeagus bulbous, ventral portion covered with microtrichia, lateral, membranous lobe of aedeagus with microtrichia and sclerotized strip. Base of aedeagus broad, trough shaped, with two lightly sclerotized appendages (paraphyses?), left one displaced laterally, right one pointed ventrad.

TYPE: Holotype, male: FIJI: Viti Levu , VII.9.08, Nakobalevu Rd., 394 m., 18 ° 039310S, 178 ° 249550E, in rolled leaves, D. Grimaldi (no. 39: terminalia dissected). In AMNH. Known only from a unique male. The thorax and appendages are in good condition, but the eyes, face, and portion of the frons are partly collapsed.

ETYMOLOGY: From Greek and Hebrew, meaning an airy sprite, in reference to the light-colored body of this species and the floating movements of flies in this genus.

Figures

Fig. 5. Wings and details thereof of Fiji Stenomicra. A. S. ariela. B, C. S. distincta. D. S. tokotaai. E, F. S. distinctipennis.

Fig. 6. Male terminalia of Stenomicra ariela (not to same scale) A. Epandrial complex, posterior view. B. Hypandrium, aedeagus, and aedeagal sclerite.