Gymnochiromyia capensis, Ebejer, 2008

Ebejer, M. J., 2008, New species of Gymnochiromyia Hendel, 1933 (Diptera: Schizophora: Chyromyidae) from Southern Africa, African Invertebrates 49 (1), pp. 77-77 : 87-89

Gymnochiromyia capensis sp. n.

Figs 5–7

Etymology: Named after the former Cape Province of South Africa.

Diagnosis: This is one of the smaller species in the genus and exhibits significant chromatic variation; msn with 3–4 stripes (middle pair may be coalescent), dark brown mtn, hypl and ep; the larger setae on head and thorax vary from brown to dark brown; abdomen with shiny brown tergites.

Description:

Male.

Head: Yellow except for black oc triangle; fr protruding above antennae, about half width of head, narrowed anteriorly, at level of antennae 0.7 width at level of anterior oc and 0.7 width of one eye viewed from in front. Gena in profile a little narrower anteriorly, depth below middle of eye about 0.8 eye height, yellow and pale haired. ocp in profile not visible behind eye; with short postocular setulae in an irregular row; isolated lower post-genal seta present, but small and indistinct. Mouthparts small and yellow; buccal margin with long setulae. Face poorly sclerotised, depressed with a shallow linear median carina. Antenna yellow, second segment paler with distinct short dark seta dorsally; third segment round, finely pubescent: hairs not as long as diameter of arista at base; arista almost entirely dark and completely bare. Chaetotaxy: 3 strong orbs, the anterior inclinate; distance between middle and posterior orb almost twice that between anterior and middle; pvt well-developed and crossed, about half length of hind orb; 1 vti and 1 vte; oc proclinate and divergent; about 8 short setulae across middle of fr. All setae and setulae yellow.

Thorax (description supplemented with reference to paratypes because type is pinned through posterior msn and part of scut): msn with a brownish pattern consisting of a rounded spot behind hu, confluent with a stripe reaching as far back as wing base and with a pair of broad stripes in the middle between the dc lines; stripes tend to be darker posteriorly and behind hu lateral stripes, those between dc and ia lines may extend to lateral margin of scut; scut yellow; posterior third of stpl especially at upper [posterior] corner and hypl brown; mtn dark brown. Chaetotaxy: 1 hu with adjacent setula, 1 psthu, 2 ntpl, 1 sa, 1 pa, 1 dc with a shorter one in front of it, acrs in 6 irregular rows, 1 pair of prescutellars; 1 mspl and 1 stpl.

Wing: Hyaline, veins yellow, distance on costal margin between R 2+3 to R 4+5 is 0.7 that between R 4+5 and M 1+2; distance between crossveins equal to 0.6 length of apical section of Cu. Haltere yellow.

Legs: Not modified except for slightly thicker femora; fine setulae scattered on all pairs of legs in addition to longer setae on fore femur; claws and pulvilli normal.

Abdomen: tg brown, a little shiny; longer setae on tg 4 and 5 laterally, setae pale and about as long as tg.

Postabdomen: tg 6 unusually large for the genus, about 0.8 length of ep; cerci, in profile, appear rounded apically; ep distinctly angled at lower posterior corner with surs embedded in fold, angled and blunt at tip, curved medially; hyp small; ph apd and ej apd not clearly identified; prg trapezoidal, slightly curved with setae on inferior surface; psg projecting from behind and medial to surs; distiphallus a little broader apically.

Female.

Similar to male, but larger and somewhat darker; distance between cross veins almost equal to length of apical section of Cu; tg may be darkened only along midline, with apical 2 tg often darkest. Postabdomen ( Fig. 7 ) with paired plates of st 8 of characteristic shape with lobulated margins and invaginated fold caudally.

Length: ♂ 1.2 mm, wing 1.3 mm; ♀1.6 mm, wing 1.9 mm.

Variation: The extent of darkening of msn stripes and tg varies from almost completely yellow to dark brown; in the male paratype from Namibia, the middle msn stripes are fused into one; setae and setulae can also be dark brown in the darker forms; some males have ep almost completely dark brown except for lower margin.

Holotype: ♂ SOUTH AFRICA: Western Cape: Knersvlakte north of Vanrhynsdorp , 6–9.x.1964, B. & P. Stuckenberg ( NMSA, 1178 ).

Paratypes: SOUTH AFRICA: Western Cape: 1♀same data and depository as holotype; 1 ♂ Mossel Bay, 5– 31.vii.1921, R.E. Turner (Brit. Mus. 1921-315) ( NHML) ; 1♀Mossel Bay, vi–vii.1930, R.E. Turner (Brit. Mus. 1930-402) ( NHML) ; 1 ♂ 1♀Atlantic coast, Ysterfontein , 20.x.1964, B. & P. Stuckenberg ( NMSA) ; 1 ♂ Strandfontein coast west of Vanrhynsdorp , 15–17.x.1964, B. & P. Stuckenberg ( NMSA) ; 1♀Bredasdorp District, Arniston coastal dunes, 22–23.x.1964, B. & P. Stuckenberg ( NMSA) ; 1 ♂ 1♀Saldanha, 8–9.x.1977, Malaise trap, R.M. Miller ( NMSA) ; 1 ♂ 1♀same data ( NMC) ; 1 ♂ 1♀Laaiplek, 9.x.1977, Malaise trap, R.M. Miller ( NMSA) ; 1 ♂ 1♀same data ( TAU) ; 1 ♂ Strandfontein, Groot-Sandleegte , 12.x.1977, Malaise trap, R.M. Miller ( NMSA) . Eastern Cape: 2♀Van Stadens Pass, 29.x.1964, B. & P. Stuckenberg ( NMSA) . NAMIBIA: Lüderitz District: 1 ♂ Skorpion area , 27º49'S: 16º36'E, 9.viii.1997, beating/sweeping, A. KirkSpriggs & E. Marais ( NMNW) ; 1♀Rooiberg, 27º38'S: 16º28'E, 22–24.ix.1997, Malaise trap, A. Kirk-Spriggs & E. Marais ( NMNW) ; 2♀Tsaus, 27º10'29"S: 16º07'06"E, 24–26.ix.1997, in alcohol, E. Marais & A.H. Kirk-Spriggs ( NMNW) .

Figures

Figs 5, 6. G. capensis sp. n.: (5) male hypopygium, lateral view; (6) head, lateral view. Scale bars = 0.2 mm.

Fig. 7. G. capensis sp. n., female postabdomen, ventral (a) and lateral (b) views, and (c) spermatheca. Scale bar = 0.15 mm.