Siphlonurus dongxi Li & Tong, sp. nov. from Shangri-La City, Yunnan Province, China, is described based on egg, nymph, and winged stages. The new species is closely related to S. davidi (Navás, 1932), and can be distinguished by the colour of the imago, the forking point of MP, the penis, posterolateral spines of tergum IX of imagoes, and first abdominal terga nymph, as well as the structure of the egg. The new species and S. davidi have the same morphological and structural characteristics, such as the long cubital area with many intercalaries, cross veins between C, Sc, RA, and RSa1 surrounded with distinct pigments, the strong curvature of vein CuP in the forewing, the broad expansion of the hindwing, the membranous penis lobes fused without teeth, supporting the proposition of a new species complex, the Siphlonurus davidi group. The structures of the penis and the egg of the new species could help understand the origin and evolution of the genus Siphlonurus.

Two new species of Nigrobaetis Kazlauskas (in Novikova & Kluge), 1987 are described from Southwest China: Nigrobaetis bilongus sp. nov. based on larval and imaginal materials which are reared from larvae; Nigrobaetis trialbus sp. nov. based on larval stage.

Notacanthella jinwu Li & Jacobus, sp. nov. is described based on egg, nymph, and winged stages from Dali Bai Autonomous Prefecture, Yunnan Province, China. The nymph of the new species is closely related to N. commodema (Allen, 1971), whose nymphs share a similar tuberculation of head, pronotum, and mesonotum. However, the nymph of our new species can be distinguished based on the structures of male sternum IX and abdominal tergal tubercles. In addition, the new species is distributed in subtropical high-altitude areas. The description of the male imago of the new species is the first certain one for the genus Notacanthella. Data associated with our new species allow for expanded discussion and diagnosis of Notacanthella and closely related genera. An identification key for nymphs of these groups is provided.

Some new information on the genus Lethe Hübner, 1819 from Nujiang (upper Salween) valley, western Yunnan is provided. Lethe laodamia Leech, 1891 is recorded from this area for the first time, which turned out to be a new subspecies and described herein, viz. L. laodamia murasameae S.-Y. Huang & Lang ssp. n. Little known Lethe liae Huang, 2002 is rediscovered, and its relationship with its allied taxa is discussed. Adults and male genitalia of the aforementioned and related taxa are illustrated.