Megaselia hauclaudia, DISNEY, 2003

DISNEY, R. H. L., 2003, Tasmanian Phoridae (Diptera) and some additional Australasian species, Journal of Natural History 37 (5), pp. 505-639 : 555-557

Megaselia hauclaudia sp. nov.

(figure 23)

Material

H  : male, Tasmania, Mount Field National Park, Russell Falls , 11 January 1992 ( R. H. L. Disney —25-9) ( TMH).

P    : male, Tasmania, Hobart, Battery Point, De Witt Street, garden, 1–11 January 1992 ( RHLD —25-6) ( UMZC); 1 male, 1 female , Fern Tree, Grays Road , 147°15∞E, 42°57∞S (grid ref. 203474), 540 m altitude, 5–9 August 2000 ( RHLD —25-41-43) ( UMZC) .

Etymology Named after its resemblance to M. claudia ; ‘hau’ meaning ‘not’.

Diagnosis

The combination of scutellum with anterior pair of minute hairs and posterior pair of bristles; mesopleuron bare; costal index>0.43 but <0.50; forked vein 3; hind tibia without differentiated anterodorsal hairs; frons with dense fine microsetae; hairing of abdominal tergites normal; front tarsi normal; haltere knob yellow; take this species to couplets 52 or 57 on p. 89 of Borgmeier’s (1967b) keys. It is distinguished from M. curticauda Borgmeier by the anal tube being longer (it being distinctly shorter than the midline length of the epandrium in Borgmeier’s species), the darker brown tip to the otherwise pale yellowish brown hind femur, and the more yellowish brown wing veins. The antials not being vertically below the anterolateral bristles distinguishes M. hauclaudia from M. pallidivena Borgmeier. Largely yellow legs, a longer anal tube and a large left hypandrial lobe will distinguish it from M. scabra Schmitz. At couplet 57 there is an error. Costal section 1 is shorter than 2+ 3 in M. claudia , as correctly stated in the text. The new species differs from M. luteiclava Borgmeier in having the hairs below the basal half of the hind femur clearly longer than those of the anteroventral row of the outer half and these hairs are normally spaced. By contrast those of M. luteiclava are ‘short and decumbent, closely set’. Other species running to these same couplets include the male of M. intricata Borgmeier , which was omitted from the keys in error (the female is keyed out on p. 85). It has a much shorter anal tube than the new species. Males of other, subsequently described, species running to the same couplets on p. 89 differ in having a clearly shorter anal tube, or in having enlarged abdominal spiracles, or stronger anterior scutellars and/or the abdominal tergites partly yellow. Females of these subsequently described species either have extensive yellow areas on the abdominal tergites or the hind femora are mainly a darker brown. The new species clearly resembles M. claudia , but the latter has two large SPS vesicles in the third antennal segment, whereas the new species lacks such vesicles. Furthermore, it differs from M. claudia in possessing a basal collar to the anal tube.

Male

Frons brown and wider than long. Lower supra-antennal bristles clearly shorter and less robust than upper pair, which are level with anterolateral bristles. The latter a little higher on frons than antials, which are a little closer to ALs than to upper SAs. Pre-ocellars a little closer together than either is from a mediolateral, which is slightly higher on frons. Four bristles on cheek and two longer ones on jowl. Third antennal segment pale brown, with darker arista. Palps yellow very lightly tinged brown, with seven bristles of which the most apical is longest. The orange-brown labrum with maximum width about three-quarters that of third antennal segment. Pale dusky yellow labella with very few spinules below. Thorax brown, but nearer orange than black. Notopleuron with three bristles. Abdominal venter brownish grey with hairs below segments 3–6. Hypopygium brown, with paler anal tube, and as figure 23A. Fore-tarsus slender, with posterodorsal hair palisades on segments 1–4 only, and segment 5 slightly shorter than 4. Near-dorsal hair palisade off mid tibia extends almost three-quarters of length. Hind tibia with 14–16 posterodorsals, of which 7–11 are distinctly longer and more robust, especially the lowest of these. Wing length 1.7–2.1 mm. Costal index 0.44–0.50. Costal ratios 2.95–3.95:1.69–2.15:1. Costal cilia 0.08–0.11 mm long. Axillary ridge with two bristles, which are longer than costal cilia. A small hair at base of vein 3. Veins brown and membrane tinged greyish brown.

Female

Head similar to male, except width of labrum is subequal or slightly greater than that of third antennal segment. Thorax as male but a little paler. Abdomen with brown tergites with small hairs, which are a little longer at rear margins of T 5– T 7 (figure 23C) and posterolaterally on T 2. Sternite 7 a narrow strip with small hairs, but expanded at rear end and with longer hairs, and posterolateral lobes of sternum 8 as figure 23B. Cerci dusky pale yellow and at least twice as long as broad; with five longer hairs along posterior (inner) edge, of which the pre-apical is a little longer still, and with as many shorter ones distally. Internally with furca (S9) evident as a brown subcircular disc that is part folded upwards. With four rectal papillae. Dufour’s crop mechanism about twice as long as greatest breadth and gradually tapered to a rounded posterior end. Legs similar to male. Wing length 2.49 mm. Costal index 0.48. Costal ratios 4.69:2.81:1. Costal cilia 0.11 mm long. Axillary ridge with three bristles. Otherwise as male.