Michotamia coarctata (Macquart)

Scarbrough, A. G., 2010, An overview of the Afrotropical Ommatiinae (Diptera: Asilidae) with a key to genera, Zootaxa 2540, pp. 1-47 : 22-24

Michotamia coarctata (Macquart)

Figs. 4, 10, 52–55

Ommatius coarctatus Macquart, 1855: 80 (60). Kertész 1909: 307. Hull 1962: 435. Oldroyd 1960: 299.

Michotamia coarctata (Macquart) , Oldroyd 1980: 346.

Redescription, female. Reddish-brown or brown. Body 19.3 mm, wing 15.5 mm. Head: Face slightly produced beyond eye on lower 1/2, brownish-yellow tomentose; vestiture yellowish, setae abundant, short medially, slightly longer ventrally; 2–3 long thin setae on dorsal 1/2, several unusually stout bristles on lower 1/4 medially, sparse along oral margin laterally; FHWR 1.0:4.8. Palpus yellow setose, 1–3 apical setae brownish. Proboscis 3/4 as long as eye laterally, robust, black, apex round, not pointed apically; setae yellowish, sparse. Antenna ( Fig.4) mostly brownish or yellowish-brown; setae brown, short, especially thin dorsally, 2 below pedicel stout, as long as segment or slightly longer; pedicel and scape yellow, about 1/3 as long as flagellum combined; flagellum 3.8 times as long as stylus. Frons brownish-yellow tomentose, setae yellow, dense laterally, slightly longer than scape. Ocellar tubercle brown setose, 2 dark setae, about as long as scape. Occiput yellowish tomentose with yellowish setae dorsally, white ventrally tomentose with white setae ventrally; postocular bristles brown, stout dorsally, none strongly proclinate, only slightly curved anteriorly; thinner, yellow, postocular bristles laterally.

Thorax: Pronotum yellowish tomentose dorsally, gray laterally; bristles stout, yellow. Mesonotum low, not arched significantly dorsally; blackish with thin brown tomentum dorsally, yellowish-gray laterally, yellowish posteriorly; vestiture sparse, mostly thin, short setae brown or yellow, dorsocentrals seta-like, 5 stout black bristles laterally. Scutellum blackish, tomentum yellowish with sparse yellow setae, apical groove and bristles absent. Pleuron yellow tomentose, vestiture sparse, yellow, bristles on dorsal 1/2, including anepimeral bristle, stout. Halter yellow. Wing ( Fig. 52): Yellowish with dense yellow microtrichia, paler basally. Cell r 4 just beyond cell d, trumpet-shaped, much wider at wing margin than basally. Crossvein r-m beyond middle of cell d, longer than CuA 1 + M 3. Cell m 1 narrow basally, abruptly beyond, sides divergent to wing margin; m 1 1.0:2.3:2.5. Cell m 3 short, apex just beyond r-m well before base of m 1. Legs: Coxae black, yellow tomentose with thin yellow setae and stout bristles. Trochanters, femora, and tibiae reddish-yellow or yellow; bristles sparse, mostly black, stout, anterior bristles long, shorter ventrally; meso- and metathoracic femora without anteroventral bristles; MFWLR 1.0:4.3. Tarsi reddish-brown, basal tarsomere of prothoracic tarsus yellow; bristles black.

Abdomen: Largely yellowish with yellow tomentum; segments 5–6 blackish with yellow apically; clavate, segment 5 twice as wide in dorsal view as junction of segments 2–3, fusiform apically. Setae short, mostly brownish, yellow on tergites 1–4 laterally and sternites 1–4 entirely. Terminalia ( Figs. 53–55): Tergite 8 extending below covering sternite 8 basally. Sternite 8 longer than wide, apical and basal margins strongly emarginated medially, with inverted V-shape triangle externally and angular support apodeme internally. Genital furca simple, arms sclerotized, base membranous. Spermatheca with oval apical bulbus, a large asymmetrical valve, and tightly coiled duct.

Male. Unknown.

Type examined. MADAGASCAR: (holotype ♀, OXUM) .

Remarks. Michotamia coarctata is distinguished from congeners by the combination of the diagnostic characters of the genus and terminalia ( Figs. 53–55). The robust proboscis with rounded apex; unusually stout bristles on the lower face medially; absence of marginal scutellar bristles; reddish or yellow legs; femora without anteroventral bristles; an elongate strongly constricted abdomen, and the only species known from Madagascar further distinguish the species. Although the male of M. coarctata remains unknown, the dozen or so Oriental species known ( Scarbrough & Hill 2000; Joseph & Parui 1998, Oldroyd 1972), the aedeagus is usually long, curved or sigmoid, extending dorsally between or above the epandria, and is tightly bound by the genital sheath, i.e. epiphallus absent ( Figs. 56–57).

The holotype of M. coarctata is in fair condition. However, the right flagellum and stylus and left leg are absent; the right leg is glued to the specimen pin; wings are covered with dust and some fungi although the surface characters are readily distinguished; head setae are covered by fungi and terminalia are in a microvial. Data labels: [Circle, narrow red border] ‘Holo- / type’; [white rectangle] ♀ Allocotosia / coarctatus Macq. / 1723 in Coll. Bigot; [small white rectangular glued to larger label] ♀ coarctatus Macq. n. sp. [in script], Madagascar [below large label, at end]; Type: 350 / Ommatius coarctatus Macquart / Hope Dept. Oxford.