Microgephyra chrysothorax, Hauser & Irwin, 2005

Hauser, Martin & Irwin, Michael E., 2005, The subfamily Xestomyzinae (Diptera: Therevidae) new to Madagascar, with the description of four new species, African Invertebrates 46, pp. 181-202 : 185-186

Microgephyra chrysothorax sp. n.

Figs 1A, 1B , 2A, 2B , 3A, 3B , 4A, 4B , 5A, 5B , 6A , 7A , 8A

Etymology: Gr. chrysos (gold); Gr. thorax (chest). Under magnification the red thorax has a golden reflection.

Diagnosis: This species is the only Xestomyzinae found in Madagascar with holoptic eyes in males ( Fig. 1A ). It can be distinguished from the other species by the presence of golden microsetae on the thorax. In M. chrysothorax the antenna is shorter than the head ( Figs 2A, 2B ), and points downward ( Figs 2A, 2B ); the scape is subequal to flagellum; the wing is spotted ( Fig. 7A ).

Description:

Male.

Head: Ocellar tubercle elevated, dark brown with weak golden pubescence, without setae. Eyes holoptic, reddish brown, ommatidia larger in upper half ( Fig. 1A ). Frons ground colour black to brown with white pubescence in upper part of frontal triangle; without setae. Parafacial white pubescent along eye margin, only lateral to antennal insertion polished brown, without setae. Genal setae sparse, brownish. Lower face densely white pubescent; comma-shaped area along tentorial pit polished black.Antenna shorter than head length, light brown with faint white pubescence. Scape 3 times longer than wide with short, brown setae. Pedicel nearly square with a few brown setae. First flagellomere oval, covered with white microsetae. Second and third flagellomeres small, square with apical stylus on third flagellomere ( Fig. 2A ). Maxillary palp elongate, one segmented, constricted in the apical third, pale yellow brown with white pubescence and short brown setae. Proboscis as long as head.

Thorax: Mesonotal and pleural cuticle orange-brown. Mesonotum silver-golden pubescent with sparse, short, black setae. Scutellum black pubescent. Pleural cuticle pale brown. Anepimeron and ventral part of anepisternum polished. Katepisternum, dorsal part of anepisternum and meron white pubescent. Pleuron without setae, only katatergum with a few long yellow setae and one long black seta. Wing membrane translucent yellowish-grey, completely covered with microtrichia; with irregularly brown pattern, especially around the cross veins m-cu and r-m as well as a brown band apical to the cell d and the apical tip of the wing ( Fig. 7A ). Pterostigma yellowish. Halter pale yellowish-brown. Coxae yellow, lightly silver pubescent. Fore coxa with 2, mid coxa with 2, hind coxa with 4 black macrosetae; hind coxa with dorso-lateral macroseta. Legs pale-brown, base of hind femur paler, covered with short black setae.

Abdomen: Cuticle dark brown dorsally, pale brown-yellowish on sternites and laterally on tergites, polished, with sparse, short, black setae. Gonocoxite with two to three black macrosetae, next to several smaller ones ( Figs 3A , 4A ). Inner margin of gonocoxite straight. Epandrium with apical corners only a bit folded; subepandrial sclerites with black setae on apical half ( Fig. 4B ). Gonostylus small, pear-shaped, pointed ( Figs 3A, 3B , 4A ). Hypandrium with a few brown-yellowish setae. Aedeagus with oval shaped apical cap ( Figs 5A, 5B ; ac). Ejaculatory apodeme in ventral view apically broadened ( Fig. 5A ; ea).

Body length: 4.5 mm. Wing length: 3.7 mm.

Female similar to male except as follows:

Head: Frons slightly wider than ocellar tubercle, divergent ventrally. Upper frons white to dark brown pubescent, lower frons above antenna lacking pubescence, shagreened. Eye margin with triangular white pubescent spot dorso-lateral to antenna insertion ( Fig. 1B ). Legs dark brown, except tip and base of femora.

Thorax: Wing membrane generally more infuscate and darker than in males.

Abdomen: Cuticle dark brown with black, erect setae, longer than in male. Sternite 8 yellowish with a row of 11–14 long, black macrosetae, each flattened at its apex and a second ventral row of 4–6 shorter, black, pointed macrosetae. Furca as in Fig. 6A .

Body length: 5.5–6.9 mm. Wing length: 4.2–4.8 mm.

Holotype ( CASC type number: 18066): MADAGASCAR: Toliara Province: Andohaela Nat’l Park, Tsimela, Parcelle II, [24.937, 46.627], 175 m, 1–11.x.2003, MTr, MI, FDP, RHH, 1 ơ (166260, CASC).

Paratypes: MADAGASCAR: Toliara Province: Andohaela Nat’l Park, Tsimela, Parcelle II, [24.937, 46.627], 175 m , 10–21.ix.2003, MTr, MI, FDP, RHH, 1^ (166240, MEI) ; 1–11.x.2003, MTr, MI, FDP, RHH, 1ơ (166269, ZMUC) , 1ơ (166272, NMSA); 11–21.xii.2003, MTr, MI, FDP, RHH, 1^ (166259, MEI) ; 28.i– 12.ii.2004, MTr, MI, FDP, RHH, 1ơ (166278, SMNS) ; Beza Mahafaly Reserve , [23.689, 44.596], 200 m, in spiny forest, Parcel II , 10–21.xi.2001, MTr, RHH, MI, 1^ (146518, MEI) ; 9–16.i.2002, MTr, RHH, MI, 1^ (148827, INHS) ; Beza Mahafaly Reserve , [23.657, 44.629], 165 m, in dry gallery forest, Parcel I , 21– 28.xi.2001, MTr, RHH, MI, 1^ (146512, MEI) ; 28.xi–4.xii.2001, MTr, RHH, MI, 1^ (148825, BMNH) ; 2–9.i.2002, MTr, RHH, MI, 1^ (138466, MNHN) ; Beza Mahafaly Reserve, near Bellevue , [23.687, 44.591], 200 m, in spiny forest , 2–9.i.2002, MTr, RHH, MI, 1^ (148826, CASC) ; Cap Ste Marie Special Reserve , 7 km S ANGAP office, [25.588, 45.163], 40 m, vegetated dunes nr coast , 9–15.xii.2002, MTr, RHH, MI, 1ơ (146484, MEI) .

Biology: This species was collected from September to February in Malaise traps in dry forest, gallery forest, deciduous forest, and spiny forest, as well as on coastal dunes with vegetation.

Figures

Fig. 1 A–H. Heads frontal; left column males, right column females: (A, B) Microgephyra chrysothorax sp. n.; (C, D) Microgephyra falx sp. n.; (E, F) Microgephyra elegans sp. n.; (G, H) Microgephyra madagascariensis sp. n. Scale bar = 1 mm.

Fig. 2 A–H. Heads lateral; left column males, right column females: (A, B) Microgephyra chrysothorax sp. n.; (C, D) Microgephyra falx sp. n.; (E, F) Microgephyra elegans sp. n.; (G, H) Microgephyra madagascariensis sp. n. Scale bar = 1 mm.

Fig. 3 A–H. Gonocoxites; left column ventral, right column dorsal: (A, B) Microgephyra chrysothorax sp. n.; (C, D) Microgephyra falx sp. n.; (E, F) Microgephyra elegans sp. n.; (G, H) Microgephyra madagascariensis sp. n. Abbreviations: gc – gonocoxite, gr – gonocoxal ring, gs – gonostylus, h – hypandrium, spa – spiculose area. Scale bar = 0.5 mm.

Fig. 4 A–H. Male terminalia; left column gonocoxites (lateral), right column epandria (ventral): (A, B) Microgephyra chrysothorax sp. n.; (C, D) Microgephyra falx sp. n.; (E, F) Microgephyra elegans sp. n.; (G, H) Microgephyra madagascariensis sp. n. Scale bar = 0.5 mm.

Fig. 5 A–H. Aedeagi; left column ventral, right column lateral: (A, B) Microgephyra chrysothorax sp. n.; (C, D) Microgephyra falx sp. n.; (E, F) Microgephyra elegans sp. n.; (G, H) Microgephyra madagascariensis sp. n. Abbreviations: ac – apical cap, da – dorsal apodeme, ea – ejaculatory apodeme, lds – lateral distiphallus sclerite, va – ventral apodeme. Scale bar = 0.5 mm.

Fig. 6 A–D. Furcae, dorsal view: (A) Microgephyra chrysothorax sp. n.; (B) Microgephyra falx sp. n.; (C) Microgephyra elegans sp. n.; (D) Microgephyra madagascariensis sp. n. Abbreviations: ag – accessory gland, f – furca, sr – sclerotized ring, ss – spermathecal sac, ssd – spermathecal sac duct, st – spermatheca, std – spermathecal duct, S10 – sternite 10. Scale bar = 0.5 mm.

Fig. 7 A–D. Right wings: (A) Microgephyra chrysothorax sp. n.; (B) Microgephyra falx sp. n.; (C) Microgephyra elegans sp. n.; (D) Microgephyra madagascariensis sp. n.

Fig. 8 A–D. Distribution maps: (A) Microgephyra chrysothorax sp. n.; (B) Microgephyra falx sp. n.; (C) Microgephyra elegans sp. n.; (D) Microgephyra madagascariensis sp. n.