Key to species of the Polistes stigma group from continental Southeast Asia The characters used are applicable to both sexes unless the sex is specified. 1. Body with coarse punctures. Propodeum with strong transverse striae. Body with yellow markings reduced, clypeus entirely or largely brown or black........................................................................2 − Body with weaker punctures. Propodeum with weaker transverse striae. Body with extensive yellow or reddish marks.......................4 2. Female: Flagellomere I 2.8 times as long as its maximum width. Frons and mesoscutum with less coarse punctures. Body mainly brown.................... Polistes brunus, new species − Female: Flagellomere I 3 times or slightly greater than 3 times as long as its maximum width. Frons and mesoscutum with coarse punctures. Body mainly black ..................................................................3 3. Female: Inner eye margins in frontal view 1.1 times further apart from each other at vertex than at clypeus; clypeus in frontal view as wide as high; gena in lateral view narrower than eye. Dorsal metapleuron with short and weak striae. Wing transparent except dark spots at apical margin of fore wings. Body nearly entirely black....... Polistes tenebris, new species − Female: Inner eye margins in frontal view about as far apart from each other at clypeus as at vertex; clypeus in frontal view slightly wider than high; gena in lateral view slightly wider than eye. Dorsal metapleuron with longer and thicker striae. Wing light yellow except dark spots at apical margin of fore wings. Body with extensive brown marks ........................................... ............................................ Polistes communalis, new species 4. Tergum IV without apical yellow band. Sterna II with posterlateral spots & III with narrow apical yellow band ............................ ........................................... Polistes stigma stigma (Fabricius) − Tergum IV with apical broad yellow band. Sterna II–IV with very broad apical yellow bands ................................................ ........................................... Polistes stigma tamula (Fabricius)

Published as part of Nguyen, Lien Thi Phuong, Vu, Thuong Thi, Lee, John, X. Q. & Carpenter, James M., 2017, Taxonomic notes on the Polistes stigma group (Hymenoptera, Vespidae: Polistinae) from continental Southeast Asia, with descriptions of three new species and a key to species, pp. 269-279 in Raffles Bulletin of Zoology 65 on page 278, DOI: 10.5281/zenodo.4502871