„ 2006 Zoological Society of Japan ZOOLOGICAL SCIENCE 23: 95–104 (2006) Vespidae of Viet Nam (Insecta: Hymenoptera) 2. Taxonomic Notes on Vespinae Lien T. P. Nguyen 1 , Fuki Saito 2 , Jun-ichi Kojima 2 * and James M. Carpenter 3 1 Insect Ecology Department, Institute of Ecology and Biological Resources, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet Road, Nghia Do, Cau Giay, Ha Noi, Viet Nam 2 Natural History Laboratory, Faculty of Science, Ibaraki University, Mito 310-8512, Japan 3 Division of Invertebrate Zoology, American Museum of Natural History, Central Park West at 79th Street, New York, New York 10024, USA The taxonomy of the Vietnamese species of the social wasp subfamily Vespinae is revised. Vespa auraria Smith, 1852, is synonymized under V. velutina Lepeletier, 1836. Vespula koreensis (Radosz- kowski, 1887) is recorded as new for Viet Nam, and its color characters are described. A key to vespine species of Viet Nam based on morphological characters is provided. Key words: Hymenoptera, Vespidae, Vespinae, Viet Nam, identification key, new distribution record INTRODUCTION While the taxonomy and distribution of social wasps in Southeast Asia have, in general, been well studied (van der Vecht, 1941, 1957, 1962, 1966; Das and Gupta, 1989; Kojima et al., 2005; Saito and Kojima, 2005; Saito et al., 2005), until Nguyen and Carpenter (2002) the social wasp fauna of Viet Nam was very poorly known despite the expected species richness. That paper treated the Ves- pinae, one of the three social wasp subfamilies, and recorded 15 species of three genera ( Provespa Ashmead, 1903, Vespa Linnaeus, 1758, and Vespula Thomson, 1869) and provided keys to vespine species occurring in Viet Nam, primarily following the treatment by Archer (1989). In his keys to Vespa species, Archer (1989) treated as species the following three taxa that van der Vecht (1957, 1959) regarded as subspecies: Vespa auraria Smith, 1852, as distinct from V. velutina Lepeletier, 1836; V. ducalis Smith, 1852, separated from V. tropica (Linnaeus, 1758); and V. soror du Buysson, 1905, as a distinct species from V. mandarinia Smith, 1852. The reasoning for these treat- ments, however, was not mentioned until Archer (1991a: 163) stated “... V. velutina auraria and V. velutina nigrithorax du Buysson, 1905 are sympatric in north-eastern India ... but remain distinct color forms so V. velutina auraria may be considered as having reached specific rank”, “... V. manda- rinia soror du Buysson, 1905 is sympatric with V. mandarinia magnifica [Smith, 1852] ... but retains a distinct color form so it can be given specific rank...”, and for V. ducalis , he mentioned “ ... V. tropica ducalis Smith, 1852 and V. tropica pseudosoror van der Vecht, 1959 are sympatric with V. trop- ica haematodes Bequaert, 1936 and V. tropica leefmansi van der Vecht, 1957 ...”. All these species were included in Nguyen and Carpenter (2002), with V. auraria and V. man- darinia being records new to Viet Nam. In the published series of his study on the taxonomy and biology of Vespa , Archer (1991b, 1992, 1994, 1995, 1997) synonymized subspecies of V. affinis (Linnaeus, 1764), V. crabro Linnaeus, 1758, V. ducalis , V. mandarinia , V. tropica , and V. velutina by proposing informal names for local color forms instead of formal subspecies names. Carpenter and Kojima (1997) accepted Archer’s work as a basis for extend- ing the synonymy to the remaining subspecies and sank all subspecies in the Vespinae under the nominate species, although without being aware of that paper Archer (1998, 1999) returned to use of formal subspecies names in V. ori- entalis Linnaeus, 1771 and V. luctuosa de Saussure, 1854. Archer (1991b, 1994, 1995) provided the characters to dif- ferentiate between V. tropica and V. ducalis , between V. auraria and V. velutina , and between V. mandarinia and V. soror - all are color characters. At the same time, he recog- nized two, eight, three, and 11 color forms respectively in V. ducalis , V. tropica , V. mandarinia , and V. velutina . Archer’s treatments may have introduced confusion into the taxon- omy of these six “species”. In each case, one of the two sympatric color forms was assigned a priori to one of the species in a pair concerned, without any explanation. By this logic, the alternative taxonomic conclusions are equally pos- sible. For example, in the case of V. velutina and V. auraria , Archer a priori assigned nigrithorax to V. velutina and con- cluded auraria was a distinct species; however, auraria could equally well be a color form of V. velutina and nigritho- rax a distinct species. Considering the fact that Vespa spe- cies often represent considerable local color variation, taxo- nomic conclusions such as Archer made should be based * Corresponding author. Phone: +81-29-228-8377; Fax : +81-29-228-8403; E-mail: jkrte@mx.ibaraki.ac.jp doi:10.2108/zsj.23.95