Provisional Key to Males of Nemoura from Vietnam and Thailand

1 Paraprocts in ventral aspect bearing a long, slender, acute lobe projecting to tips of cerci (Figs. 6, 15); cerci usually simple.…………………….. 2

1’ Paraprocts without projecting slender lobe (Figs. 3, 11); cerci modified with truncate or bilobed apices (Figs. 1, 11) ………………………..……… 4

2 Paraproct outer lobe club-shaped in lateral aspect; epiproct apex serrate in lateral aspect (Fig. 5) …………………………………………….… clavaloba

2’ Paraproct outer lobe acute in lateral aspect (Fig. 14); epiproct apex not serrate (Figs. 13-14) ……. 3

3 Epiproct somewhat quadrangular in dorsal aspect (Fig. 24); tergum 10 without spiny armature ……………………………………………… tenuiloba

3’ Epiproct margins convergent in apical half (Fig. 13); tergum 10 bearing sensilla basiconica and a cluster of spines near epiproct (Fig. 13) ……………………..……………………. raptoraloba

4 Cercal apices truncate in dorsal aspect (Fig. 1); tergum 9 with a mesal row of long setae .. apicalis

4’ Cercal apices variable but not truncate; tergum 9 without mesal row of long setae ……………….. 5

5 Posterior margin of tergum 9 bearing a pair of spiny lobes (Fig. 9) …….……….…… neospiniloba

5’ Posterior margin of tergum 9 without spiny lobes (Fig. 7) ……………………………..……………… 6

6 Cerci in dorsal aspect with a small knob near midlength on outer margin and a stout seta on inner margin (Fig. 7) ……………………. magniseta

6’ Cerci without small knob or stout seta …………. 7

7 Posterior margin of tergum 9 bearing patches of sensilla basiconica (Fig. 17); lateral aspect of cerci bearing a short, thick, relatively straight spine arising from midlength (Fig. 18) ………. spinacerca

7’ Posterior margin of tergum 9 without sensilla basiconica (Fig. 21); lateral aspect of cerci bearing a long, anteroventrally curved spine arising from the posterior cercal margin (Fig. 22) …. stylocerca