Key to separate Micrathyria species from México

(Adapted and modified from Ris 1911)

1 Two cells between posterior angle of the triangle and midrib of anal loop......................................... 2

- One cell between posterior angle of triangle and midrib of anal loop............................................. 8

2 Anal loop with toe poorly developed, composed of 3–4 cells beyond ankle.................................. dictynna

- Anal loop with a well developed toe, composed of 5 or more cells beyond ankle................................... 3

3 Hamular processes very prominent, anteriorly directed and greatly exceeding the height of anterior lamina; HW with no single cell between MA and MP, series starting with two row cells.................................................... 4

- Hamular processes normal and not directed anteriorly; HW with at least one or two full width between MA and MP....... 5

4 With three unbranched green stripes at sides of pterothorax; genital lobe shorter at the most 0.5 the height of posterior rami of the hamuli...................................................................................... didyma

- With two unbranched green stripes at sides of pterothorax; genital lobe larger almost 0.75 the height of posterior rami of the hamuli................................................................................. paulsoni sp. nov.

5 Fore wing triangle crossed; hind wing with three cell rows between AA and wing margin.......................... atra

- Fore wing triangle free; with two rows in this area........................................................... 6

6 S3–6 with pale lateral spots; on S5–6 they reach almost the basal half of the segment, metepimeron pale without dark stripes.............................................................................................. hagenii

- S3–4 without pale lateral bands, S5 with a basal point, S6 totally dark, metepimeron crossed by a dark stripe............. 7

7 In dorsal view apices of cerci converging............................................................. ocellata

- In dorsal view apices of cerci divergent............................................................. dissocians

8 Fore wing triangle with 2–3 cells......................................................................... 9

- Fore wing triangle free............................................................................. debilis

9 Fore wing triangle 3-celled, hind wing 26 mm or more................................................ schumanni

- Fore wing triangle 2-celled, hind wing 24 mm or less................................................... aequalis