Key to species of Brachygasterina Macquart

(males are unknown for B. andina, B. fulvohumeralis, B. stuebeli and B. valdiviensis)

1. General colour metallic violet­blue; humeral callus and prothoracic spiracle orangeyellow, notopleura dull reddish­yellow; calypters dark brown (Chile)........................... .................................................................................. B. fulvohumeralis (Malloch, 1922)

­ General colour subshining dark metallic violet­blue, including humeral callus and notopleura; prothoracic spiracle black; calypters brownish with dark brown margins 2

2. Base of R4+5 on wing with cilia on both surfaces; hind tibia on anterodorsal and anteroventral surfaces with at least 4 and 3 setae respectively; prealar seta absent (male) or weak (female), shorter than anterior notopleural seta; sternite 1 setulose. Male: hind femur on posteroventral surface bare on apical half and with longer setae on basal half. Female: fore tibia on anterodorsal surface with 4 short setae on apical half (Chile, Argentina) .............................................................. B. major Malloch, 1934

­ Base of R4+5 on wing bare on both surfaces; hind tibia on anterodorsal and anteroventral surfaces with at most 3 setae (frequently 2); prealar seta subequal to or much longer than anterior notopleural seta; sternite 1 bare. Male: hind femur not as above. 3

3. Eye with long and dense hairs (Fig. 3); facial ridge with setulae reaching almost to level of aristal insertion (Fig. 8); wing with crossvein dm­cu very sinuous, about 1/3 of the distance to r­m; vein M slightly upcurved toward R4+5 (Ecuador, Colombia)........... ................................................................................................. B. stuebeli (Röder, 1886)

­ Eye with short and sparse hairs (Figs 1, 4, 5); facial ridge bare or at most with a few setulae reaching only to mid­level of first flagellomere; wing with crossvein dm­cu less sinuous, at most 1/5 of the distance to r­m; vein M straight, parallel with R4+5 .... 4

4. Facial ridge bare (Fig. 6). Male unknown. Female: parafacial narrow, in lateral view at narrowest point 0.2 of width of first flagellomere (Fig. 6) (Ecuador) ............................ ............................................................................................................ B. andina sp. nov.

­ Facial ridge with a few setulae, reaching only to mid­level of first flagellomere (Figs 9, 10). Female: parafacial very narrow, in lateral view at narrowest point less than 0.2 of width of first flagellomere (Figs 9, 10) ................................................................... 5

5. Male: hind femur on posteroventral surface with long setae on apical half, shorter on basal half. Female: fore tibia on dorsal surface without a preapical seta; length of sternite 6 about half the length of the segment; 3 spermathecae (Chile, Argentina) ........... ................................................................................... B. violaceiventris Macquart, 1851

­ Male unknown. Female: fore tibia on dorsal surface with a preapical seta; length of sternite 6 about 1/3 the length of the segment; 2 spermathecae (Chile) ......................... ...................................................................... B. valdiviensis (Pamplona & Couri, 2000)