Discomyza dolichocerus Cresson

Discomyza dolichocerus Cresson

Figs. 12–21, 23

Discomyza dolichocerus Cresson, 1944: 5.

Discomyza obscuricornis Canzoneri and Rampini, 1996: 10, new synonym.

Diagnosis. This species is similar to D. fagomoga sp. nov., but can be distinguished from it by longer antennae (length of basoflagellomere 4.3x as long as wide), and narrower transverse band around crossvein dm-m.

Description. Body length 1.80–2.29 mm. Head (Fig. 13). Head height-to-width ratio 0.79–0.83; frons heightto-width ratio 0.43–0.45; parafrons shiny, mesofrons dull with ocellar triangle subshiny; anterior fronto-orbital seta absent. Antenna yellow; basoflagellomere elongated, 4.3x as long as wide; arista with 9 dorsal rays. Face (Fig. 14) black and shiny, bears vertical ridges in 4 irregular horizontal series, weakened ventrad; just below antennae small white microtomentose areas; 3 short and 2 longer facial setae; parafacialia silvery white microtomentose; facial width-to-head width ratio 0.29–0.34; facial width-to-height ratio 0.51–0.59; gena-to-eye ratio 0.16–0.18; eye width-to-height ratio 0.58–0.67. Palpus dark brown.

Thorax. Mesonotum greyish black, subshiny; scutellum trapezoidal. Wing (Fig. 23) infuscated along anterior margin limited by vein R4+5, continued to apical 1/6 of cell r4+5; also transverse band around crossvein dm-m, which extends anteriorly in cell r4+5, its posterior margin tapered; crossvein dm-m slightly arcuate; costal vein ratio 0.62– 0.66; M vein ratio 0.91–1.02. All legs except tarsi black, fore basitarsomere whitish yellow, mid and hind 1–4 tarsomeres yellowish, other blackish brown. Distal half of forefemur bearing anteroventral comb-like row of setulae. Stem of halter dark grey, knob white.

Abdomen: Tergites 1–4 greyish black and dull, tergite 5 shiny; tergites with similar length. Male terminalia (Figs 15–21). Epandrium in ventral view (Fig. 15) only slightly wider than high, cercal cavity is moderate, little higher than half of epandrium; cercus in ventral view (Fig. 15) semicircular, twice as high as wide; pregonostylus (Fig. 15) in ventral view irregularly oval with posterior margin concave, medial margin bears 2 setulae, which are smaller than those on epandrium and cercus; postgonostyli (Figs 16–19) asymmetrical, bearing large, thick mediosub-basal lobe-like setae; right postgonostylus slightly longer than left; left postgonostylus in ventral view irregularly triangular with subdistalo-lateral projection (Figs 16–17), in lateral view irregularly rectangular bears in distal portion three projections; right postgonostylus (Figs 18–19) in ventral view reniform, strongly narrow in 1/3 of distal portion; right postgonostylus in lateral view elongated, gradually tapered, bears large lateral incision in the middle of its length; aedeagus in ventral view (Fig. 20) narrow and elongate bearing subbasal long and moderately rounded projections; aedeagus in lateral view (Fig. 21) narrowly triangular with submedio-dorsal triangular projection; phallapodeme in lateral view (Fig. 21) semicircular.

Type material: Holotype male is double mounted, is in good condition (left fore leg glued on paper; half of abdomen removed and stored in plastic microvial) and is labeled: “HOLO-TYPE” (round with red margin), “H J A Turner Naivasha 7 37”, “ 1228 I. C. M.”, “ Discomyza dolichocerus Cresson det Wirth” (name and author handwritten), “this is apparently the holotype which was not returned” (handwritten), “Pres. by Com. Inst. Ent. B. M. 1954-110” preserved in BMNH. Naivasha is a city located in Kenya. The holotype male of the junior synonym is double mounted, is in excellent condition and is labelled: “ Sierra Leone: Freetown Cape Sierra Hotel area 1317'W, 831'N 23. XI. 1993 loc 2 swept along roadsides (printed), “Lund University Sierra Leone Expedition 1993 leg L. Cederholm—R. Danielsson—R. Hall (printed), “ HOLOTYPUS ♂ Discomyza obscuricornis nov. det. Canzoneri S. det. Rampini L. (red label, sex sign and the name handwritten), “ ZML 1998 397 (orange label, printed) and is preserved in MZLU.

Other material examined: D. R. CONGO: Upemba National Park: Kabwekanona reg. Lusinga, 1815 m, 25. IV. 1949, G. F. de Witte, 1 ♂; Katwi af dr. Lutwa, 1780 m, 5. III. 1948, G. F. Witte, 2 ♂, 1 ♀; Mukana, 1810 m, 6. III. 1948, G. F. De Witte, 1 ♂, 2 ♀; Virunga National Park (“PNA”): N. lac Kivu Ngoma, 2/ 6. II. 1936, H. Damas, 1 ♀ (MRAC). KENYA: Gilgil, 15. XI. 1986, A. Freidberg, 1 ♂, 1 ♀; Ngong Forestry Station, 13–18. I. 1968, K. V. Krombein, P. J. Spangler, 1 ♀. MALAWI: Center Nchisi Forest, 1500–1700 m, 17–18. IX. 1989, A. Freidberg. F. Kaplan, 1 ♀ (USNM). UGANDA: 7 mi. N. Entebbe 1135 m, 5. XI. 1972, H. Falke, 1 ♂ (CNC); Kasese, 10 km N, 1600 m, 4. I. 1996, I. Yarum, A. Freidberg, 1 ♀ (USNM).

Distribution (Fig. 12): Afrotropics: D. R. Congo, Kenya, Malawi, Rwanda, Sierra Leone, Uganda.

Remarks. Canzoneri and Rampini (1996) proposed D. obscuricornis as a separate species from D. dolichocerus base on different coloration of the basoflagellomere. The holotype of D. obscuricornis agrees with the original description in having the basoflagellomere reddish at the base and the rest brownish-black. Coloration of the antennae are characteristic for D. dolichocerus. Perhaps Canzoneri and Rampini (1996) compared their species with the material from D. R. Congo, where the more common species there is described below and has a completely reddish antennae.