Megaselia falciphalli, DISNEY, 2003

DISNEY, R. H. L., 2003, Tasmanian Phoridae (Diptera) and some additional Australasian species, Journal of Natural History 37 (5), pp. 505-639 : 543-545

Megaselia falciphalli sp. nov.

(figure 17)

Material

H  : male, Tasmania, Fern Tree, Grays Road , 147°15∞E, 42°57∞S (grid ref. 203474), 540 m altitude, 12 August 2000 ( R. H. L. Disney —25-43) ( TMH).

P    : 2 males, 3 females, as holotype except dates include 7 and 8 August 2000 (25-42-43) ( TMH, UMZC).

Etymology The name refers to the sickle-shaped penis.

Diagnosis

The combination of scutellum with posterior pair of bristles and a pair of minute hairs; mesopleuron with hairs and one or two differentiated bristles at rear margin; costal cilia exceeding 0.12 mm in length; hind tibia lacking differentiated anterodorsal hairs; and pale yellow haltere knobs; will take this species to couplets 13–20 on p. 203 of Borgmeier’s (1967a) keys. The combination of a costal index of 0.47–0.55; wing length <2.8 mm; unequal supra-antennal bristles; and yellow femora (apart from brown tip to hind femur); exclude the species covered by these couplets, apart from those distinguished in the key below. Labella densely spinose below in both sexes; epandrium with hairs but no differentiated bristles; costal section 1 longer than 2; third antennal segment lacking SPS vesicles; labrum darker than palps.

Male

Frons wider than long, brown, with 54–74 hairs and fine but very dense microsetae. Antials almost midway between anterolaterals and upper SAs, but slightly lower on frons than either. Upper SAs further from each other than either is from an antial, but a little closer together than either is from an AL. Lower SAs much shorter and weaker than upper pair. The median row of bristles in an irregular transverse row and almost equally spaced. With three small bristles on cheek and three strong bristles on jowl. Third antennal segment pale yellowish brown, but darker at apex. Palps paler, with five to seven bristles and half as many hairs. The subtriangular, pale orange-brown labrum with basal width at most 0.8× that of third antennal segment. Labella with brown bands dorsolaterally. Each with a band of>30 densely crowded spinules below and four pale teeth adjacent to glossa. Thorax brown, being darkest on top. Three bristles on notopleuron. Mesopleuron with 10–11 hairs and one or two short bristles (which are shorter than shortest notopleural) at rear margin. Abdominal tergites brown and with short hairs which are only a little longer at rear margins. Venter brown on sides but pale dusky yellow below, where fine hairs are present on segments 3–6. Hypopygium brown, with a yellow anal tube lightly tinged brown, and as figure 17B. Right lobe of hypandrium vestigial. Legs yellow lightly tinged brown, apart from brown tip to hind femur and dark brown dorsal edge of hind tibia. Front basitarsus slender (length about 7× breadth) and all five fore-tarsal segments with a posterodorsal hair palisade. Neardorsal hair palisade of mid tibia extends about three-quarters of length. Hairs below basal half of hind femur clearly longer than those of anteroventral row of distal half. About a dozen differentiated posterodorsal hairs on hind tibia, but uppermost four or five are weak and one situated just before apical third is more spinelike. Wing length 2.0– 2.2 mm. Costal ratios 3.05–3.71:2.49–2.85:1. Costal cilia 0.13–0.17 mm long. Sc fades away before reaching R. A well-developed hair at 1

base of vein 3. With three or four bristles on axillary ridge. Veins brown and membrane tinged brownish grey.

Female

Head similar to male except the labrum is darker, more heart-shaped, and its greatest width is nearly 1.2× that of third antennal segment; and the spinules of labella are situated more ventrolaterally. Thorax as male, except mesopleuron with 8–13 hairs and only one bristle. Abdominal tergites brown with short hairs that are only a little longer at rear margins. T 5– T 7 as figure 17A. Cerci dusky pale yellow, about 3× as long as wide and with 10 ten hairs, the posterior (inner) pre-apical being a little longer than rest. Venter brownish grey but with paler inter-segmental bands and small hairs below on segments 3–6. Sternite 7 a narrow bar, with only a few small hairs, expanding at rear end, where there are four longer hairs. The posterolateral lobes at rear of sternum 8 short, square-ended, and densely covered in small hairs plus three bristle-like hairs. Internally, Dufour’s crop mechanism is elongated (sausage shaped) and with four rectal papillae. No furca evident. Legs similar to male. Wings 2.1–2.6 mm long. Costal ratios 3.3–4.3:2.4–2.8:1. Costal cilia 0.12–0.17 mm long. Otherwise as male.

Natural history

One female had eight developing oval eggs (measuring 0.38–0.42× 0.22–0.25 mm). Another female had three mature eggs measuring 0.45–0.47× 0.33–0.34 mm.