Afroestricus minutus (Bromley)

Scarbrough Table Of Contents, Aubrey G., 2005, Afroestricus, a new Afrotropical Ommatine (Diptera: Asilidae) genus with twenty species and two species groups, Zootaxa 1041 (1), pp. 1-76 : 35-39

Afroestricus minutus (Bromley)

Figs. 81–90 , 194

Ommatius minutus Bromley, 1936: 129 comb. n. Hull 1962: 436; Oldroyd 1980: 347.

Redescription, male. Brown with mostly gray tomentum and white to pale yellow vestiture. Body 6.3–7.7 mm; wing 4.9–6.3 mm. Head: Face ventrally, yellowish­gray tomentose with pale yellow or white vestiture, six to seven long brown bristles and sparse brown setae present dorsally; FWLR 1.0:4.5–1.0:5.4. Antenna with basal two segments yellow to light brownish­yellow and black setae; flagellum brown, as long as scape; longest ventral seta as long as flagellum or scape; FWLR 1.0:1.1–1.0:1.7. Frons brownishyellow tomentose; setae slightly longer than scape. Occiput brown tomentose behind ocellar tubercle, yellowish­gray to gray tomentose, ocellar tubercle brown posteriorly; setae white to pale yellow, sparse black setae often present; six to nine black postocular bristles present, longest bristle proclinate, tip about 1/2 distance to ocellar tubercle.

Thorax: Pronotum gray tomentose with black or yellow bristles. Mesonotum mostly yellowish­brown tomentose, two narrow median stripes and two lateral dark spots present, tomentum yellowish­gray to gray laterally and posteriorly; vestiture dark brown or black, pale yellow setae between rows of dorsocentral bristles posteriorly and laterally above wing bases; longest anterior acrostichal setae quite thin, as long as to slightly longer than scape; four or five lateral and six or seven dorsocentral bristles, long and thick, the latter wide spaced, extends forward as a row to postpronotum posteriorly. Scutellum yellow to yellowish­gray tomentose with sparse fine, short yellow setae, two black marginal bristles, and a prominent preapical groove. Pleuron mostly gray tomentose, anepisternite yellow with sparse setae, and one anepimeral and four katatergal long, stout, black bristles. Halter yellow.

Wing ( Fig. 3b ): Entirely yellow to brownish­yellow microtrichose. Cell r 1 slightly rounded apically; vein R 2+3 weakly curved forward. Cell r 4 with base just beyond apex of cell d; vein R 4 only slightly curved anteriorly apically. Crossvein r­m before middle of cell d. Base of cell m 1 cell narrow, wide just beyond base with sides gradually divergent toward wing margin; m 1 WR 1.0:3.6:4.0–1.0:4.0:5.2.

Leg: Coxae brown, gray tomentose with abundant long, white setae. Trochanter, femora and tibiae yellow. Fore femur with ventral row of white setae, two to three unusually long. Middle femur without preapical posteroventral bristle. Hind femur with most or all anterior and anteroventral bristles black, one to two bristles sometimes yellow; HFWLR 1.0:4.9–1.0:5.3. Tibiae with mostly black bristles; fore tibia with two to three yellow lateral bristles; hind tibia with two long black apical bristles. Tarsi mostly yellow with black bristles; apical tarsomere sooty brown; fore tarsus with three, and middle tarsus sometimes with one yellow bristle laterally.

Abdomen: Mostly dark brown, apical margins of segments slightly lighter and apical segments usually brownish­yellow to yellow; tomentum mostly gray with white setae, yellow brown dorsally on most terga with black setae.

Terminalia ( Figs. 81–86 ): Brownish­yellow to yellow. Epandrium wide apically, notched dorsoapically; a broad, W­shaped emargination present; median margin of emargination produced, rectangular in lateral view; ventral corner of emargination hooked. Gonostylus distinctive. Distiphallus horizontal, apex narrow, exposed laterally; epiphallus flat, wide apically. Gonocoxite short, truncate anteriorly. Hypandrium triangular apically.

Female. Differs as follows. Body 6.6–7.0 mm; wing 5.1–5.4 mm. FHWR 1.0:4.2– 1.0:4.8; FWLR 1.0:1.5–1.0:1.7; m 1 WR 1.0:3.6:3.8–1.0:3.8:3.9; HFWLR 1.0:5.6–1.0:5.8. Head: Face with numerous black bristles and several black setae dorsally. Postocular bristles strongly proclinate with apex of longest bristles above ocellar tubercle. Wing: Crossvein r­m about 2/3 as long as CuA 1 +M 3. Leg: Fore femur with a weak, short, anterior preapical bristle. Fore and middle femora with two to three long, black, ventral setae. Hind femur with two to three unusually thin bristles on basal 1/2 posteriorly, usually yellow, sometimes one bristle black. Fore tibia with only black bristles laterally. Fore tarsus with only one yellow bristle. Abdomen: Apical terga with bristly setae and bristles, those in apical corner of tergum 8 thickest and longest. Terminalia ( Figs. 87–90 ): Tergum 9 narrow medially, strapelike. Sterna 7–8 mostly black setose. Sternum 8 triangular, anterolateral margins membranous. Spermatheca short, horizontal, carrot­shaped, weakly annulate. Genital fork distinctive.

Types examined. SOUTH AFRICA: 1 M [holotype Ommatius minutus Bromley ], Pretoria [25°43’S 28°16’E], 17.i.1915, H.K. Munro (NMSA); 1 F [allotype O. minutus Bromley ], Pretoria [25°43’S 28°16’E], 31.xii.1913 (NMSA); 1 F, Pretoria [25°43’S 28 °16’E], 25.xii.11, H.K. Munro ~ Paratype, Ommatius minutus Br (USNM) ; 1 F, Pretoria [25°43’S 28°16’E], 28.xii.16, H.K. Munro ~ Paratype, Ommatius minutus Br (USNM) .

Additional material. BOTSWANA: 1 M, Tsessebe, Bechuanaland, leg. Zumpt, i.56 ( BMNH) . MALAWI: 1 F, Nyasaland, Shire River , Blantyre Ncheu road, 27.xi.58 550 m, E.S. Ross and R. E. Leach ( CASC) . MALI: 2 F, Coll. Mus. Tervuren, Mali: R.C. T.­ MPesoba, 8.ix.1970, G. Pierrand ( MRAC) . NAMIBIA, 1 M, SW Africa (W39), Kombat , 16–17.ii.1972 ( BMNH) . SOUTH AFRICA: 1 M, Transvaal, Kruger Park, 9.xii.1972, Shongile Borehole nr. Letaba [23°55’25”S 30°07’33”E], tree trunks and water edge, Stuckenberg Family 2331 Cd ( NMSA) ; 1 M, 3 F, South Africa: Transvaal, [25°0’S 31°7’E], 6.i.1970, Mazithi dam grassland, 10 km north of Tshokwane , B and P. Stuckenberg 2431 Db ( NMSA) ; 1 F, South Africa: Transvaal, 2331 Dc , Letaba [23°55’25”S 30°07’33”E] Camp xii.1972, on tree trunks, Stuckenberg Family ( NMSA) ; 2 M, South Africa: Transvaal, 9.xii.1972, Shongile Borehole nr. Letaba [23°55’25”S 30°07’33”E], tree trunks and waters edge, Stuckenberg Family 2331 Cd ( NMSA) ; 1 F, South Africa: Transvaal, Kruger Park [25°0’S 31°7’E], 9.xii.1972 Mazithi dam grassland, 10 km north of Tshokwane, B and P. Stuckenberg 2431 Db ( NMSA) ; 1 F, South Africa: Natal, Goedhoek nr. Babanago , 28°23’5S: 30°05’E, 24.iii.1990, P.E. Reavell ( NMSA) ; 2 M, 2 F, Sth [South] Africa: Cape Prov , 35 km W. Kimberley [28°40’S 24°50’E], 2824 CB 17.iii.1982, J. Londt and L. Schoeman, Acacia­grass­sand ( NMSA) ; 4 M, 5 F, South Africa: Transvaal, Kruger Park [25°0’S 31°7’E], 9.i.1974, Bangu Borehole grass, mud, 10 km SE Balule 2431 Bb, B. and P. Stuchenberg ( NMSA) ; 1 F, S. Africa: Transvaal, 37 km N. Louise Trichardt Limpopo Val. [26°32’N 29°16’E], 2229DD, i.1975 Struckenberg, arid Bushveld ( NMSA) ; 2 F, South Africa: Transvaal, Kruger Park [25°0’S 31°7’E], 10 km SE Potgietersrus [24°09’S 29°04’E] on Rd to Zedediela 24–27.i.1978 JGH Londt, bushveld ( NMSA) ; 1 F, South Africa: Transvaal, Kruger Park [25°0’S 31°7’E], 37 km N. Louise Trichardt Limpopo Val. [26°32’N 29°16’E], 22290D, i.1975, Stuckenberg, arid bushveld ( NMSA) ; 1 F, South Africa: Natal, 25 km E. Louwsburg , 20.ii.1979, JGH Londt grassy area, near river ( NMSA) ; 1 F, Pretoria [25°43’S 28°16’E], 12.ii.71, J. M. de W. ( NMSA) ; 2 F, S. Africa: Transvaal , 10 km SE Potgietersrus [24°09’S 29°04’E] on rd to Zebediela 24.i.1978, J.G.H. Londt Bushveld ( NMSA) ; 1 F, South Africa: Natal, 25 km E. Louwsburg , 20.ii.1979 grassy, area near river E. ( NMSA) ; 1 F, Pretoria [25°43’S 28°16’E], 10.i.1932, G. Van Son ( NMSA) ; 1 F, Pretoria [25°43’S 28°16’E], 12.ii.71, J. Mdeh. ( NMSA) ; 1 F, South Africa: 2229 CA, Transvaal, Alldays [22°39’51”S 29°11’43”E], 25.vi.78 JGH Londt, bushveld ( NMSA) ; 1 M, 10 F, South Africa: 2427BA, Bulge River 25–30.i.1978, JGH Londt open, grassveld area ( NMSA) ; 2 M, South Africa: Bosbokrand , 15.xii.1980, F. Horniball ( NMSA) ; 1 M, South Africa: Dundee [28°14’S 30°16’E], 18.xii.78, J.G. Theron ( NMSA) ; 1 M, South Africa: 2427BA, Transv. [Transvaal], Bulge River , 30.i.1978 JGH Londt, open grassveld area ( NMSA) ; 1 F, South Africa: 2229 CC, Transvaal, Blouberge , 10 km NW Vivo, 25.i.78, J. G. H. Londt, mountain base, grass, bushveld ( NMSA) ; 4 F, South Africa: Transvaal , 8 km NW Barberton [25°48’S 31°04’E], on Bagolass Rd SE253000, 6–8.vi.1985 J. Londt, bushveld long grass ( NMSA) ; 1 F, Pretoria [25°43’S 28°16’E], 10.i.1932, G. Vanson Transvaal Museum ( NMSA) ; 1 F, South Africa: Transvaal, 9.xii.1972, Shongile Borehole nr. Letaba [23°55’25”S 30°07’33”E], tree trunks and water edge, Stuckenberg Family 233 Kd ( NMSA) ; 1 M, 3 F, South Afica: Transvaal [25°0’S 31°7’E], 6.i.1974, Mazithi Dam grassland, 10 km North of Tshokwane, B and P Stuchenberg 24310b ( NMSA) ; 1 F, South Africa: Transvaal, Letaba [23°55’25”S 30°07’33”E], Camp, xii.1972, on tree trunks, Stuckenberg Family ( NMSA) ; 1 M, South Africa: Natal, Goudhoek nr. Babanango , 28°23’S 31°05’E, 24.ii.1990, P.E. Reavell ( NMSA) ; 2 M, 7 F, South Africa: 2427BA, Transv. [Transvaal], Bulge River , 30.i.1978 JGH Londt, open grassveld area ( NMSA) ; 2 M, Bosbokrand , 15.xii.1910, F. Honiball ( NMSA) ; 1 F, Dunden 18.xii.78, J. G. Theron ( NMSA) ; 2 F, 2229 CA Transvaal, Alldays [22°39’51”S 29°11’43”E], 25–26.i.78 JGH Londt, bushveld ( NMSA) ; 1 F, 2229 CC Transvaal, Blouberge, 10 km NW Vivo, 25.i.78, JGH Londt, Mountain Basegrass , bushveld ( NMSA) . ZIMBABWE: 2 F, Nyamandhlorn, S. Rhodesia , 6.ii.1972, Nat. Museum S. Rhodesia, Leg. E. Pinhey ( NMZB) .

Distribution ( Tables 1, 2; Fig. 194 ). Widespread ( Botswana, Malawi, Mali, Namibia, South Africa, Zimbabwe); collected between November and June, in open grassveld, bushveld, and trees along shores bordering rivers. Data label show the species rests on tree trunks, grass, sand, or mud shore lines.

Remarks. Afroestricus minutus is distinguished from congeners by its small size and distinctive terminalia ( Figs. 81–90 ). It is similar to A. sadaukii but differs in the shorter, wider flagella, yellow to brownish­yellow scape and pedicel, yellow trochanters, the short anterior acrostichal setae, and yellow ventral bristles of the middle and hind femora. Additionally, the spermathecae are short, not recurved, carrotshaped, surface slightly annulated, and the spermathecal duct is attached at the end rather than prebasally.

Figures

FIGURE 194. Distribution of six species of Afroestricus in Africa and Madagascar.

FIGURES 81–90. Afroestricus minutus (Bromley). Male terminalia: 81–83. Lateral, dorsal, and ventral views. 84. Gonostylus. 85–86. Aedeagus, dorsal and lateral views. Female terminalia: 87–88. Dorsal and ventral views. 89. Spermatheca. 90. Genital fork.

FIGURES 3–4. Character states of the wing and postocular bristles of the subgenus Afroestricus Scarbrough. 3a–b. Wing venation of the macroscelis and the minutus species groups. 4a–b. Short, erect and long, thin, postocular bristles bristles. Abbrevations: First radial cell=r1; fourth radial cell=r4; discal cell=d; radial­medial crossvein=r­m; first medial cell=m1; third medial cell=m3.