Key to males of Prolachesilla

(Modified from Mockford & Sullivan 1986)

1. Body color predominantly pale creamy white with some dark brown markings............ P. pallida Mockford & Sullivan

- Body color predominantly pale tawny brown............................................................... 2

2. Micropterous, wings minute, not reaching base of abdomen. Species of ground litter...... P. terricola Mockford & Sullivan

- Generally macropterous, occasionally brachypterous. Species of tree and shrub foliage and dead maguey stalks and leaves. 3

3. Hairs on margin of forewing about same length and frequency as hairs on vein............. P. pilosa Mockford & Sullivan

- Hairs on margin of forewing much smaller and sparser than hairs on veins....................................... 4

4. Aedeagal arch terminating in a wide hood (Fig. 4).............................................. P. boliviana n. sp.

- Aedeagal arch not terminating in a wide hood (Figs 9, 19).................................................... 5

5. Elongate postero-lateral pair of setae of epiproct truncated and slightly expanded at tips. Aedeagus terminating as a knob (see Figs 83 and 84 in Mockford & Sullivan 1986)................................... P. callangana Mockford & Sullivan

- Elongate postero-lateral pair of setae of epiproct acuminate at tip. Aedeagus terminating as a slender process (Fig. 19).... 6

6. Clunial shelf over epiproct distinctly bilobed (Figs 3, 8, 18)................................................... 7

- Clunial shelf over epiproct not bilobed, but slightly emarginated in middle in one species (see Figs 69 and 74 in Mockford & Sullivan 1986)...................................................................................... 11

7. Lobes of clunial shelf over epiproct with margins smooth or with a few very low, rounded raised areas (Figs 8, 18)....... 8

- Lobes of clunial shelf with margins bearing irregular knobs and finger-like projections (Fig. 23)..................... 10

8. External parameres with straight apex, without spines.............................. P. mexicana Mockford & Sullivan

- External parameres curved to outside in the apex, this with spines (Fig. 9, 19)..................................... 9

9. Endophallus with two separated groups of denticles (Fig. 9)...................................... P. casasolai n. sp.

- Endophallus only with one group of denticles (Fig. 19)...................................... P. casasolaoides n. sp.

10. Male paraprocts with marginal spines. Posterior border of hypandrium with three lobes. Lobes of clunial shelf wide (Figs 23, 25)................................................................................... P. oaxacana n. sp.

- Male paraprocts without spines. Posterior border of hypandrium rounded, without lobes. Lobes of clunial shelf narrow (see Figs 62 and 64 in Mockford & Sullivan 1986).................................... .. P. poblana Mockford & Sullivan

11. Clunial shelf over epiproct angular on sides, its entire margin irregularly roughened with small knobs and a few pointed pro- cesses (see Fig. 69 in Mockford & Sullivan 1986).................................... P. ticana Mockford & Sullivan

- Clunial shelf rounded on sides, its margin nearly smooth, slightly wavy..........................................12

12. Clunial shelf over base of male epiproct broad, covering ca. two-thirds the width of the epiproctal base (see Fig. 74 in Mock- ford & Sullivan 1986)........................................................ P. mediana Mockford & Sullivan

- Clunial shelf over base of male epiproct narrower, covering slightly less than half the width of the epiproctal base (see Fig. 101 in Mockford & Sullivan 1986)............................................... P. panamense Mockford & Sullivan