Key to the Stigmatomma species of Hong Kong SAR, China

Key to the Stigmatomma species of Hong Kong SAR, China, based on workers (from Hamer et al., 2023).

1

 * Antenna segment count 12 (Fig. 3A; Fig. 11A)


 * Antenna segment count 11 (Fig. 5C; Fig. 8B; Fig. 16A; Fig. 17C)

2

 * Large (TL 8.7-10.4); head almost as wide and long (CI 94.46-99.65); eye conspicuous; genal teeth truncated apically (Fig 11A; Fig 14A); cephalic integument immediately adjacent to longitudinal strip with deep foveate pits (Fig 15G-I) Stigmatomma nr. quadratum


 * Small (TL 3.5-4.1); head distinctly longer than wide (87-89.13); eye minute to absent; genal teeth tapering to a point apically (Fig. 3A; Fig. 10D); cephalic integument without deep foveate pits (Fig 3A; Fig. 9C)

3

 * Genal teeth conspicuous (Fig. 3A); dorsolateral propodeal margin lacking margination (Fig. 3B); metanotal groove absent (Fig 3C); median clypeal denticles conical, distinctly extending from the anterior clypeal margin (Fig. 3A) Stigmatomma amblyops


 * Genal teeth present but inconspicuous (Fig. 10D); dorsolateral propodeal margin marginated (Fig. 10E); metanotal groove present, weakly impressed (Fig. 10A); median clypeal denticles small, not distinctly extending beyond anterior clypeal margin (Fig. 10C-D) Stigmatomma pagei

4

 * Antennal scrobes present, nearly reaching the occipital margin (Fig 4A); head longer than wide (CI; 85.4-87.1)) Stigmatomma crypticum


 * Antennal scrobes absent, not reaching occipital margin (Fig. 5B; Fig. 11A); head as wide and long (CI; 100-106)

5

 * Denticles on anterior clypeal margin absent (Fig. 8B-C); mandibles as long as head length (MI 93.3-100) Stigmatomma luyiae


 * Denticles on anterior clypeal margin present (Fig. 5A; Fig. 6D; Fig 7B; Fig. 16A; Fig. 17C); mandibles shorter than head length (MI 52.8-78)

6

 * Smaller (TL 1.88-1.94); third apical mandibular tooth long and jigsaw tab-like (Fig. 16A; Fig. 17C); absence of paired teeth on mandible (Fig. 16A; Fig. 17C); 5 denticles on anterior clypeal margin (Fig. 16A; Fig. 17C) Stigmatomma zwaluwenburgi


 * Larger (TL 2.39); third apical mandibular tooth not jigsaw tab-like, short and recurved upwards instead (Fig. 5C; Fig. 6D; Fig. 7B); presence of paired teeth on mandible (Fig. 5C; Fig. 6D; Fig. 7B); 10 denticles on anterior clypeal anterior margin (Fig. 6D) Stigmatomma draconis