"Characters examined";"Diagnostic assessment and usage" "Head characters"; "Shape of head in full-face view";"none, no significant interspecific variation observed, not used in this study" "Shape of head in profile *";"high, used in this study" "Shape of mandibles";"none, no significant interspecific variation observed, not used in this study" "Mandibular dentition";"none, no significant interspecific variation observed, not used in this study" "Shape of clypeus";"low, no significant interspecific variation observed, not used in this study" "Presence of median clypeal tooth *";"high, used in this study" "Cuticular apron of clypeus";"none, no significant interspecific variation observed, not used in this study" "Torulo-posttorular complex *";"high, used in this study" "Antennal bulbus";"none, no significant interspecific variation observed, not used in this study" "Antennal scapes *";"high, used in this study" "Antennal pedicel and funiculus";"none, no significant interspecific variation observed, not used in this study" "Anterior tentorial pits";"none, no significant interspecific variation observed, not used in this study" "Parafrontal ridges *";"high, used in this study" Eyes;"none, absent in the worker caste" "Vertex *";"high, used in this study" "Occipital margin in posterodorsal view *";"high, used in this study" "Occiput in posterior view *";"high, used in this study" "Occipital margin in posteroventral view *";"high, used in this study" "Hypostoma *";"high, used in this study" "Mouthparts (maxillae, labium, labrum)";"unclear, none in closed in condition; described in open condition for Z. sarowiwai, but needs further investigation with better preserved alcohol material for μCT scanning" "Tentorium (internal)";"unclear, tentatively examined in this study and appears species-specific, but needs further investigation with better preserved alcohol material for μCT scanning" "Mesosoma characters"; "Mesosoma in profile *";"high, used in this study" "Endosternum (internal)";"unclear, tentatively examined in this study and appears species-specific, but needs further investigation with better preserved alcohol material for μCT scanning" "Transverse mesopleural groove";"moderately variable among species, not used in this study" Propleuron;"none, no significant interspecific variation observed, not used in this study" "Pleural endophragmal pit *";"high, used in this study" Mesopleuron;"moderately variable among species, not used in this study" Metapleuron;"low, no significant interspecific variation observed, not used in this study" "Mesosoma dorsal *";"high, used in this study" Probasitarsus;"low, no significant interspecific variation observed, not used in this study" "Calcar of strigil";"low, no significant interspecific variation observed, not used in this study" "Metasoma characters"; "Levator of petiole";"unclear, not examined in this study, very difficult to virtually dissect" "Petiolar tergum in profile *";"high, used in this study" Laterotergites;"low, no significant interspecific variation observed, not used in this study" "Subpetiolar process of petiolar sternum in profile *";"high, used in this study" "Petiolar tergum in dorsal view *";"high, used in this study" "Disc of petiole";"none, no significant interspecific variation observed, not used in this study" "Subpetiolar process in ventral view *";"high, used in this study" Helcium;"unclear, not examined in this study" "Abdominal segment III in dorsal view *";"high, used in this study" "Abdominal segment III in ventral view *";"high, used in this study" "Posterior end of abdominal segment III in ventral view *";"high, used in this study" "Prora in anteroventral view *";"high, used in this study" "Abdominal segment IV in dorsal view";"moderate, relatively variable within species, not used in this study" "Abdominal segment IV in ventral view";"moderate, relatively variable within species, not used in this study" "Abdominal segment V in dorsal view";"low, no significant interspecific variation observed, not used in this study" "Abdominal segment V in ventral view";"low, no significant interspecific variation observed, not used in this study" "Abdominal segment VI in dorsal view *";"high, used in this study" "Abdominal segment VI in ventral view";"high, not used in this study" "Girdling constrictions abdominal segments IV, V, VI *";"high, used in this study" Pygidium;"low, no significant interspecific variation observed, not used in this study" Hypopygium;"low, no significant interspecific variation observed, not used in this study" "Spiracles abdominal segments II-VII";"none, no significant interspecific variation observed, not used in this study" "General surface sculpture *";"high, used in this study" "Cuticle thickness (internal)";"unclear, examined in this study but needs further investigation with more specimens"