Ommatius (Pygommatius) dasypogon Oldroyd
Creators: name: Scarbrough, Aubrey G.
name: Marascia, Claudio G.
Publisher: name: Zenodo
Year: 2003
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Asilidae
Ommatius
Ommatius dasypogon

description: Ommatius (Pygommatius) dasypogon Oldroyd
Figs. 7, 32, 50, 110­117
Ommatius dasypogon Oldroyd, 1939, 2: 44.
Ommatius dasypogon: Hull, 1962: 436. Oldroyd, 1980: 347 (Afrotropical catalogue).
Redescription, male. Brown to black. Length, body 7.7­10.8 mm; wing 6.8­8.8 mm. Head: White tomentose, mostly white setose. Face with mystax dense white setose, setae of uniform length, apex of setal mass truncate, slightly drooping; 4­6 brown bristles present, pencil­like bristles absent; 1.0:3.3­1.0:4.1. Antenna mostly brown setose; style with or without ventral row of setae, sometimes apex with flat ‘tuft’ of short setae. Occiput with 3­ 5 brown postocular setae dorsally, 2 with apex near ocellar tubercle.
Thorax: Mesonotum subshiny, tomentum mostly brown­yellow, lightest posteriorly; 2 brown tomentose paramedial stripes and 2 lateral spots present; setae mostly brown, 4 lateral and 2 to 3 posterior dorsocentral bristles present, latter about as long as scutellar bristles. Scutellum pale brown­yellow tomentose, with numerous long, yellow or brown setae and 2 marginal bristles. Pleuron yellow to gray tomentose, yellow setose; anepimeral bristles absent. Halter yellow to red.
Wing (Fig. 7): Narrow apex and posterior dense microtrichose. Cell m 3 narrow, apex acute, near base of cell m 1.
Leg: Fore coxa usually yellow to yellowish­brown [dark in Ethiopian specimens], middle and hind coxae brown, all yellowish­gray tomentose with yellow setae. Femora yellow to slightly brown­yellow, apical half to three­fourths with a narrow brown anterodorsal stripe; fore femur with brown stripe often very faint; hind femur usually with a narrow dark brown stripe posteriorly, sometimes entirely yellow. Fore femur ventrally with a long row of moderately long, thin, yellow setae. Middle femur with 2 long anterior and 1 much shorter preapical posterodorsal bristle, all brown; several thin mostly yellow setae present in each ventral row with most slightly longer than width of femora. Hind femur (Fig. 32) anteriorly with a wide stripe of short yellow setae and 1 brown dorsoapical bristle; only 3­4 thin anteroventral setae present, all on basal half, one unusually long, about third as long as hind femur; 4 brown bristles present posteriorly, 2 on basal two­thirds and 1 pair on apical fourth; basally, 2­3 additional shorter setae present; HFWLR 1.0:8.0. Tibiae entirely or largely yellow with brown bristles, those on fore and middle tibiae unusually long and thin; hind tibia with an unusually long, thin, brown bristle anterobasally, about two­thirds as hind tibia. Tarsi with basal 2 tarsomeres yellow, apical 3 black, bristles black; fore tarsus with bristles unusually thick and long, spine­like. Apical 3 tarsomeres of hind tarsus (Fig. 50) with dense, short, white or yellow setae dorsally.
Abdomen: Subshiny dorsally, mostly light brown­yellow tomentose and pale yellow setose, tergites 5­8 dorsally sparse to abundant, brown setose; tergites 1­2 with long, thin setae, 3­6 with short setae, 7­8 with thicker, long setae. Sternites 3­5 with few to abundant, long, pale yellow bristles, apical third of sternite 3 with about 12 bristles, entire sternite 4 laterally with 18­20 bristles, and basal corners of sternite 5 with 2 bristles; remaining sternites with mostly very thin to bristly setae. Segments 7­8 dorsally very narrow, about half as wide as segment 3.
Terminalia (Figs. 110­114): Epandrium 3 branched, slender; dorsal and ventral branch short, latter capitate; median branch longer, capitate. Distiphallus very thin. Hypandrium with a cluster of fused setae medially, bases quite thick.
Female. Differs from male as follows: Body tomentum largely yellow, thorax and abdomen brown dorsally. Length, body 8.8­11.5 mm; wing 8.2­8.8 mm. Head: Face with mostly yellow vestiture, sparse; several brown bristles present; FHWR 1.0:3.9­1.0:4.5. Style normal, without flat, apical "brush" of short setae. Wing: Slightly yellow; vein M 1 arched subasally, but less so as in male. Leg: Fore coxa yellow. Fore femur with dorsal and anterior half brown, grading basally to yellow, otherwise yellow; hind femur largely brown with yellow base. Middle femur anteroventrally with several brown setae on basal half; longer yellow setae present posteroventrally. Hind femur with only 5­6 thin bristles anteroventrally and posteroventrally; long, erect, anterior setae absent; HFWLR 1.0:6.8­ 1.0:8.0. Fore and middle tibiae with anterior and narrow apex brown; hind tibia yellow posteriorly only. Basal 3 tarsomeres of fore and middle tarsi with abundant yellow setae dorsally; remaining tarsomeres and vestiture black. Abdomen: Brown­yellow tomentose with a large brown spot dorsally; sternites with only sparse, erect, yellow setae. Tergite 9 short, strap­like, about as wide medially as laterally. Terminalia (Figs. 115­117): Three spermathecae present; duct prebasal and lateral. Sternite 8 with apical margin produced medially, rectangular.
SPECIMENS EXAMINED. UGANDA: Holotype M (BMNH); 1 ♂, Lake Nabugabo / 17.iv.1972 / D. J. Greathead (BMNH). ETHIOPIA: 2 ♂, 5 ♀, ix.1911, R. J. Strody (BMNH); 1 ♀, C. Abyssinia, Maraquo, 2.v.1914, O. Kovacs (BMNH). KENYA: 1 ♂, 2 ♀, Marsabit, Nat. Res. 4200', 8.xii.1969, M. E. Erwin and E. S. Ross (CASC); 2 ♀, Marsabit Nat., Res. Lake Paradise, 4500', 10.xii.1969, M. E. Erwin and E. S. Ross (CASC). TANZANIA: 1 ♂, Kilimanjaro, Weru Weru, 10.iii.1963, D. J. Greathead (BMNH); 2 ♀, Lake Manyata Nat’l Park Mto, We Mbu 27.xi.1969, M. E. Erwin and / E. S. Ross (CASC).
Distribution. The species occurs at 1292 to 1385 meters in elevation in East­Central Africa. It was captured between April and September in the northern part of its range, and November through March in the southern portion of its range.
Remarks. The male of O. dasypogon is easily distinguished by the characters listed in the key and the abundant, unusually long, erect setae that borders the lower margin of the anterior brown stripe on the hind femur.
The holotype is in good condition.
description: Published as part of Scarbrough, Aubrey G. & Marascia, Claudio G., 2003, Revision of Ommatius Wiedemann (Diptera: Asilidae). IV. Pygommatius subgen. nov. with twenty-five Afrotropical species, pp. 1-94 in Zootaxa 228 (1) on pages 30-32, DOI: 10.11646/zootaxa.228.1.1, http://zenodo.org/record/5019043