The newly discovered larva and previously unassociated pupa of Xiaomyia Sæther & Wang, a distinctive outlier in the subfamily Chironomidae, allows description, illustration and comparison with its proposed closest relative, Shangomyia Sæther & Wang. A previously described bizarre pupal exuviae, ‘Taxon 2’ sensu Coffman et al. (1988) from south India belongs to Xiaomyia. Molecular data from other sources allows review of the phylogeny and an estimate of the evolutionary tempo. As proposed for the pupa, and independently from adult male morphology, molecular data locate the two genera in a clade that is the sister group to the three other named tribes combined, warranting tribal status within the subfamily Chironominae. Expanded and revised diagnoses for larva, pupa, and adults of Xiaomyiini new tribeare provided. A novel ribbed and spinulose plate-like lobe associated with the ventral larval maxilla in Shangomyia and Xiaomyia is a major synapomorphy for the tribe.

The potter wasp genus Pareumenes de Saussure, 1855, is represented in Vietnam by two species, Pareumenes quadrispinosus acutus Liu, 1941 of the subgenus Pareumenes, and a new species, Pareumenes caoduong, belonging to the subgenus Nortonia. The new species is described and figured. A key to all known taxa of this genus from the Oriental region is also provided.

The nomenclature of the Indo-West Pacific spider crab genus Schizophrys White, 1848 (Majidae) is clarified, including the authorship, date of publication, and type species designation. The nomenclature of the genus is reviewed and species with confused taxonomic identities are discussed. The status of one poorly known species supposedly from the Mediterranean Sea, Schizophrys dichotomus Desmarest, 1823, is clarified. A type specimen of Mithrax asper H. Milne Edwards, 1831, one of the most widely reported Schizophrys species, was rediscovered and is herein designated as the lectotype. Inachus bifidus Marion de Procé, 1822 is here determined to be a synonym of Mithrax asper H. Milne Edwards, 1831, and we invoke Article 23.9.1.1 of the current zoological code to reverse the precedence of the names to conserve Mithrax asper, which is in current and prevailing usage.

The nomenclature of the Indo-West Pacific spider crab genus Schizophrys White, 1848 (Majidae) is clarified, including the authorship, date of publication, and type species designation. The nomenclature of the genus is reviewed and species with confused taxonomic identities are discussed. The status of one poorly known species supposedly from the Mediterranean Sea, Schizophrys dichotomus Desmarest, 1823, is clarified. A type specimen of Mithrax asper H. Milne Edwards, 1831, one of the most widely reported Schizophrys species, was rediscovered and is herein designated as the lectotype. Inachusbifidus Marion de Procé, 1822 is here determined to be a synonym of Mithraxasper H. Milne Edwards, 1831, and we invoke Article 23.9.1.1 of the current zoological code to reverse the precedence of the names to conserve Mithrax asper, which is in current and prevailing usage.