Borneomyia Brake

Brake, Irina, 2004, Borneomyia, a new genus and two new species of Milichiidae (Diptera, Schizophora), Zootaxa 627, pp. 1-8 : 2-4

Borneomyia Brake , n. gen.

Genus nov 1, in Brake 2000.

Type species: Borneomyia tigra Brake , n. sp., by present designation.

Description: Body wholly subshiny, only mesonotum slightly more shiny. Body usually yellow with brown stripes. Antennal grooves yellow with roughly circular spot ventral to each antenna.

Head (fig. 1): Frontal triangle extending to level of middle orbital seta. Three orbital setae, posterior seta lateroreclinate, anterior 2 setae lateroclinate; two medioclinate frontal setae. One reclinate setula between posterior and middle orbital setae, one medioclinate setula each between middle and anterior orbital setae and between anterior orbital seta and posterior frontal seta, 2 or 3 medioclinate setulae between frontal setae, and one medioclinate setula ventral to anterior frontal seta; about 5–6 small interfrontal setulae, anterior setula slightly longer; additional setula between anterior interfrontal setula and anterior frontal seta. Lateroproclinate ocellar and medial and lateral vertical setae present, plus some setulae. Postocellar setae cruciate. Lunula not or only narrowly visible, apparently without setulae, merging into face. Antenna short; basoflagellomere round, about as long as pedicel; arista long (about as long as head height), long pubescent. Vibrissal angle not produced, but base of vibrissa protuberant. Vibrissa well developed, followed posteriorly by slightly smaller seta also on slight protuberance. Gena covered by several setulae. Palpus flat, elongate spatulate, with several setulae. Labellum with 4 pseudotracheae, 2 medial pseudotracheae converging towards labellum apex.

Thorax: Mesonotum about as long as broad. Chaetotaxy: 1 large postpronotal plus 1 additional seta about 0.4x length of postpronotal, 2 notopleural, 1 presutural, 1 supra­alar, 1 postalar, 1 intra­alar, and 3 postsutural dorsocentral setae, anterior dorsocentral only slightly longer than acrostichal setulae, middle dorsocentral about 0.6x length of posterior dorsocentral, acrostichal setulae in irregular rows, 1 short prescutellar acrostichal seta, 1 apical and 1 basal scutellar setae, basal seta longer than apical seta, apical setae cruciate, 1 proepimeral seta, 1 proepisternal seta, anepisternum bare, 1 katepisternal seta and row of setulae anterior to katepisternal seta from dorsal to ventral margin of katepisternum, no anepimeral seta.

Legs: Forefemur bearing posterodorsal, slightly irregular row of about 6 setae, these becoming progressively longer distally. Foretibia with 2 slightly stronger preapical setulae. Basitarsomere of foreleg with anteroventral row of setulae and a few stronger setulae ventrobasally. Midfemur in males with femoral organ anterodorsally and shortly proximal to middle (figs. 2 and 3). Femoral organ consisting of field of irregularly­placed tiny setulae of probably sensory function ( Brake 2000). Midtibia with several stronger setulae and 1 seta preapically. Hindfemur enlarged, about 1.5–1.8x as broad as fore­ and midfemur. Hindtibia as foretibia, with ventroapical comb of setulae. Basitarsomere of hindleg with several ventral rows of 3–5 setulae, with setulae flattened apically (fig. 4), and with few stronger setulae ventrobasally.

Wing (fig. 8): R4+5 and M1 parallel. Cell cup closed. Wing surface covered by numerous brown microtrichia which are about as long as costal spines.

Abdomen: Tergites with relatively sparse setulae, with setulae progressively longer posteriorly, and row of setae along posterior margins of tergites 4 and 5. Sternite 5 with row of setae, setae posterolaterally longest. Male terminalia as in fig. 7. Epandrium spherical; surstylus deeply notched at middle. Hypandrium U­shaped, not fused with phallapodemic sclerite. Pregonites bare, not fused with hypandrium, but appear to be fused with phallapodemic sclerite. Distiphallus short and glabrous, without sclerotizations.

Females differ from males in absence of femoral organ. Sternites 2­8 complete, not reduced. Ventral receptacle globular; spermathecal ducts elongate and rolled up together distally into one longish spool­like coil; sclerotized spermathecal capsules absent, distal end of spermathecal ducts surrounded by epithelial gland cells.

Etymology: The genus name is derived from the island Borneo and the Greek myia = fly, referring to the place where most of the specimens have been collected. The gender of the name is feminine.

Discussion: The new genus differs from other milichiid genera in the presence of a femoral organ on the male midfemur, in the basitarsomere of the hindleg having several ventral rows of 3–5 setulae, and in the brown spot, each, on the otherwise yellow antennal grooves.