Key to females of the described Neotropical species of Gonatocerus (Gonatocerus)

[ Gonatocerus (Gonatocerus) aequatorianus (Ogloblin) not included because it is known only from a male]

1 Forewing with a narrow brown band extending from marginal or stigmal veins to posterior margin of wing ........... 2

- Forewing without band behind marginal or stigmal veins............................................................................................ 3

2(1) Antenna with mps on F7 and F8 only and clava incised at apex (Fig. 12); forewing with brown band mostly behind stigmal vein (Fig. 14) ............................................................................... G. (Gonatocerus) appendiculatus (Ogloblin)

- Antenna with mps at least on F4–F8 and clava not incised at apex (Fig. 54); forewing with brown band mostly behind marginal vein (Fig. 56) ....................................................................... G. (Gonatocerus) stenopterus (Ogloblin)

3(1) Pronotum with lobes widely separated from each other; ovipositor exserted beyond apex of gaster by at least 0.5x own length (Fig. 49) ......................................................................................... G. (Gonatocerus) perforator (Ogloblin)

- Pronotum with lobes abutting medially; ovipositor exserted beyond apex of gaster by at most 0.4x own length....... 4

4(3) F5 without mps.............................................................................................................................................................. 5

- F5 with 1 or 2 mps ........................................................................................................................................................ 7

5(4) F6 without mps; forewing disc almost hyaline, at most with faint, uniform brownish tinge ....................................... 6

- F6 usually with mps; forewing disc notably infumate with brown throughout ............................................................. ..................................................................................................................... G. (Gonatocerus) excisus (Ogloblin) (part)

6(5) F1 strongly incised dorsoapically (Fig. 22); forewing at most 4.2x as long as wide...................................................... ............................................................................................................................. G. (Gonatocerus) californicus Girault

- F1 not incised (although curved) dorsoapically (Fig. 19); forewing at least 4.9x as long as wide ................................ ....................................................................................................................... G. (Gonatocerus) bonaerensis (Ogloblin)

7(4) Ovipositor short (ovipositor length: mesotibia length ratio at most 1.1:1), not exserted beyond gastral apex ........... 8

- Ovipositor long (ovipositor length: mesotibia length ratio at least 1.7:1), exserted beyond gastral apex by at least 0.14x own length........................................................................................................................................................... 9

8(7)F3 with 2 mps .................................................................................................. G. (Gonatocerus) granulosus (Ogloblin)

- F3 without mps ........................................................................................... G. (Gonatocerus) excisus (Ogloblin) (part)

9(7) F4 with 2 mps; ovipositor exserted beyond gastral apex by about 0.4x own length (Fig. 45) ...................................... .............................................................................................................................. G. (Gonatocerus) mexicanus Perkins

- F4 without mps or sometimes with 1 mps; ovipositor exserted beyond gastral apex by at most 0.3x own length .... 10

10(9)F6 with 1 or 2 mps .....................................................................................................................................................11

- F6 without mps............................................................................................................................................................12

11(10)Forewing with a distinct round or oval brown spot with diffuse margins in apical 0.3 of wing (Fig. 42) ................. .................................................................................................................................. G. (Gonatocerus) koebelei Perkins

- Forewing slightly infumate throughout, without a brown spot (Fig. 61).... G. (Gonatocerus) urocerus Ogloblin (part)

12(10)Forewing usually with a more or less distinct (sometimes faint or absent) round or oval brown spot in apical 0.3 of wing; ovipositor exserted beyond gastral apex by at most 0.2x own length .............................................................. 13

- Forewing slightly infumate throughout, without a brown spot (Fig. 61); ovipositor exserted beyond gastral apex by about 0.3x own length ................................................................................. G. (Gonatocerus) urocerus Ogloblin (part)

13(12)Forewing at most 4.0x as long as wide; longest marginal seta about one third (0.31–0.36x) maximum wing width ...................................................................................................................................... G. (Gonatocerus) rivalis Girault

- Forewing at least 4.1x as long as wide; longest marginal seta a little less than half (0.44–0.47x) maximum wing width ..................................................................................................................... G. (Gonatocerus) antillensis Dozier