Ommatius (Pygommatius) grossus, Scarbrough & Marascia, 2003

Scarbrough, Aubrey G. & Marascia, Claudio G., 2003, Revision of Ommatius Wiedemann (Diptera: Asilidae). IV. Pygommatius subgen. nov. with twenty-five Afrotropical species, Zootaxa 228 (1), pp. 1-94 : 35-37

Ommatius (Pygommatius) grossus , sp. n.

Figs. 10 , 24 , 134­138

Male. Black. Length, body 12.8­13.3 mm; wing 9.7­10.0 mm. Head: Face wide, produced anteriorly, gently rounded from base of antenna to epistomal margin; yellow tomentose with abundant long setae, yellow or black; 8­9 thin, black bristles present, pencil­like bristles yellow or black; 1.0:4.6­1.0:4.7. Antenna black setose, 3­4 bristly setae project to apex of flagellum. Frons yellowish­brown to brown tomentose, setae mostly yellow, sparse black setae present. Ocellar tubercle with 5­6 long, black, bristly setae, all about same length, 2 posterior setae thickest. Occiput with several black postocular bristles, longest with apex one­third to half distance toward ocellar tubercle.

Thorax: Mesonotum dorsally mostly brown tomentose, margins yellow, with mostly black setae; 4 lateral and 3­4 dorsocentral bristles, most of latter thin, posterior bristle thickest, all black; long, mostly yellow setae between rows posteriorly. Scutellum gray tomentose with scattered yellow setae and 2 black marginal bristles, setae subequal to bristles. Pleuron gray tomentose with mostly scattered, yellow setae, anepisternum with sparse, black setae; katatergal bristles yellow or black. Halter yellow.

Wing ( Fig. 10 ): Largely dense microtrichose, sparse in basal cells behind veins. Cell r 4 with R 4 slightly convex at wing margin. Apex of cell m 3 slightly arched, perpendicular to wing axis, near r­m.

Leg: Coxae black, gray tomentose, white setose. Hind trochanter with 2 long, slender, yellow bristles, curved 90 o, slender with a slightly swollen apex. Femora and tibiae yellow setose, long posteriorly or laterally, somewhat shaggy with setae of irregular lengths and distribution. Fore and middle femora brown anteriorly and dorsally, brown­yellow to yellow ventrally, yellow extends posteroventrally; hind femur mostly yellow, apical fifth to fourth brown. Fore femur ( Fig. 24 ) ventrally with 3­4 thick, yellow bristles of uniform length basally. Middle femur 5­6 black bristles aligned anteriorly; basal half slightly concave and abundant yellow setae ventrally, bristles absent. Hind femur anteriorly with a row of several stout bristles, mixed long, thin and bristly yellow setae, longer anterobasal setae slightly wavy; abundant setae ventrally, anteroventral bristles absent; several posteroventral bristles present, yellow or black, those basally thickest; 1.0:5.4­1.0:5.5. Fore tibia with thin lateral fringe of long setae and thin bristles, most yellow, 1­3 basal bristles thick, black. Middle tibia laterally with several thin brown bristles. Hind tibia with narrow apex brown, and moderately long, yellow setae posteriorly. Tarsi with basal 2 tarsomeres yellow, narrow apex of second and remaining tarsomeres brown; fore and middle tarsi, sometimes hind tarsus, with yellow bristles.

Abdomen: Light brown to brown­yellow tomentose with mostly yellow setae; tergites 5­8 laterally with abundant setae, mostly yellow, short and aligned on margin of tergite 5, abundant longer and shaggy on 6­7, yellow and black or black on 8. Sternites 3­5 with flat, blade­like bristles, apices asymmetrically pointed; sternite 8 long, black setae apically.

Terminalia ( Figs. 134­138 ): Large, as long as segments 5­8. Ventral lamella basally with dense brassy setae projecting from a deep cavity. Epandrium with 3 long branches; median branch prominent, gradually narrowed to preapex, slightly wider beyond; dorsal and ventral branch shorter than median branch. Gonostylus bifid apically. Hypandrium apically with numerous flat bristles.

Female. Unknown.

SPECIMENS EXAMINED. Holotype ♂, DEMOCRATIC REPUBLIC OF CONGO: Coll. Mus. Congo / Urundi : t. Bururi 900 m / Nyamurembe 7­iii­1953 / P. Basilewsky ( MRAC). Paratype: 1 ♂, Belg. Congo / 8 mi SW of / Pweto 1080 m. / 15.i.1958 / E. S. Ross and / R. H. Leech ( CASC) .

Distribution. This forest species has been captured from 900 to 1080 meters at elevations from January to March in southeast Democratic Republic of Congo.

Etymology. Latin grossus , for large, referring to the large terminalia.

Remarks. In addition to the characters in the key, the long, shaggy setae of the legs, ventral concavity of the middle femur, fringe of yellow setae along the margin of tergites 5­6, and the large terminalia ( Figs. 134­138 ) characterize O. grossus .

Figures

FIGURES 1­10. Right wing of male Ommatius (Pygommatius) spp. 1. O. alatipes, sp. n..; 2. O. albatus Martin; 3. O. bingeri Oldroyd; 4. O. brevicornis Curran; 5. O. cingulatus Bromley; 6. O. comosus, sp. n..; 7. O. dasypogon Oldroyd; 8. O. digittatus Oldroyd; 9. O. fluvius sp. n..; 10. O. grossus, sp. n. Abbr. R4 =fourth radial vein, r4 = fourth radial cell, m1= first medial cell, m3=third medial cell, d = discal cell, r­m = radial­medial crossvein.

FIGURES 21­28. Right wing of male Ommatius (Pygommatius) spp. 21. O. talus, sp. n.; 22. O. vultus, sp. n.; 23­28. Right fore femur of male Ommatius (Pygommatius) spp. showing arrangement of anteroventral bristles. 23. O. brevicornis Curran; 24. O. grossus, sp. n.; 25. O. limbus, sp. n.; 26. O. litoreus, sp. n.; 27. O. strigiatus, sp. n..; 28. O. vultus, sp. n.

FIGURES 134­138. Male terminalia of Ommatius grossus, sp. n. 134­136. Lateral, dorsal and ventral views; 137. Gonostylus;138. Aedeagus, lateral view.