Key to male Megalestes

1 Color of cercus yellow (Fig. 3m); genital ligula with large middle lateral lobes (Fig. 5z) and obvious basal lateral lobes (Fig. 5 aa)............................................................................................. riccii

- Color of cercus black or dark brown; genital ligula without obvious basal lateral lobes, middle lateral lobes relatively small or absent.............................................................................................. 2

2 Paraproct without basal tooth, straight and strong, longer than 1/2 the length of the cercus (Fig. 6c)............... gyalsey

- Paraproct with basal tooth, never straight, seldom as long as 1/2 the cercus length.................................. 3

3 Horns present at the end of genital ligula (Fig. 5n)........................................................... 4

- Horns absent at the end of genital ligula, or only having lateral lobes............................................ 7

4 Distinct inner lateral tooth present at the middle of cercus (Fig. 3h), paraproct almost spherical (Figs. 4h; 6e)........ major

- No lateral tooth at middle of cercus, apex of paraproct produced, not spherical..................................... 5

5 Paraproct apex truncate, extended transversely, serrated with some hairs, a brushlike appearance; basal tooth large with end pointed (Figs. 4g; 6d); end of the genital ligula narrow, with the margin rounded (Fig. 5t)...................... kurahashii

- Paraproct apex pointed; end of the genital ligula broad with the margin trapezoidal................................. 6

6 Basal tooth of paraproct robust, longer than 1/2 the entire length of paraproct, with end pointed forward (Figs. 4b; 6l); genital ligula with obvious terminal lateral lobes (Fig. 5s)........................................................ irma

- Basal tooth of paraproct very small, shorter than 1/3 the entire length of paraproct, with end pointed upward (Figs. 4a, 6a); genital ligula without terminal lateral lobes (Fig. 5a, a 1)................................................. australis

7 Dorsum of 10 th abdomen segment normal, not swelling................................................. lieftincki

- Dorsum of 10 th abdomen segment more or less swelling (Fig. 4d)............................................... 8

8 Paraproct short with apex obtuse, covered with long, dense hairs that entirely cloak the apex; basal tooth of paraproct strong with base bulged and apex very acute pointed upward or a little forward (this character varied to some degree, cf. Figs. 4k and l and 6i and j); end of genital ligula modestly broad, elongate, and concave like a spoon; modest middle lateral lobes present but no basal and terminal lobes (Fig. 5w and x)............................................................ micans

- Paraproct produced back-upward with apex pointed or a little blunt; basal tooth of paraproct conical; end of genital ligula not elongate like a spoon; terminal lateral lobe present but basal or middle lobes absent................................. 9

9 Apex of paraproct somewhat blunt with sparse hairs mainly on the tip (Fig. 4i and j); end of genital ligula horizontal, broad, margin truncated, with small terminal lateral lobes (Fig. 5u and v)............................................. haui

- Apex of paraproct pointed with sparse hairs mainly on the rear side; end of genital ligula not at horizontal level......... 10

10 Apex of the cercus extended; basal prominence long, cylindrical with the end foot-like (Figs. 3 c–d and 4c–d); basal tooth of paraproct long and strong, at least as long as the produced paraproct apex (Figs. 3c and d; 4c and d); end of genital ligula narrow, slightly spoon-like, with terminal lateral lobes divergent largely, up-curved at tips (Fig. 5o)...................... distans

- Apex of the cercus normal; basal prominence short, flat, somewhat rectangular; end of genital ligula not spoon-like...... 11

11 End of genital ligula broad, terminal lateral lobes very large and bent forward like wings (Fig. 5p).................. heros

- End of genital ligula narrow, terminal lateral lobes small and wrapping genital end tightly (Fig. 5q)............. omeiensis