Gymnochiromyia balteata sp. n.

Figs 2d, 3, 4

Etymology: From Latin balteus (belt). The name refers to the dark metanotum contrasting with the pale thorax and abdomen, giving the appearance of a belt around the waist of the insect.

Diagnosis: msn completely yellow without any markings, acrs in 8 rows, mtn and hypl at base of haltere dark; ♂ with brown spot on ep, ♀abdomen all yellow, without dark spots.

Description:

Male.

Head: fr yellow with margins slightly convergent, at level of antennae about equal to width of one eye; oc triangle yellow and oc ringed with black; ocp yellow; antenna all yellow, only third segment of arista black; gena yellow and pale yellow setulose, in profile about 1.1 height of eye; eye elongate-oval, longest axis almost horizontal; face very pale yellow, poorly sclerotised with thin and shallow median carina; mouthparts entirely yellow. Chaetotaxy: stronger setae pale brown to yellow, 3 usual orb, 1 vti and 1 vte, crossed pvt, postoculars in single row and longer postgenal setula.

Thorax: Entirely yellow and msn unstriped, only mtn and base of haltere dark brown. Chaetotaxy: setae pale brown, 2 hu (one very short), 1 psthu, 2 ntpl, 1 sa, 1 pa, 0+2 dc, acrs in 8 rows with prescutellar pair as long as anterior dc; 1 mspl and 1 stpl each with a few adjacent short white setulae.

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: Entirely yellow and pale yellow setulose; claws black except at base.

Abdomen: Yellow and slightly shining; setulae about 1/3 length of tg.

Postabdomen: ep with dark brown margin at base dorsally and more or less triangular dark spot at apex just above cercus; surs fused to ep, long broad and curved inwards; prg with about 10 comparatively strong setae, ph relatively simple appearing mostly as broad tubular structure.

Female.

Similar to male, but setae a little darker; tg pale brown over most of dorsal surface on basal segments, becoming less so on apical segments which are completely unspotted. Postabdomen (Fig. 4) with st 8 formed of two well sclerotised plates.

Length: ♂ 1.7 mm, wing 1.5 mm; ♀1.8 mm, wing 1.6 mm.

Variation: None noted.

Holotype: ♂ NAMIBIA: Lüderitz District: 8 km W Rosh Pinah, 27º59'28"S: 16º39'14"E, Malaise trap, 10– 26.viii.1998, A.H. Kirk-Spriggs and E. Marais, in glycerine tube (NMNW).

Paratypes: NAMIBIA: Lüderitz District: 3♀Spitzkop 111, 27º31'S: 16º42'E, pitfall traps, 8–19.viii.1990, E. Marais & C. Roberts, in alcohol (NMNW) ; 1♀Skorpion area, 27º49'S: 16º36'E, 9.viii.1997, beating/sweeping, A. Kirk-Spriggs & E. Marais (NMNW) ; 1♀Rooiberg, 27º38'S: 16º28'E, 22–24.ix.1997, Malaise trap, A. Kirk-Spriggs & E. Marais (NMNW) .