Megaselia species B

DISNEY, R. H. L., 2003, Tasmanian Phoridae (Diptera) and some additional Australasian species, Journal of Natural History 37 (5), pp. 505-639 : 595-596

Megaselia species B

(figure 47A, B)

This species appears to be only known in the female sex and is probably an undescribed species.

Material

Female, Tasmania, Hobart, Battery Point, De Witt Street, garden, 1–11 January 1992 (Disney—25-38) ( UMZC) .

Diagnosis

The combination of scutellum with anterior pair of short fine hairs and posterior pair of bristles; eleven hairs (subequal to those scutum) on mesopleuron; costal index 0.47; no differentiated anterodorsal hairs on hind tibia; brown halteres; very sparse and fine microsetae on frons; and brown palps; will take this species to couplet 14 on p. 206 of Borgmeier’s (1967a) keys, to M. politiceps Borgmeier. It is immediately distinguished from the female of the latter by its swollen front basitarsus with several rows of hairs reduced to small spinules and by its antials being clearly closer to upper SAs than to anterolateral bristles. Posterolateral lobes of abdominal sternum 8 only projecting a little rearwards; brown femora; hairs below basal half of hind femur not differentiated from adjacent hairs of anterior face; and abdominal tergite 6 with almost straight hind margin.

Female

Frons brown, clearly wider than long, and with 68–76 hairs. Upper SA bristles longer than lower pair (in the only available specimen the right lower SA is broken off, but its stump is weaker than upper SA. On the left side there are two lower SAs, which are about 0.7× as long as upper pair). Antial bristles slightly higher on frons than upper SAs and ALs distinctly higher than antials. Pre-ocellars a little further apart than either is from a mediolateral bristle, and all four bristles in an irregular transverse row. Three bristles on cheek and two stronger ones on jowl. Third antennal segment brown and lacking SPS vesicles. Palps paler brown, with a darker short basal segment; with three short, one medium, one short bristles and about six hairs, and outer face with irregular pits. Pale yellowish brown labrum subtriangular and at most only 0.8× as wide as third antennal segment. Pale whitish yellow labella each with pale brown band above and very few small spinules below. Thorax brown with three bristles on notopleuron. Abdominal tergites brown with only small hairs, which are a little longer at rear of T6. T1–T5 clearly wider than long and only gradually narrowing from T2 to T5. T5 and T6 as figure 47A. Venter brownish grey with slightly paler intersegmental bands. With few hairs below segments 3–6, there being only one or two on both 3 and 4. Posterolateral lobes of sternum 8 with three submarginal hairs and several shorter ones in front of these, and with short pubescence. Brown cerci short and with one long hair and several shorter ones. Internal features obscured by numerous developing eggs. Front basitarsus as figure 47B. Only segments 1–4 with posterodorsal hair palisade. Segment 5 clearly longer than 4. Mid tibia with near-dorsal hair palisade extending just past mid point. About a dozen differentiated posterodorsal hairs on hind tibia, but only half dozen in middle are at all robust. Wing 1.2 mm long. Costal ratios 2.2:1.4:1. Costal cilia 0.08–0.09 mm long. Sc obscure and fading away well before R. Minute 1

hair at base of vein 3. Two axillary bristles, the longer outer one being subequal to costal cilia. Veins brown, but thin veins fading away towards wing margin and 7 obscure. Membrane only very lightly tinged grey.