Three new species of Helicopsyche from Vietnam (Trichoptera : Helicopsychidae)

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.