Discomyza eritrea Cresson

Zatwarnicki, Tadeusz & Cielniak, Magdalena, 2015, A review of the genus Discomyza (Diptera: Ephydridae) from Afrotropical, Australasian / Oceanian and Oriental Regions, Zootaxa 3963 (1), pp. 1-26 : 11-14

Discomyza eritrea Cresson

Figs 25–34 , 44

Discomyza eritrea Cresson, 1939: 3 .

Discomyza intermedia Canzoneri and Meneghini, 1969: 184 , new synonym.

Diagnosis. This species is similar to D. maculipennis but can be distinguished from it by uniformly black thorax, lacking a pattern of microtomentum.

Description. Body length 2.42–2.80 mm. Head ( Fig. 25 ). Head height-to-width ratio 0.67–0.72; frons wide, frons height-to-width ratio 0.49–0.54; ocellar triangle and parafrons shiny, white microtomentum of lunate shape above antennae and rounded spot antero-medial to orbital setae; both fronto-orbital setae present. Antenna yellow; dorsal 1/3 of basoflagellomere darkened; basoflagellomere normal in length, 1.8x as long as wide; arista with 7–9 dorsal rays. Face ( Fig. 26 ) rugose, 5–6 transverse folds in the middle, series of 6 depressions laterally, above antennae shiny, but medially with whitish microtomentum; 4–6 short facial setae; dorsal part of parafacialia is shiny, then along the eye covered by white microtomentum; facial width-to-head width ratio 0.35–0.37; facial width-to-height ratio 0.79–0.82; gena-to-eye ratio 0.13–0.16; eye width-to-height ratio 0.50–0.70. Palpus dark brown.

Thorax. Mesonotum greyish black, subshiny; scutellum semicircular, shiny, laterad with brownish microtomentum. Wing ( Fig. 44 ) infuscated along anterior margin in front of vein R4+5, then gradually more hyaline posteriorly in cell r4+5, also transverse band around cross-vein dm-m; crossvein dm-m straight; costal vein ratio 0.59–0.68; M vein ratio 1.09–1.16. Foreleg and mid- and hindfemora and tibiae black; tarsi of mid- and hindlegs yellowish, only apical tarsomeres of mid- and hindlegs blackish brown. Distal half of forefemur bearing 2 anteroventral comb-like setulae. Stem of halter dark grey, knob white.

Abdomen: Tergites 1–4 greiysh black and dull, tergite 5 shiny; tergites with similar length. Male terminalia ( Figs 27–33 ). Epandrium in ventral view ( Fig. 27 ) 1.4x wider than high, with comparatively narrow arms and very large cercal cavity, which height is about 0.9 of epandrial height; cercus in ventral view ( Fig. 27 ) lunate, 4x higher than wide; pregonostylus ( Figs 27 ) reduced, in ventral view as transversal band-like sclerite; postgonostyli ( Figs 28–31 ) asymmetrical, lacking large, thick mediosub-basal lobe-like setae; left postgonostylus ( Figs 28–29 ) irregularly oval with numerous setulae on distal portion; right postgonostylus ( Figs 30–31 ) finger-like, setulose mostly on lateral margin of distal part and 2 long setae on medial margin; aedeagus in ventral view ( Figs 32 ) elongate, cigar-like with small medio-lateral folds; aedeagus in lateral view ( Figs 33 ) narrow and slightly sinuate, bearing submedio-dorsal elongate projection; phallapodeme in lateral view ( Figs 33 ) semicircular.

Type material: Holotype male of senior synonym is in very good condition labelled: “Holo-type” (round label with red margin), “ SUDAN GOVT Port Sudan, Ch. S. Insp. 2. 2. 38 larvae from shells at Flamingo Bay” (from Port handwritten), “Ent. Coll. C/8983” (number handwritten), “Coll. 8983” (handwritten), “ Type Discomyza ERITREA E. T. Cresson, Jr. ♂” (carmine; name and sex sign handwritten). Allotype female labelled: “ Type ” (round label with red margin), “ SUDAN GOVT Port Sudan, Ch. S. Insp. 2. 2. 38 larvae from shells at Flamingo Bay” (text from Port handwritten), “Ent. Coll. C/8984” (number handwritten), “Coll. 8984” (handwritten), “ Type Discomyza ERITREA E. T. Cresson, Jr. female sign” (pink; name and sex sign handwritten), “Pres. By Com. Inst. Ent., B. M. 1954-110”. Two paratypes (a male and a female) with same locality label and differs in blue label bears PARATYPE and a sex sign. All are preserved in BMNH. Holotype female of junior synonym is double mounted with good condition (some apical tarsomeres missing and part of the head is covered by dust), labelled: “ HOLOTYPUS ” (beige printing) “ Congo belge: P. N.A. riv. Molindi, entre Kirumba - lac. Kibuga 1000 m. 31-iv au 2-v-1934 G. F. de Witte: 393”, “ COLL. MUS. CONGO (ex. Coll. I. C. N. P. B.)”, “ Holotypus Discomyza intermedia sp. n. ” (red, name handwritten) is preserved in MRAC.

Other material examined: BOTSWANA: Serowe Farmer's Brigade, Malaise trap, VIII. 1991, P. Forchhammer, 3 ♂, 2 ♀; IV.–VII. 1991, 1 ♂, 2 ♀; I.–III. 1992, 1 ♂, 2 ♀; V.–VI. 1992, 1 ♂, 1 ♀ ( NMSA). D. R. CONGO: Garamba National Park, de Saeger, 3. VII. 1951, J. Verschuren, 1 ♂; Upemba National Park: Dioidi (1700 m), 22. IV. 1947, G. F de Witte, 1 ♀ (all MRAC). ERITREA : Assab, I–III. 1907, G. Katona, 1 ♂, 3 ♀; VII. 1907, 4 ♂ ( HNHM). KENYA: Rt 109, Kibwezi, 200 km SE Nairobi, 2–7. XII. 1989, A. Freidberg, F. Kaplan, 1 ♂, 1 ♀; Rt B8, near Takaungu, 50 km N Mombasa (S 03º42', E 39º49'), 12. VIII. 2003, A. Freidberg, 2 ♂. MOZAMBIQUE: Luabo Lower Zambezi River, Port East Africa, XII. 1957, P. J. Usher, 1 ♂ (all USNM). NAMIBIA: Kunene: Opuwo Dist., 35 km E Epupa, Kunene Riv., 17º03'37” S, 13º29'32” E, shaded woodland, Malaise trap, 9– 11. X, 1999, A. H. Kirk-Spriggs, T. Pape, W. Hauwanga, 1 ♀; Zambezi: Katima Mulilio, Salambala pan, 17º50'00” S, 24º35'58” E, Malaise trap, 1–4. III. 2001, A. H. Kirk-Spriggs, 1 ♀ ( NMNW, on loan at USNM). SUDAN: Port Sudan, ex Trochus shells (Mollusca, Trochidae ), 4. I. 1980, 1 ♂, 1 ♀, dead Trochus , 7. XI. 1945, A. K. Abdalla, D. J. Lewis, 3 ♂, 2 ♀. TANZANIA: Dar es Salaam, VII. 1969, P. Ard ӧ, 1 ♀ (all BMNH).

Distribution ( Fig. 34 ): Afrotropics: Botswana, D. R. Congo, Ethiopia, Eritrea , Ghana, Kenya, Mozambique, Namibia, Sudan and Tanzania.

Remarks. Canzoneri and Meneghini, 1969 described their species as an intermediate between D. dolichocerus and D. similis and compared it with D. similis . They overlooked D. eritrea in making their comparisons and diagnosis.

Figures

FIGURE 34. Distribution map of Discomyza eritrea and Discomyza similis.

FIGURES 25 – 26. Head of Discomyza eritrea. 25. General view, anterior view. 26. Details in the central part, anterior view. Scale bar 0.5 mm.

FIGURES 27 – 33. Hypopygium of Discomyza eritrea. 27. External male terminalia (epandrium, cerci and pregonostyli), ventral view. 28 – 29. left postgonostylus. 28. ventral view, 29. lateral view. 30 – 31. right postgonostylus. 30. ventral view, 31 lateral view. 32 – 33. Phallapodeme and aedeagus. 32. ventral view. 33. lateral view. Scale bar 0.1 mm.

FIGURES 44 – 46. Wings and head with mesonotum. 44. Wing of Discomyza eritrea. 45. Wing of Discomyza fagomoga sp. nov. 46. Head with mesonotum of Discomyza fagomoga sp. nov., dorsal view. Scale bar 0.5 mm.