The Vietnamese fauna of bees in the Anthidiellum Cockerell (Megachilinae, Anthidiini) is reviewed. Seven species are recognized, representing two subgenera. Five new species are described and figured as: Anthidiellum (Clypanthidium) nahang Tran, Engel & Nguyen, sp. nov., A. (Pycnanthidium) ayun Tran, Engel & Nguyen, sp. nov., A. (P.) chumomray Tran, Engel & Nguyen, sp. nov., A. (P.) flavaxilla Tran, Engel & Nguyen, sp. nov., and A. (P.) cornu Tran, Engel & Nguyen, sp. nov. from the northern and central highlands of Vietnam. Two previously described species are newly recorded for the fauna: A. (P.) carinatum (Wu) and A. (P.) coronum (Wu), with the male of the latter species described and illustrated for the first time. An identification key is provided for all species of Anthidiellum occurring in Vietnam.

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Twenty seven species of the subgenus Polistella Ashmead, 1904 are recorded from Vietnam. Polistes chuyangsin Nguyen Nguyen sp. nov. and its nest are described and figured. A pictorial key to Vietnamese species of the subgenus is provided.

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Notes on the paper wasp of the genus Polistes, Polistes delhiensis Das and Gupta, 1989 (Hymenoptera: Vespidae: Polistinae) from Vietnam are presented. The species has two color forms of the clypeus: brightly colored specimens were collected in the southern part of the range and darker colored specimens were collected in the northern part. Based on morphological and DNA data analysis, it is confirmed that both color forms belong to Polistes delhiensis. The male of this species is described for the first time and its fully-developed nest is also described.