Discomyza similis Lamb

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 : 22-25

Discomyza similis Lamb

Figs 34 , 58 , 60–68

Discomyza similis Lamb, 1912: 320 . Disney 1970: 250 (breeding); Mathis and Zatwarnicki 2003: 599 –600 (review, Seychelles).

Diagnosis. This species is similar to D. maculipennis and D. eritrea but can be distinguished from them and other congeners by the very short dark antennae.

Description. Body length 1.46–2.21 mm. Head ( Fig. 60 ). Head height-to-width ratio 0.76–0.83; frons height– to–width ratio 0.59–0.65; anterior part of ocellar triangle and lateral margin of frons shiny, mesofrons and the rest of ocellar triangle covered by sparse microtomentum; both fronto-orbital seta and a row of fine setulae above antennae present. Antenna black; basoflagellomere normal, 1.2x as long as wide; arista with 6–8 dorsal rays. Face ( Fig. 60 ) wrinkled, bearing 8 transverse folds, below antennae small spot of microtomentum; parafacialia black and shiny; facial width-to-head width ratio: 0.30–0.33; facial width-to-height ratio 0.52–0.67; gena-to-eye ratio 0.12– 0.22; eye width-to-height ratio 0.63–0.74. Palpus dark brown.

Thorax. Mesonotum greyish black, subshiny, laterad to scutellum bearing brown microtomentum; scutellum slightly longer than wide, trapezoidal. Wing ( Fig. 58 ) mostly hyaline with infuscated cell c1, most of cell r1, anterior margin of cell r2+3, and lateral margin of cell r4+5, and around crossvein dm-m; crossvein dm-m slightly sinuate; costal vein ratio 0.52–0.75; M vein ratio 0.70–0.88. Foretarsus black, 2 and 3 yellow, except of apical segments. Foreleg and mid- and hindfemora and tibiae black; tarsi of mid- and hindlegs yellowish, only apical tarsomeres of mid- and hindlegs blackish brown. Stem of halter dark grey, knob white.

Abdomen: Tergites medially greyish black and dull, laterally shiny and tergite 5 also shiny along posterior margin; tergites 1–4 with similar length, 5th tergite 1.3x longer than 4th. Male terminalia ( Figs 62–68 ). Epandrium in ventral view ( Fig. 62 ) 1.5x as wide as high with large cercal cavity, which is much higher than half of epandrial height; cercus in ventral view ( Fig. 62 ) quite slender, 4x higher than wide; large compared to other species; pregonostylus in ventral view ( Fig. 62 ) oval with attached baso-medial band, which form triangular-like sclerite, medial margin bearing 2 setae; postgonostyli ( Figs 63–66 ) asymmetrical, lacking large, thick mediosub-basal lobelike setae; left postgonostylus ( Fig. 63–64 ) V-shaped with bare lateral attachment and the main branch, setulose dorsalo-apically bearing ventral protrusion with 2 setae on 2/3 lenght; right postgonostylus ( Fig. 65–66 ) gradually becoming wider apically, generally setulose except for base and apex, antero-ventral margin on mid-lenght forming subrectangular projection with 2 large setae; aedeagus in ventral view ( Fig. 67 ) pentagonal with large and wide medio-lateral rounded lobes; aedeagus in lateral view ( Fig. 68 ) irregularly triangular with moderately rounded apex; phallapodeme in lateral view ( Fig. 68 ) as a curved triangle with a broad dorsal margin, which is attached to the aedeagus.

Type material. The male lectotype (designated by Mathis and Zatwarnicki, 2003: 599) is labeled “LECTO- TYPE ” (round label with a violet border), " Type H.T.” (round label with a red border”, “ Seychelles Is. Prof. J. S. Gardiner. 1914-537”, “ TYPE ” (blue label glued to the larger determination label), “ Discomyza similis Lamb det CGL” (except for the “ TYPE ” label, handwritten), “ LECTOTYPE ♂ of Discomyza similis Lamb, 1912 des. by Mathis & Zatwarnicki 2003 ”. The lectotype is double mounted (pin mounted in a paper-covered, rectangular block of cork with the number “142” handwritten on top and the label “ Mahe, '08-9. Seychelles Exp.” glued to the top, is in good condition, and is deposited in the BMNH. Additional three paralectotype males (two with "146" and one with "141") bears the same locality data.

Other material examined: ANGOLA: Cunene: Rocadas, Cunene R. (Malaise trap), 19–22. II. 1972, Southern African Expedition, 1 ♂ ( BMNH). CAMEROON: Kumba, 14. II.–8. III. 1968, R. H. L. Disney, 5 ♂, 8 ♀ ( BMNH); Sangmelima, 20 km E; Rt. N9, 7. XI. 1987, A. Freidberg, 1 ♀ ( USNM). D. R. CONGO: Eala, XI. 1934, J. Ghesquière, 1 ♀ ( USNM); Mbau, N. Kivu, 920m, 8–21. XII. 1971, H. Falke 1 ♀ ( CNC); Virunga National Park ("Parc. Nat. Albert”), Sake, 1500 m, 9–14. II. 1934, G. F. de Witte, 1 ♂, 1 ♀ ( MRAC). GHANA: Kumasi, Crop Res. Inst. (on soya beans), 2 ♀. KENYA: Diani Beach (ex decaying Achatina snail), VII. 1951, N. L. Krauss, 2 ♂, 2 ♀ (all BMNH); Diani Beach, 19. IX. 1985, L. Mahunka, L. Papp, 4 ♂, 1 ♀; Likoni Kilinelini Harbour, 20. IX. 1985, L. Mahunka, L. Papp, 1 ♂, 1 ♀ ( HNHM); Mombasa, 20 mi S; Malaise trap, 23–25. I. 1968, K. V. Krombein, P. J. Spangler, 2 ♂; University Ife, 10. VII. 1969, J. T. Medler, 3 ♂ ( USNM); Tsavo, 11–12. I. 1972, A. Freidberg, 1 ♀ ( BMNH). MADAGASCAR: Berenty Res., 20. IV. 1991, A. Freidberg, F. Kaplan, 6 ♀; Fort Dauphin (Taolanaro), 18–23. IV. 1991, A. Freidberg, F. Kaplan, 2 ♀; Fort Dauphin (50 km W; river), 20. IV. 1991, A. Freidberg, F. Kaplan, 2 ♀; Ifarantsa (20 km NW Fort Dauphin), 21. IV. 1991, A. Freidberg, F. Kaplan, 1 ♀; NosyBe (SE Lakobe Res; forest), 5. IV. 1991, A. Freidberg, F. Kaplan, 1 ♀; Nosy Tanikely, 6. IV. 1991, A. Freidberg, F. Kaplan, 2 ♀ (all USNM). MAURITIUS: Grand Gaube, 9. VI. 1971, A. M. Hutson, 1 ♀ ( BMNH). NAMIBIA: Otjozondjupa: Kombat, 1–6. IV. 1972, Southern African Expedition, 1 ♂ ( BMNH). NIGERIA: Office for the Protection of Research Subjects ( O P R S) (ex. Snail shell), 30. VII. 1951, J. L. Gregory, 1 ♀; Bauchi State, Yankari Game Reserve Wikki env., Wikki falu szelen, 15. VIII. 1978, L. Demeter András, 1 ♀ ( HNHM); Ibadan, Malaise trap, 25. I.–27. II. 1963, D. C. Eidt, 2 ♂, 2 ♀, 4–20. VII. 1962, 3 ♂, 4 ♀ ( CNC); Ile-Ife, 14. VIII. 1969, J. T. Medler, 1♂, 1 ♀; 10. VII. 1969, 1♀ ( BMNH). R. SOUTH AFRICA: Eastern Cape: Somerset East, X. 1930, R. E. Turner, 1 ♂ ( BMNH); Gauteng: Pretoria, ARC, Plant Prot. Inst. Rami campus, yellow pan traps, 3–6. XII. 2006, I. Mik, G. Melika, 2 ♂ ( HNHM); KwaZulu-Natal: Pietermaritzburg, Bloemendal Farm, host: Gyanisa maja (Klug), larva ( Lepidoptera : Saturniidae ), IV. 1961, 4 ♂, 2 ♀ ( USNM); Mpumalanga: TVL, Kruger National Park, Skukuza, 24.59S, 31.35E, 292 m, Malaise trap, 18–21. I. 1984, C.D. Eardley, 1 ♂ ( PPRI); Western Cape: Mossel Bay, X. 1933, R. E. Turner, 1 ♂ ( BMNH). SEYCHELLES: La Digue: Anse Sévère, 12. V. 1997, W. N. Mathis, 1 ♂. La Passe, 14. V. 1997, W. N. Mathis, 1 ♂. La Réunion, 14. V. 1997, W. N. Mathis, 1 ♀. Mah: Airport, 7–8. IV. 1986, W. N. Mathis, 1 ♂, 2 ♀; Anse aux Courbes, 3. V. 1997, W. N. Mathis, 20 m, 14 ♀; Anse aux Pins, 2. IV. 1986, W. N. Mathis, 1 ♂, 1 ♀; Anse Nord D'est, 5. V. 1997, W. N. Mathis, 2 ♂; Anse Royale, 6. V. 1997, W. N. Mathis, 1 ♀ (all USNM); Beau Vallon, 10–11. V. 1965, W. H. T. Tams & Nye, 1 ♀ ( BMNH); Bel Ombre, Corsaire, 3–18. V. 1997, W. N. Mathis, 1 ♀; Fond de L'Anse, 11. V. 1997, W. N. Mathis, 1 ♂, 1 ♀; Machabee, 5–6. IV. 1986, W. N. Mathis, 1 ♀; Police Bay, 16. V. 1997, W. N. Mathis, 1 ♀; Roche Caiman Bird Sanctuary, 7. V. 1997, W. N. Mathis, 1 ♀; Victoria, Botanical Garden, 4. IV. 1986, W. N. Mathis, 4 ♀. Praslin: Cote D'Or, 9. V. 1997, W. N. Mathis, 1 ♀ (all USNM). SIERRA LEONE: Freetown, Cape Sierra Hotel area, swept along roadsides, 1317' W, 831' N, 18–23. XI. 1993, L. Cederholm, R. Danielsson, R. Hall, 1 ♂, 1 ♀ ( ZMLU). UGANDA: Ankole Kichwamba, 23. IV.–5. V. 1968, P. J. Spangler, 1 ♂, 1 ♀ ( USNM); Bwamba, VI. 1976, E. Balyetangara, 1 ♀; 7 mi. N. Entebbe 1135 m, 5. XI. 1972, H. Falke, 2 ♂ ( CNC); Kampala-Muyenga Hill, 26. III. 1973, H. Gonget, 1 ♀ ( ZMUC). YEMEN: Jabel Jihaf, ca. 2200 m, 19. IX. 1937, H. Scott & E. B. Britton, 1 ♀; X. 1937, 2 ♂. ZAMBIA: Lusaka (dead snail Limicolaria ), R. A. Beaver, 25–26. I. 1979, 1♂, 2 ♀. ZIMBABWE: Victoria Falls, rain forest, 29–30. IV. 1972, 1 ♀ (all BMNH).

Distribution ( Fig. 34 ): Afrotropics: Cameroon, D. R. Congo, Kenya, Madagascar, Nigeria, R. South Africa, Seychelles (La Digue, Mahé, Praslin), Uganda, Yemen, Zambia, Zimbabwe.

Figures

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

FIGURES 57 – 59. Wings and head with mesonotum. 57. Wing of Discomyza maculipennis. 58. Wing of Discomyza similis. 59. Head with mesonotum of Discomyza maculipennis, dorsal view. Scale bar 0.5 mm.

FIGURES 60 – 61. Head of Discomyza similis. 60. General view, anterior view. 61. Details in the central part, anterior view. Scale bar 0.5 mm.

FIGURES 62 – 68. Hypopygium of Discomyza similis. 62. External male terminalia (epandrium, cerci and pregonostyli), ventral view. 63 – 64. left postgonostylus. 63. ventral view. 64. lateral view. 65 – 66. right postgonostylus. 65. ventral view. 66. lateral view. 67 – 68. Phallapodeme and aedeagus. 67. ventral view. 68. lateral view. Scale bar 0.1 mm.