Megaselia nudilobulus, DISNEY, 2003

DISNEY, R. H. L., 2003, Tasmanian Phoridae (Diptera) and some additional Australasian species, Journal of Natural History 37 (5), pp. 505-639 : 571-573

Megaselia nudilobulus sp. nov.

(figures 32, 47C)

Material

H  : male, Tasmania, Hobart, Battery Point, De Witt Street , garden, 1–11 January 1992 ( R. H. L. Disney —25-39) ( TMH).

P    : male and female as holotype except (25-6, 25-38) ( UMZC); male, Fern Tree, Grays Road, 147°15∞E, 42°57∞S (grid ref. 203474), 540 m altitude, 8 August 2000 ( RHLD —25-42) ( UMZC) .

Etymology The named refers to the bare left lobe of the hypandrium.

Diagnosis

The combination of scutellum with pair of bristles and anterior pair of minute hairs; mesopleuron with hairs but no differentiated bristles; costal index 0.43–0.48; no differentiated anterodorsal hairs on hind tibia; brown halteres; dense microsetae on frons; yellowish brown palps; and costal cilia about 0.1 mm long; take this species to couplet 15 (of group IV) or 2 (of group V) on p. 206 of Borgmeier’s (1967a) keys. Like M. fortipes Borgmeier it has a dilated front basitarsus, but its brown (not yellow) femora will immediately distinguish it. The long anal tube will at once distinguish it from M. turbidipennis Borgmeier. The dilated front basitarsus, with some hairs of ventral face reduced to short blunt spinules, will distinguish M. nudilobulus from all subsequently decribed species that run to these couplets. Brown third antennal segment lacks SPS vesicles; palps with five or six strong bristles plus as many small ones; labella almost devoid of small spinules below; thorax and abdominal tergites brown; notopleuron with three bristles; epandrium with one bristle and a few hairs each side; hairs below basal half of hind femur a little shorter than anteroventral hairs of distal half, but distinctly more robust; vein 3 with zero to one minute hairs at base; and Sc not reaching R.

1

Male

Brown frons broader than long. Supra-antennal bristles strong and subequal. Anterolaterals about level with upper SAs. Antials slightly lower and a little closer to ALs than to upper SAs. Pre-ocellars a little closer together than either is from a mediolateral, and all four bristles in an almost straight transverse row. Three to five bristles on cheek and three longer ones on jowl. Yellowish brown labrum about three-quarters width of third antennal segment. Labella whitish and each with a brown band dorsally. Ten or 11 hairs on mesopleuron. Hairs of abdominal tergites sparse and a little stronger at rear margins, especially on T 6. Hairs below segments 3–6 of brownish grey venter situated on subcircular brown discs. Hypopygium brown, with paler anal tube, and as figure 32B. Lobe from rear of left side of hypandrium bare distally. Front tarsus as figure 32A. Near-dorsal hair palisade of mid tibia extends not quite two-thirds of length. Hind tibia with 13–17 differentiated posterodorsal hairs. Wing 1.3–1.6 mm long. Costal ratios 2.8–3.5:1.1–1.7:1. Veins brown. Membrane lightly tinged grey. Two or three axillary bristles a little longer than costal cilia of section 3.

Putative female

Head similar to male, except bristles of median row almost equally spaced; brown labrum about 1.3× as wide as third antennal segment. Fourteen hairs on mesopleuron. Abdomen with brown tergites with small hairs, which are only a little longer at rear of T 6. Widths of tergites progressively diminish from T 2 to T 6, and T 5– T 6 as figure 47C. Venter brownish grey, with small hairs below segments 3–6. Cerci light brown and almost twice as long as broad; with about six hairs, of which the posterior (inner) pre-apical is conspicuously longer than rest. Posterolateral lobes of sternum 8 not protruding rearwards, with short submarginal hairs, several shorter hairs in front of these, and relatively sparse small microsetae. Internally, Dufour’s crop mechanism elongated, with widest point about two-thirds from front and posterior end rounded but slightly truncated. With three rectal papillae and no sclerotized furca. Legs similar to male. Wing 1.60 mm long. Costal index 0.47. Costal ratios 3.21:1.29:1. Costa cilia 0.11 mm long. Otherwise as male.