Three new species of Helicopsyche are described from Vietnam: Helicopsyche
khemoiensis NEW SPECIES, Helicopsyche azunensis NEW SPECIES and Helicopsych
e dacklestensis NEW SPECIES. Helicopsyche khemoiensis is most closely relat
ed to H. coreana Mey, the two species comprising the subgenus Galeopsyche.
Helicopsyche khemoiensis is distinguished from H. coreana by the shape of t
he gonocoxite and armature of tergite X. Immature stages of H. khemoiensis
are described. Helicopsyche azunensis and H. dacklestensis, subgenus Helico
psyche, are most closely related to Helicopsyche chrysothoe (Schmid), H. xe
nothoe (Schmid) and other species characterized by four-segmented maxillary
palps, absence of mesoscutal warts and distally hooked gonocoxal secondary
branch. Helicopsyche azunensis and H. dacklestensis are distinguished from
other species in that group by the presence on the phallus of large endoth
ecal sclerites.