Abstract
The chromosomes of 21 species of Vespidae (consisting of 9 polistines and 12 vespines) were compared using an air-drying technique. The haploid number of the Polistinae ranged broadly (n=14, 22, 23, 26, 30, 31, and 34), while it was either n=25 or n=26 in the Vespinae. There were no karyological homologies (in terms of marker chromosomes) between these two subfamilies. Some phylogenetic relationships of social wasps were discussed, based on the karyological literature now available (32 species). We suggested that the three genera of Vespinae (Dolichovespula, Vespa, and Vespula) would have differentiated in two different ways from a common ancestor having 27 acrocentrics (n=27) by tandem fusion (the first genus with n=26) and by two centric fusions (the latter two genera with n=25). In the genus Polistes, the 5 subgenera (Fuscopolistes, Aphanilopterus, Megapolistes, Polistella, and Polistes) would have evolved independently toward increasing chromosome numbers since they started to separate from their ancestor having n=9-14.
