Megaselia multivesiculae, Disney, R. Henry L., 2006

Disney, R. Henry L., 2006, Eight new species of Megaselia Rondani (Diptera: Phoridae) from the United Arab Emirates, Oman, and Yemen, Zootaxa 1371, pp. 1-21 : 9-10

Megaselia multivesiculae sp. nov.

( Figs 12 – 13 )

In Beyer’s (1965) keys this species runs to couplet 10 on page 57, lead 2, to M. punctata Bridarolli. However this species has only two bristles on the notopleuron and a yellow haltere knob, as opposed to three bristles and a brown knob in the new species. Several subsequently described species run to the same couplet, but all have two bristles on the notopleuron. The female tergite 4 recalls a number of species but which differ in having only two bristles on the notopleuron and pale yellow haltere knobs ( Disney, 2006c).

Etymology

Named after the densely packed SPS vesicles of the male postpedicel.

Male

Frons brown, very similar to that of M. ebejeri ( Fig. 2 ), but with only 36 – 38 hairs, dense but fine microsetae and the lower SAs more robust but still shorter than upper SAs. Cheek with 5 – 6 bristles and jowl with two longer ones. Postpedicels subglobose, dark brown, with numerous, densely packed, SPS vesicles. Palps brown, with six bristles (the three most apical being the longest) and as many hairs. Labrum light brown and about 0.7x as wide as postpedicel. Labella pale but with light brown bands towards sides on top, and with only a few, widely scattered, short spinules below. Thorax brown. Mesopleuron bare. Three notopleural bristles and no cleft in front of these. Scutellum with an anterior pair of small hairs (subequal to those at rear of scutum) and a posterior pair of bristles. Abdominal tergites brown with the hairs at rear of T6 distinctly longer than rest. Venter light brown, and with a few hairs below segments 3 – 6. Hypopygium brown, including anal tube but with left lobe of hypandrium more straw yellow, and as Fig. 12 . Right lobe of hypandrium vestigial. With four rectal papillae. Legs with brown coxae to tibiae, but front tibiae more yellowish, and dusky straw yellow tarsal segments 1 – 4. Fore tarsus with posterodorsal hair palisade on segments 1 – 4 only, and that on 4 is less strongly developed. Dorsal hair palisade of mid tibia extends almost half of length. Hairs below basal half of hind femur subequal to those of anteroventral row of outer half. Hind tibia with a dozen weakly differentiated posterodorsal hairs. Spinules of apical combs simple. Wings 1.4 – 1.5 mm long. Costal index 0.42 – 0.43. Costal ratios 5.3: 1.5: 1. Costal cilia (of section 3) 0.08 – 0.09 mm long. Hair at base of vein 3 small. With three axillary bristles, all longer than costal cilia. Sc strong and ending in R1. Costa dusky straw yellow, rest of thick veins light brown and thin veins more grey. Membrane lightly tinged grey (just evident to naked eye when viewed against a white background). Haltere brown.

brown. T2 – T6 as Fig. 13 , the long bristles at rear of T4 being unusual. T7 with front margin 1.5 – 1.9x wider than posterior margin and the length about 1.3x breadth of front margin. With about 20 hairs, the five at the hind margin being a little longer than the rest. T8 light brown and about 1.1x broader at front margin than at rear margin and its length 1.1 – 1.2x its greatest breadth. Venter brown, and with a few hairs below segments 3 – 6. Sternite 7 an isoscles triangle whose length is almost 3x the breadth of the hind margin; and with about ten hairs, the four longest being at the hind margin. Posterolateral lobes at rear of sternum 8 short but broad and with almost straight hind margins; and each with three long hairs near rear margin and 2 – 5 shorter ones further forward. Cerci light brown and about 2.8x as long as broad. With four rectal papillae. Furca not evident. Dufour’s crop mechanism rounded behind and about 1.8x longer than its greatest breadth.. Legs similar to male. Wing similar to male except 1.6 – 1.8 mm long. Costal index 0.40 – 0.43. Costal ratios 3.8 – 5.7: 1.1 – 1.3: 1. Costal cilia 0.09 – 0.10 mm long. Sc ends just before reaching R1. Otherwise it and haltere as male.

The sexual dimorphism with regard to vein Sc is most unusual. Normally the vein fuses with R1 or else its tip falls short of the latter in both sexes.

Material

HOLOTYPE male, United Arab Emirates, Wadi Maidaq, water trap, 26.12.2005 – 2.i.2006, A. van Harten ( CUMZ, 32 – 150). Paratypes: 1 female, as holotype; 2 females, Wadi Safad, water traps, 26.12.2005 – 25.i.2006, A. van Harten ( CUMZ, 32 – 140).

Figures

FIGURES 12 – 13. Megaselia multivesiculae. (12) male, left face of hypopygium; (13) female, abdominal tergites 2 – 6. Scale bars = 0.1 mm.

FIGURES 1 – 4. Megaselia ebejeri. (1) female abdominal tergites 4 – 7; (2) male frons, with bristles represented by their basal sockets only; (3) female, lobes at rear of abdominal sternum 8; (4) left face of male hypopygium. Scale bars = 0.1 mm.