Afroestricus chiastoneurus (Speiser)

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 : 16-20

Afroestricus chiastoneurus (Speiser)

Figs. 15–24 , 193

Ommatius chiastoneurus (Speiser), 1910: 105 comb. n. Hull 1962: 435; Oldroyd 1980: 347. Ommatius senex Bromley, 1936:127 syn. n. Hull 1962: 436; Oldroyd 1980: 347.

Redescription, male. Black. Body 11.4–15.0 mm; wing 7.1–9.3 mm. Head: Face yellowish to gray tomentose, 8 to 14 black bristles and scattered black setae present on dorsal 1/2; vestiture denser, longer, and yellowish ventrally, stout yellow bristles present medially; FHWR 1.0:4.5–1.0:5.0. Antenna brown to black; flagellum slightly longer than scape, FWLR 1.0:3.0–1.0:3.5. Frons yellow to brownish­yellow tomentose; longest setae as long as scape+pedicel combined. Occiput yellow to yellowish­gray tomentose with mostly white setae, sparse black setae sometimes present dorsally; 8 to 12 short, thick, black, postocular bristles present, two or three slightly arched forward, apex at or just before posterior margin of eye.

Thorax: Pronotum dorsally brown tomentose, setae yellowish, bristles black. Mesonotum black, postalar callus sometimes partly yellowish to red; two narrow, brown, paramedial, tomentose stripes and three brown, lateral spots present, tomentum elsewhere yellow to yellowish­gray posteriorly; vestiture black, sparse whitish setae present laterally and between dorsocentrals posteriorly; anterior setae slightly longer than scape; four long, thick lateral and four to five dorsocentral bristles present, latter present at or just behind transverse suture. Scutellum yellowish­gray tomentose with yellow setae. Pleuron yellow tomentose anteriorly, yellowish­gray posteriorly, anepisternum sometimes brown with sparse black setae; setae and bristles usually yellow; anepimeral bristle yellow or black. Halter yellow to reddish­yellow.

Wing ( Fig. 3a ): Yellowish­brown microtrichose. Cell r 1 wide apically, vein R 2+3 strongly curved forward apically. Cell r 4 with base just beyond apex of d cell; cell wide apically with vein R 4 strongly curved anteriorly before wing margin. Crossvein r­m before or just beyond middle of cell d, much longer than CuA 1 +M 3; cu­m sometimes present. Cell m 1 WR 1.0:3.0:2.8–1.0:4.7:4.8.

Leg: Coxae, trochanters and femora black. Coxae white tomentose with abundant white to yellow setae. Femora mostly short yellowish setose, long ventrally, latter sometimes black; fore and middle femora black setose dorsally; bristles usually black, often white to yellow in specimens in northern part of range, especially ventrally. HFWLR 1.0:4.0–1.0:5.0. Tibiae yellow with apices of first two blackish; hind tibia usually black on apical 1/2 anteriorly; bristles mostly black, two or three lateral bristles on fore and middle tibiae yellow. Tarsi with fore basotarsomere mostly yellow, apex brown; tarsomeres otherwise mostly brown, base of tarsomere three and four narrowly yellow; fore and middle tarsi, sometimes hind tarsus, with three to six yellow bristles.

Abdomen: Mostly yellowish­gray tomentose with yellow to white setae; terga 4 to 5 medially with sparse black setae, abundant on terga 6–8; bristles yellow or black, none especially stout.

Terminalia: Black to reddish­brown, apical margins reddish to yellowish. Cercus 2.5 to 3X longer than wide. Epandrium with prominently notched dorsoapically; apex narrow, dorsal corner usually angular in dorsal view. Gonostylus distinctive. Epiphallus, narrow in dorsal view, extends vertically just beyond middle; distiphallus wide apically; ejaculatory apodeme thin. Gonocoxite short, apex well before apical angle of epandrium; apical margin obtusely rounded in ventral view, evenly contured, not raised, and significantly shorter than anteromedial corner. Hypandrium round apically.

Female. Differs as follows. Body 9.7–15.3 mm; wing 7.0– 10.3 mm; FHWR 1.0:3.5– 1.0:3.7; FWLR 1.0:2.0–1.0:2.8; m 1 WR 1.0:2.9:3.0–1.0:4.6:4.2; HFWLR 1.0:4.6–1.0:5.6. Head: Face with black setae extending ventrally to or beyond middle of face and 12 or more black bristles. Thorax: Setae between dorsocentral rows posteriorly often black. Hind tarsus usually with only black bristles. Abdomen: Terga usually black setose dorsally. Unusually stout yellow and black bristles present on apical segments. Terminalia ( Figs. 21–24 ): Tergum 9 entirely sclerotized dorsally, about 1/3 as long as cercus. Sternum 8 without stout bristles. Spermatheca slightly enlarged and flattened apically, surface smooth. Genital fork distinctive.

Types examined. TANZANIA: 1 M [holotype Ommatius chiastoneurus Speiser ], Kilimandjaro, Sjostedt 1905–6, Kibonoto [Mkomazi Game Reserve] 1300–1900 m, 4 Dec ( NHRS) . SOUTH AFRICA: 1 M [holotype O. senex Bromley ], New Hanover [29°23’S 30°32’E], Natal, 16.xii.1913, C.B. Hardenberg ( NMSA) ; 1 M, [paratype O. senex Bromley ], New Hanover [29°23’S 30°32’E], Natal, 20.xii.14, C.B. Hardanberg, Bromley coll. ( USNM) .

Additional material. BURUNDI: 1 F, Urundi (Mosso) 1450 m, Makoronkwe 12.iii.1953, P. Basilewsky ( MRAC) . DEMOCRATIC REPUBLIC OF CONGO: 1 M, Zimbéze, Nova Choupanga , Prés Chemba, P. Lesne 1928 ( MNHN) ; 1 M, 1 F, Congo belge: P.N.A, Katanda , 950m 31.xi.1934, G.F. de Witte: 857 ( MRAC) ; 1 F, May ya Moto , 950m, 15.xi.1934, G.F. de Witte: 758 ( MRAC) . ETHIOPIA: 2 F, Abyssinie, Mission de Conchamps , C.H. Michel and M. Potter, 1899 ( MNHN) ; 1 M, Abyssinia , ix.1911, R. J. Stordy ( BMNH) . KENYA: 1 F, A prey on B, vi, Nairobi Dt [01°17’S 36°49’E], 1911, T. J. Anderson, 1911­384 ( BMNH) ; 1 M, Nairobi [01°17’S 36°49’E], B.E.A ~ G. Babault, iii.1943 ( MNHN) ; 1 M, Nairobi [01 °17S 36 °49E], B.E.A, vi–vii.1912, Dr. A.D. Milne ( MRAC) ; 1 F, Brit. E. Africa, Nairobi District [01°17’S 36°49’E], 3.v.1911, T. J. Anderson ( MRAC) ; 1 F, Ruwenzori, Mt Karangna , 8­9000 ft, xii.1934 – i.1935, F.W. Edwards ( BMNH) . MALAWI: 1 M, Nyasaland, Chikala District [14°38’S 35°12’E], i.1913, H. S. Stannus [male terminalia, slide 51] ( BMNH) . MOZAMBIQUE: 1 M, Prov. Gorongoza, Tendos du Sungoue, et Riy Vunduzi (alt 40 m), G. Vasse 1907 ( MNHN) . SOUTH AFRICA: 1 M, Mmbilo, Durban [29°48’S 31°00’E] Natal, 21.xi.26, A. L. Bevis ~ Ommatius senex, Bromley 1945 ? det S. W. Bromley ( BMNH) ; 1 M, Natal: Weenen [28°52’S 30°05’E], i.1925, (termalilia slide 50), H.P. Thomasset ( BMNH) ; 2 M, South Africa: Natal, Pietermaritzburg [29°36’S 30°23’E] 2930cb 19.iii.1978, JGH Londt ( NMSA) ; 2 M, 1 F, Dargle, Grassveld , 4400 ft 20.vii.1987, P.E. Reavell ( NMSA) ; 2 M, S.A. [=South Africa]: Natal: 2429AA, Transvaal, 20 km NE of Potgietersrus rd. to Maccapans Mts , 27.i.78, JGH Londt, long grass under tree ( NMSA) ; 1 M, Sth [=South] Africa Transvaal, Johannesburg [26°09’34”S 28°04’21”E], 2628 Aa, Highlands North, R. Elferink 21.ii.1982 ( NMSA) ; 1 M, Sth [=South] Africa Transvaal, Johannesburg [26°09’34”S 28°04’21”E], 2628 Aa, Highlands North, R. Elferink 7.iii.1982 ( NMSA) ; 1 M, S.A. [=South Africa] Natal, Pietermaritzburg [29°36’S 30°23’E], Scottsville, 15– 21.iv.1986, R. M. Miller, Malaise Trap ( NMSA) ; 1 M, S.A. [=South Africa] Natal, Durban [29°48’S 31°00’E] SE2931 CC, WW Strglingh Bluff, golf course 11.iv.87 ( NMSA) ; 1 M, S.A. [South Africa], Natal nr Itala [27°32’S 31°19’E], Game Reserve Graig Adam Dam 27°28’S 31°25’E, ii.1991 R. M. Miller, Malaise Trap ( NMSA) ; 1 M, S.A. [=South Africa]: Natal, Pietermaritzburg [29°36’S 30°23’E], Montrose in garden 2930 CB, JGH Londt , 12.xii.1981 ( NMSA) ; 1 M, 1 F, South Africa: Natal , 15 km SE Ingwavuma, 21.ii.1979 2732AA, JGH Londt, bushy area with big trees ( NMSA) . UGANDA: 1 M, Mafunga Forests, Kiozi , vi.1951, Van Someren. Com. Inst. Ent. Coll. No. 12301 ( BMNH) ; 1 M, Entebbe [0°04’N 32°38’E], 1–15.v.1983, G.G.M. Schulten ( ZMAN) ; 7 M, 7 F, Entebbe [0°04’N 32°38’E], Kisubi Forest , 9–10.v.1976, M.K. Paulus ( CNCI) ; 4 M, 3 F, Entebbe [0°04’N 32°38’E], Kisubi Forest , 8–9.vi.1976, M. K. Paulus ( CNCI) ; 1 F, Entebbe [0°04’N 32°38’E], Kisubi Forest , 24.iv.1976, M. K. Paulus ( CNCI) ; 2 M, Nr. Entebbe [0°04’N 32°38’E], 1–13.ii.1973, 1160 m, H. Falke ( CNCI) ; 19 M, 19 F, Entebbe [0°04’N 32°38’E], 10.iii.1972, in forest, H. Falke ( CNCI) ; 6 M, Entebbe [0°04’N 32°38’E], 10.iii.1972, in forest, H. Falke ( CNCI) ; 2 F, 7 mi. N. Entebbe [0°04’N 32°38’E], nr. Lk. Victoria, 2.iii.1972, 1135 m, H. Falke ( CNCI) ; 1 M, Entebbe [0°04’N 32°38’E], 10.iii.1972, in forest, H. Falke ( CNCI) ; 1 F, Uganda: Entebbe , 25.vi.1972, H. Falke ( FSCA) . ZIMBABWE: 1 M, among grass, Salisbury [= Harare 17°50’S 31°03’E], S. Rhodesia, Dept. Agric , 3.i.1937, A. Cuthbertson coll, Bromley coll. ( USNM) ; 1 M, S. Rhodesia, Dept. Agric , 28.i.1936, Bromley coll ( USNM) .

Distribution ( Tables 1, 2; Fig. 193). Wide spread in eastern Africa; collected up to 2647 meters from October to June

Remarks. Afroestricus chiastoneurus is distinguished from congeners by the combination of black femora and characters of the terminalia ( Figs. 15–24 ). Afroestricus chiastoneurus , A. macroscelis , A. insectaris , and A. varipes have black femora. However, the femora are entirely black in A. chiastoneurus and A. macroscelis whereas they are only partly black in the latter two species, i.e. brownish­yellow to brownish dorsally in A. varipes or yellow apically in A. insectaris . Females of A. chiastoneurus and A. macroscelis are essentially identical externally but each has distinctive genital forks ( Figs. 24 , 80 ).

Bromley (1936), uncertain of the identity of O. variabilis , described O. senex , a black South African species with black femora and terminalia. Apparently, he was not aware of A. chiastoneurus ( Speiser 1910) . My examination of the types of the two species reveals that they are conspecific. Since A. chiastoneurus was described earlier than O. senex , the former name has priority and is retained for the species. Ommatius senex is here declared a new synonmyn of A. variabilis .

Figures

FIGURES 15–24. Afroestricus chiastoneurus (Speiser). Male terminalia: 15–17. Lateral, dorsal, and ventral views. 18. Gonostylus. 19–20. Aedeagus, dorsal and lateral views. Female terminalia: 21–22. Dorsal and ventral views. 23. Spermatheca. 24. Genital fork with bulbus bursa and three spermathecal ducts.

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.

FIGURES 71–80. Afroestricus macroscelis (Bezzi). Male terminalia: 71–73. Lateral, dorsal, and ventral views. 74. Gonostylus. 75–76. Aedeagus, dorsal and lateral views. Female terminalia: 77–78. Dorsal and ventral views. 79. Spermatheca. 80. Genital fork.