Key to the genera of Argentinean Proconiini (modified from Young 1968)

1 Forewing at rest exposing meron of hindleg................................................................ 2

- Forewing at rest not exposing meron of hindleg............................................................. 11

2 Pronotum and forewings coarsely pitted; pronotum with posterior margin convex and extending posteriorly to or nearly to transverse impression of scutellum........................................................ Tretogonia Melichar

- Without above combination of characters.................................................................. 3

3 Species with dense pubescence; clypeus forms an approximately right angle with longitudinal axis of body; abdomen distinctly broad and short.......................................................................... Teletusa Distant

- Without above combination of characters.................................................................. 4

4 Apex of head curved slightly dorsally and angulate at transition from crown to face; male pygofer very long, exceeding wing apices with wings at rest position; female abdominal sternite VII with posterior margin deeply emarginate, and first ovipositor valvulae with apex truncate bearing acute median projection [see Figs. 1, 2, 21 and 22 in Dellapé (2015)]... Acrogonia Stål

- Without above combination of characters.................................................................. 5

5 Metepimeron with shelf-like projection upon which forewing rests when in rest position............................ 6

- Metepimeron without projection or with very weak one..................................................... 10

6 Abdomen not constricted basally........................................................................ 7

- Abdomen constricted basally........................................................................... 8

7 Forewings hyaline or translucent; male pygofer processes when present not arising on ventral margin before apex (exception: E. speculifera (Walker)); female second valvulae broadened beyond basal curvature, and apex obtuse [see Fig. 66 in Dellapé (2015)]................................................................................. Egidemia China

- Forewings opaque; male pygofer processes arising on ventral margin before apex; female second valvulae rectilinear beyond basal curvature, and apex rounded [see Figs. 72 to 75 in Dellapé (2015)]........................... Oncometopia Stål

8 Crown of head with median apical carina, pronotum with distinct transverse sulcus parallel to anterior margin, delimiting a collar like anterior portion.................................................................. Propetes Walker (*)

- Without above combination of characters.................................................................. 9

9 Proepimeron with ventral marginal area depressed................................................... Phera Stål

- Proepimeron with ventral marginal area not depressed.......................................... Homalodisca Stål

10 Clypeus strongly convex; male plates extremely short, not extending posteriorly to midlength of ventral pygofer margin; female abdominal sternite VII with median projection on posterior margin [see Figs. 8 to 11 in Dellapé (2015)]................................................................................................... Molomea China

- Clypeus convex; male plates longer, extending posteriorly beyond midlength of ventral pygofer margin; female abdominal sternite VII with posterior margin from concave medially to nearly transversely rectilinear [see Figs. 17 to 19 in Dellapé (2015)]............................................................................... Tapajosa Melichar

11 Species usually white; apex of head with very short, blunt projection or circular scar (in frontal view); proepimeron with posteriorly directed digitate process from hind margin................................... Diestostemma Amyot & Serville

- Without above combination of characters................................................................. 12

12 Male pygofer with processes; female abdominal sternite VII with posterior margin emarginate with a slight median process within emargination, and second valvulae with more than 30 teeth on dorsal margin of blade (Figs. 1 to 7)............. 13

- Male pygofer without processes; female abdominal sternite VII not as above and second valvulae with 20 to 30 teeth on dorsal margin of blade..................................................................................... 15

13 Male pygofer with two pairs of processes each resembling clump of setae; female first valvulae with apex acute and slightly curved downward (Fig. 18)................................................................ Cicciana Metcalf

- Male pygofer with processes arising on dorsal margin, extending ventrally; female first valvulae with apex obtuse with dorsal margin slightly concave (Figs. 13 to 17 and 19)............................................................ 14

14 Aedeagus with scoop-shaped process near apex; female first valvulae with dorsal sculptured area formed mostly by scale like processes, and ventral sculptured area formed mostly by linear processes (Figs. 13 to 17); second valvulae with triangular teeth on dorsal margin of blade (Figs. 25 to 29)............................................ Aulacizes Amyot & Serville

- Aedeagus appearing inflated in caudoventral view; female first valvulae with dorsal and ventral sculptured area formed mostly by linear processes (Fig. 19); second valvulae with subsquare teeth on dorsal margin of blade (Fig. 31).................................................................................................... Pseudometopia Schmidt

15 Hindwings with vein R2+3 entire........................................................................ 16

- Hindwings with vein R2+3 interrupted.................................................................... 17

16 Body length more than 12 mm; crown with anterior margin broadly rounded in dorsal view, and apex carinate; aedeagus slen- der elongate and arched gradually dorsally, with pair of apical processes; posterior margin of female abdominal sternite VII with median triangular projection (Fig. 8)..................................................... Stictoscarta Stål

- Body length less than 12 mm; crown with anterior margin rounded without carina; aedeagus very short, U-shaped in lateral view, with pair of long slender basal processes extending posteriorly beyond apex of shaft; posterior margin of female abdominal sternite VII with shallow medial concavity [see Fig. 3 in Dellapé (2015)]........................ Anacuerna Young

17 Body not depressed; crown of head rounded; aedeagus with pair of processes arising at base, finely hairy in apical half; paraphyses absent; female abdominal sternite VII with posterior margin deeply emarginate medially, and second valvulae with subrectangular teeth on dorsal margin of blade [see Figs. 4 and 44 in Dellapé (2015)]................... Dechacona Young

- Body depressed dorsoventrally; crown of head strongly inflated; aedeagus without processes; paraphyses present; female abdominal sternite VII with posterior margin transverse or sinuous, and second valvulae with subtriangular teeth on dorsal margin of blade...................................................................... Ochrostacta Stål (**)