Key to male adults of Zavreliella Kieffer (modified from Reiss, 1990)

1. Inferior volsella medially arched (Reiss, 1990; fig. 18)................................................. Z. brauni

1’. Inferior volsella otherwise.............................................................................. 2

2. Inferior volsella with basal conical lobe projected medially (Reiss, 1990; fig. 20)....................................3

2’. Inferior volsella without such lobe........................................................................5

3. Superior volsella without lateral lobe (Reiss, 1990; fig. 22 c, d).......................................... Z. molesta

3’. Superior volsella with lateral lobe........................................................................ 4

4. Superior volsella with slender and clavate lateral lobe (Reiss, 1990; fig. 20)................................ Z. furcata

4’. Superior volsella with wide and rounded lateral lobe.................................................... Z. lobata

5. Inferior volsella wide and shovel-shaped (Reiss, 1990; fig. 23)..................................................6

5’. Inferior volsella cylindrical, with apical part club-shaped......................................................7

6. Superior volsella pediform, anal point very short, not exceeding the inferior volsella (Reiss, 1990; fig. 23).......... Z. curta

6’. Superior volsella slender with clavate lateral lobe, anal point long almost of the same length as the inferior volsella (Reiss, 1990; fig. 24)..................................................................................... Z. lata

7. Median setae of anal tergite usually absent. Superior volsella conical, with acuminate apex and lateromedian patch of setae (Reiss, 1990; fig. 17).............................................................................. Z. levis

7’. Numerous anal tergite setae always present. Superior volsella otherwise, with or without lateral patch of setae........... 8

8. Inferior volsella apically simple (single-lobed) (Reiss, 1990; fig. 15).............................................9

8’. Inferior volsella apically split, lobes clearly visible in lateral view (Reiss, 1990; fig. 10)............................ 12

9. Superior volsella with lateral patch of setae. Inferior volsella cylindrical......................................... 10

9’. Superior volsella without lateral patch of setae. Inferior volsella otherwise........................................13

10. Anal point projecting anteriorly and dorsally from anal tergite. Superior volsella with a few (less than 4) scattered setae, without lateral lobe (Reiss, 1990; fig. 19)............................................................... Z. fittkaui

10’. Anal point projecting posteriorly from the margin limits of anal tergite. Superior volsella with 4-5 setae grouped laterally, sometimes in a shallow rounded lobe.................................................................... 11

11. Inferior volsella straight, with two apical setae twice as long and stout as remaining subapical setae. Superior volsella with lateral lobe (Reiss, 1990; fig. 25).................................................................. Z. longiseta

11’. Inferior volsella with curved apex, apical and subapical setae equal in length. Superior volsella without lateral lobe (Figs. 2 and 3)..................................................................................... Z. kambeba sp. n.

12. Anal point acuminate. Anal tergite with 16–21 median setae. Superior volsella digitiform. Inferior volsella thin, straight and slightly expanded distally (Reiss, 1990; fig. 15)........................................................ Z. acuta

12’. Anal point parallel sided, with blunt apex. Anal tergite with only 4–11 median setae. Superior volsella with tapered and slightly curved distal half. Inferior volsella with very thin base and club-shaped apex (Reiss, 1990; fig. 16)................ Z. junki

13. Superior volsella with three median setae and very long subapical seta (about twice as long as median ones) (Reiss, 1990; fig. 14)........................................................................................ Z. cranstoni

13’. Superior volsella mostly with only two median equally short setae (exceptionally one or three setae present)............ 14

14. Superior volsella with hemispherical lateral lobe and sharp-pointed conical distal part. Gonostylus thin, not widened at midlength. Cephalic tubercle present (Reiss, 1990; fig. 8)............................................... Z. verrucosa

14’. Superior volsella with shallow indicated lateral lobe and thin digitiform distal part. Gonostylus large, widened at midlength. Cephalic tubercle absent (Reiss, 1990; figs. 9–12)................................................. Z. marmorata