Aphaniosoma fissum Collin, 1949

Ebejer, Martin J., 2009, A revision of Afrotropical Chyromyidae (excluding Gymnochiromyia Hendel) (Diptera: Schizophora), with the recognition of two subfamilies and the description of new genera, African Invertebrates 50 (2), pp. 321-321 : 393-396

Aphaniosoma fissum Collin, 1949

Figs 39 , 40

Aphaniosoma fissum: Collin 1949: 138 .

Collin (1949) described several species from an inland oasis in northern Egypt. Since then, several of them have been found in the Middle East and fissum is here confirmed from sub-Saharan Africa. Although Collin illustrated the male postabdomen, he did not give enough detail to enable reliable identification, given the many new similar species described since. Hence, a more detailed description and illustrations of the postabdomen of both sexes are presented below.

Diagnosis:Very variable in colour, but predominant form yellow with longitudinal stripes on scutum becoming dark and confluent anteriorly in some specimens or being pale brown and restricted to behind scutal suture in others. Area in front of scut yellow, but sometimes with small dark midline spot abutting suture with scut; yellow fr and antennae, abdomen yellow or with brown tg having yellow hind margins, sometimes tg all yellow, tg 6 with small posteroventral lobe, tarsomere 5 yellow or brown; male postabdomen with clearly visible yellow surs and prg; female sometimes with distal 3 tarsomeres darkened. distiph black at apex, otherwise hypopygium overwhelmingly yellow.

Redescription:

Male.

Head: Yellow, ocp dark brown except for broad yellow postocular margin and wedgeshaped area from vertex to neck, oc triangle black, fr broad, but converging anteriorly so that at level of antennae about 0.7 as wide as at level of anterior oc, face small, depressed and with distinct, narrow but low facial carina, eye oval lying oblique, gena yellow, at middle about 0.7 height of eye and having numerous yellow setulae, 2 short setae at vibrissal corner, mouthparts yellow except for two small brown spots deep to proboscis and anterior margin of roof of buccal cavity, 2 pairs of setulae on fr, one of which, slightly longer in front of oc triangle, 4 short orb getting progressively shorter from back to front, 1 vti and 1 vte, pvt distinct and convergent, ocellars long, divergent, antenna yellow, most of second segment of arista dark.

Thorax: Scutum and scut with yellow ground but with 6 dark grey longitudinal stripes on scutum confluent anteriorly, only the 2 lateral stripes becoming separated posteriorly, scut a little greyish on disk, mtn entirely dark grey, postpronotal lobe and ntpl yellow, pleura mostly dark grey, but for broad yellow margins to sutures, whole of anepimeron and posterior half of anepisternum chaetotaxy: 1 pprn, 1 posthu, 1 ihu, 2 ntpl, 0+4 ia, 1+4 acrs, 4+5 dc only the posterior one well-developed, prpl distinct, 1 pa, 2 pairs of marginal scut, 1 katepisternal with shorter seta in front and several setulae on anterior part of sclerite, 1 anepisternal, all setae pale yellow to pale brown.

Wing: Hyaline and uniformly microtrichose, veins pale brown, distance between R 2+3 to R 4+5 on costal margin about 0.5 that between R 4+5 and M 1+2, distance between crossveins about 1.3× length of posterior crossvein and length of apical section of Cu about 2.2× length of posterior crossvein. Haltere yellow.

Legs: Yellow and fine yellow setulose, tarsomere 5 of all legs brown.

Abdomen: Brown with narrow, pale yellow hind margins to all tg, especially on sides. Postabdomen:Yellow with distinctly visible yellow surs and finely setulose prg adjacent to black ph structures.

Female.

As male, but several specimens have tarsomeres 3 and 4 also darkened. Postabdomen: tg 7 narrowly divided dorsally; st 7 with lateral and central sclerotized plates; 8 of curious shape and closely attached to cerc; hypr membraneous.

Length: ơ body 1.0 mm, wing 1.0 mm; ^body 1.2 mm, wing 1.3 mm.

Material exmained: KENYA:2ơ 5^Tsavo National Park , Voi R., 22.ii.1971, M. von Tschirnhaus (in alcohol, FBUB) ; 1ơ same data (in glycerine, MJE) ; 1ơ 3^same data (in alcohol, NMWC) ; 1ơ Hunter’s Lodge , 02°13'S: 37°43'E, 13–16.ix.2005, A. Freidberg ( TAU) . NAMIBIA: 4ơ 2^Lüderitz District, Angra Bay , 26°37'11"S: 15°11'42"E, sweeping lush vegetation at effluent run-off stream, 27.iii.1998, A.H. Kirk-Spriggs ( NMNW) ; 27ơ 19^Khorixas District, Huab R. at Krone 721, 20°37'09"S: 13°54'31"E, sweeping grasses and sedges, 23–26.x.1998, A.H. Kirk-Spriggs ( NMNW) ; 1ơ 3^same data (in alcohol, NMWC) ; 4ơ 2^Khorixas District , Gai-As spring, 20°46'01"S: 14°01'12"E, 22.x.1998, A.H. Kirk-Spriggs & E. Marais (in alcohol, NMWC) ; 1ơ Omaruru District, Brandberg Wes salt spring, 20°56'51"S: 14°07'28"E, sweeping marginal grasses and sedges, 23–26.x.1998, A.H. Kirk-Spriggs & E. Marais (in alcohol, NMWC) ; 1ơ 3^Khorixas District, Huab R. at Krone 721, 20°37'09"S: 13°54'31"E, sweeping grasses and sedges, 23– 26.x.1998, A.H. Kirk-Spriggs (in alcohol, NMNW) ; 1ơ Khorixas District, Huab R. at Vrede 19, 20°24'00"S: 14°10'16"E, 26.x.1998, swept from fresh elephant dung, A.H. Kirk-Spriggs ( NMNW) ; 1^Skeleton Coast Park , Kunene R. mouth, 17°15'97"S:11°46'83"E, sweeping marginal grasses and reeds on flood plain, 17– 18.iii.1998, A.H. Kirk-Spriggs ( NMNW); 1^Brandberg, Messum Valley, alt. 700 m, 21°13'29"S:14°30'98"E, 3.iv.1999, S. van Noort & S.G. Compton, Malaise trap, Bushy-Karoo-Namib shrubland (in alcohol, NMWC) ; 1ơ Kahn R., 8 km N Usakos, 30–31.i.1972, Southern African Expedition (29) B.M. 1972–1 ( BMNH) ; 2ơ 1^nr Onseepkans, Orange R. banks, 8–10.i.1972, Southern African Expedition (W1) B.M. 1972–1 ( BMNH) ; 1ơ 1^Walvis Bay, 25–26.i.1972, pool edge in dunes, Southern African Expedition (W24) BM 1972–1 ( BMNH) ; 73ơ 114^Swakopmund, general sweeping, 26–30.i.1972, Southern African Expedition (W25) BM 1972–1 ( BMNH) ; 2ơ 4^Swakopmund, swept vegetation around sewage farm settling tanks, 26– 30.i.1972, Southern African Expedition (W25) BM 1972–1 ( BMNH) ; 12ơ 8^Walvis Bay, pool edge in dunes, 25–26.i.1972, Southern African Expedition (W27) BM 1972–1 ( BMNH) ; 1ơ Otjitambi farm, 47 km ESE Kamanjab, 13–15.ii.1972, Southern African Expedition (W37) BM 1972–1 ( BMNH) ; 1^Onguma farm, 55 miles NW Tsumeb, 17–19.ii.1972, Southern African Expedition (W43) BM 1972–1 ( BMNH) ; 1^Lüderitz District, Agate Beach , 10 km N Lüderitz, alt. 3 m, low coastal vegetated dunes, 18.ii.1974, M.E. and B.J. Irwin ( NMSA) ; 1ơ 2^Lüderitz , alt. 20 m, 14.ix.2003, A. Freidberg ( TAUI) ; 1ơ 1^Orange R., 25 km Rosh Pinah , 28°05'S: 16°24'E, 15.ix.2003,A. Freidberg ( TAUI) . SOUTH AFRICA: Western Cape: 1ơ Sandfontein Coast, west of Van Rhynsdorp , 15–17.x.1964, B. & P. Stuckenberg ( NMSA) .

Distribution: Middle East, Egypt, Kenya, Namibia, South Africa.

Figures

Fig. 39. Aphaniosoma fissum Collin, ơ: (a) tg 6, lateral; (b) st 6, ventral; (c) hypopygium, lateral. Scale bars = 0.15 mm.

Fig. 40. Aphaniosoma fissum Collin, ^postabdomen: (a) posterior, (b) lateral, (c) spermathecae. Scale bar = 0.15 mm.