Hymenopteran family Vespidae, with more than 5,000 species worldwide, is divided into six monophyletic subfamilies (Pickett and Carpenter, 2010). Four of the six vespid subfamilies are distributed in the Oriental region including Vietnam. They are the solitary wasp subfamily Eumeninae (potter wasps), the largest subfamily in the Vespidae, and the three social wasp subfamilies, that is, Stenogastrinae (hover wasps), Polistinae (paper wasps), and Vespinae (hornets and yellow-jackets). There are about 1,100 social wasp species in the world fauna and the highest number of species is recorded in Neotropics. Social wasps play important roles in ecosystem: they are beneficial in agriculture and forestry and can be used as biological pest control agents, and potentially useful for bio-monitoring of change in environments as they are very susceptible to pesticides and rapid environmental changes, and more than that, they are important model organisms for the study of the evolution of social behaviour.  

Social wasps make their nests underground, hanging on tree branches, on the roof of the house… The nests are made from bark, plant fiber, or mud mixed with saliva. The nests are with an envelope or without, with several combs or with only one comb. Their colonial life has members of the same generation using the same nest and cooperating in brood care, reproductive division of labor (worker caste cares for the young of the reproductive caste), and there is an overlap in generations so that offspring assist parents (workers who help to rear the offspring of queens, caste system, division of labor, and communication).

Vietnam is expected to harbor a very diverse biota, not only because it spreads widely from subtropics or warm-temperate in the north to tropics in the south, but also because the northern part is on the eastern slope of Himalaya, one of the centers of biological diversity. This should also be the case for the vespid wasps, and especially the northern part of Vietnam is supposed to be one of the areas with the richest vespid faunas in the Oriental region. This book presents of our research on Vietnamese social wasps from 2004 to 2019, including all results obtained from our publications up to date. The investigation has been done at a large number of collected localities in 52 provinces throughout Vietnam, with 92 species have been recorded. Keys for identification of genera in Asia and species occurring in Vietnam together with color and SEM illustrations are provided. For each species, its photographs, recorded distribution, and some available biological information are presented. Moreover, the distribution pattern of Vietnamese social wasps is also discussed.