Megaselia richardsoni, DISNEY, 2003

DISNEY, R. H. L., 2003, Tasmanian Phoridae (Diptera) and some additional Australasian species, Journal of Natural History 37 (5), pp. 505-639 : 578-580

Megaselia richardsoni sp. nov.

(figure 36B)

Material

H  : male, Tasmania, Fern Tree, near Hobart, Grays Road , at window of builder’s shed, 22 September 1998 ( R. H. L. Disney —25-28) ( TMH).

P    : male, as holotype except 18 September 1998 (25-23) ( UMZC) . Male, Mount Field National Park , Russell Falls, 26 December 1991 ( RHLD —25-5) ( UMZC) . Male, Hobart, Battery Point, De Witt Street, garden, 1–11 January 1992 ( RHLD —25-39) ( TMH) ; male, Sandy Bay , Acushla Court, 23–24 September 1998 ( RHLD —25-30) ( UMZC) .

Etymology Named after Gavin Richardson, colleague of John Hebblewhite.

Diagnosis

The combination of anterior pair of small hairs and two bristles on scutellum; mesopleuron with 4–10 hairs, but no differentiated bristles; costal index 0.44–0.49; hind tibia lacking differentiated anterodorsal hairs; haltere brown; costal section 1>2+3; costal cilia <0.13 mm long; frons with dense microsetae; and palps brown; takes this species to couplets 13–15 on p. 206 of Borgmeier’s (1967a) keys. M. malaisei Beyer is clearly larger (female wing> 3 mm long) and M. politiceps Borgmeier is smaller (male wing <1.3 mm), the wing of M. richardsoni males being 1.3–1.9 mm. Furthermore, M. politiceps has a glossy frons (=sparse microsetae). The somewhat dilated front basitarsus, with rows of hairs below reduced to short spinules, means it resembles M. fortipes Borgmeier , which is immediately distinguished by its yellow femora (apart from the dark tip to hind femur). The femora of M. richardsoni are brown. The last feature and the hypopygium will distinguish it from subsequently described species running to these couplets. Near-dorsal hair palisade of mid tibia extends almost two-thirds of length; small hair at base of vein 3; <10 hairs and bristles on left face of epandrium plus a tuft of small hairs at posterolateral extremity; left lobe of hypandrium well developed.

Male

Frons brown and broader than long. Lower supra-antennal bristles robust, but distinctly shorter than upper pair. Antials level with upper SAs, but distinctly lower than anterolaterals, and situated midway between the two or a little closer to ALs. Pre-ocellars slightly further apart than either is from a mediolateral bristle, and almost level with latter or slightly lower on frons. Four or five cheek bristles and four to six stronger ones on jowl. Dark brown third antennal segment lacks SPS vesicles. Yellowish brown palp with up to a dozen bristles. Yellowish brown labrum only about 0.6× as wide as third antennal segment. Labella pale with dusky tinge and darker dorsolateral bands, and with few spinules and hairs below. Thorax brown, being darkest on top. Notopleuron with three bristles. Abdominal tergites dark brown with evident hairs, which are strongest at rear margins (figure 36B). Venter brownish grey, with conspicuous hairs below segments 3–6 and smaller hairs below 2. Hypopygium brown, including paler anal tube and as figure 36B. Longer hairs by differentiated bristle on epandrium variably more bristle-like in some specimens. Legs brown, but front pair a little paler. Front tarsus with posterodorsal hair palisades on segments 1–4 only and 4 a little shorter than both 3 and 5. Hairs below basal half of hind femur subequal in length to those of anteroventral row of distal half, but a little finer. Hind tibia with 15–20 differentiated, but fine, posterodorsal hairs. Wing 1.3–1.9 mm long. Costal ratios 2.4–4.7:1.2–2.3:1. Costal cilia 0.10–0.12 mm long. Vein Sc ends well, before R. Vein 3 with small hair (or rarely

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two) at base. Axillary ridge with two bristles, which are at least as long as costal cilia. Veins brown. Membrane tinged grey.