Megaselia filiciarboris, DISNEY, 2003

DISNEY, R. H. L., 2003, Tasmanian Phoridae (Diptera) and some additional Australasian species, Journal of Natural History 37 (5), pp. 505-639 : 548-550

Megaselia filiciarboris sp. nov.

(figure 19)

This species has been collected in Tasmania and Western Australia.

Material

H  : male, Tasmania, Fern Tree, Grays Road , 147°15∞E, 42°57∞S (grid ref. 203474), 540 m altitude, 7 August 2000 ( R. H. L. Disney —25-41) (TMH).

P    : male, Western Australia, 33°22∞S, 116°05∞E, 10–12 October 1996 (Cindy Brown, 25-12) (UMZC).

Etymology The name refers to the type locality, Fern Tree.

Diagnosis

The combination of scutellum with posterior pair of bristles and anterior pair of hairs (at most as long as those at rear of scutum); mesopleuron with 8–10 similar hairs; costal index>0.5; no differentiated anterodorsal hairs on the hind tibia; pale yellow haltere knob; forked vein 3; two pairs of unequal supra-antennal bristles; costal cilia> 0.15 mm long; and costal sections 1 and 2 subequal; takes this species to couplet 10 on p. 206 of Borgmeier’s (1967a) keys, to M. agnatoides Beyer. It is immediately distinguished from the latter by the suddenly narrowed base of the male hind femur and larger size (wing length <1.5 mm in Beyer’s species but> 2 mm

in new species). Additional diagnostic features are the enlarged labella, which are densely spinose below; and narrow, curved, left process of the hypandrium.

Male

Frons brown, broader than long, with 36–40 hairs, and very fine but dense microsetae. Lower supra-antennal bristles about two-thirds as long as upper pair and only about two-thirds of distance apart. Antials a little closer to anterolaterals than to upper SAs and all four bristles in an almost straight transverse row. Preocellars a little closer together than either is from a mediolateral bristle and slightly lower on frons than latter. Three or four bristles on cheek and three longer and stronger ones on jowl. Third antennal segment brown, but not dark, and lacking SPS vesicles. Palps yellow and a little expanded ventrally; with seven bristles of which the longest is apical and the rest along the ventral margin, and with as many (somewhat robust) hairs. Subtriangular brown labrum has basal width about 0.75× that of length and up to 0.66× width of third antennal segment. Enlarged labella each with a broad brown band above and an extensive dense field of small spinules below. Thorax brown to almost black on top. Three bristles on notopleuron. Abdominal tergites brown, with hairs well-developed especially at lateral and hind margins. Venter grey, but with more yellowish intersegmental bands, and with transverse rows of hairs below segments 3–6. Hypopygium brown, but apical thirds of cerci and proctiger pale yellow, and as figure 19B. Right side of hypandrium without a process. Legs with essentially brown femora and also tarsal segment 5 of front leg, the rest being variably more yellowish. Front leg with all five tarsal segments with a posterodorsal hair palisade and basitarsus about 7× as long as wide. Mid tibia with near-dorsal hair palisade extending about 0.8× length. Hairs below basal half of hind femur a little shorter and weaker than those of anteroventral row of outer half. Base of this femur as figure 19A. Hind tibia with 11–12 differentiated posterodorsal hairs, those in the basal quarter being somewhat fine, and one or two near mid-point and the pre-apical being more spine-like. Wings 1.7–2.3 mm long. Costal index 0.53–0.54. Costal ratios 2.62–2.95:2.58–2.95:1. Costal cilia 0.17–0.19 mm long. Three bristles on axillary ridge and strong hair at base of vein 3. Sc fades away before reaching R. Veins brown, but costa paler, and membrane 1

grey tinged (plainly evident to naked eye).