Polyrhachis flavicornis, Smith, 1857

Jaitrong, Weeyawat, Yamane, Seiki & Noon-Anant, Nawee, 2023, The Thai species of the Polyrhachis (Myrmatopa) flavicornis Smith, 1857 species group, with description of a new species (Hymenoptera, Formicidae Formicinae), Zootaxa 5249 (4), pp. 446-464 : 448

Polyrhachis flavicornis species group

Diagnosis. Members of the species group can be distinguished from other species groups by the following characteristics: 1) the mesosoma that is box-like and dorsolaterally marginate throughout its length; 2) pronotum in dorsal view convex median portion and narrowed posteriorly, armed with humeral teeth; 3) propodeal spine short and directed upward; 4) petiole in lateral view with anterior slope distinctly convex; 5) petiole with two spines dorsolaterally, without denticles between the spines; 6) petiolar spine in lateral view curved backwards, as long as or longer than the height of petiole. This species group is most similar to the Polyrhachis wallacei species group but can be separated by 1) pronotum dorsolaterally marginate throughout its length (pronotum dorsolaterally not marginate in P. wallacei group); 2) humerus armed with teeth or denticle (unarmed in P. wallacei group); 3) petiole in profile view with anterior slope distinctly convex (anterior slope almost straight in P. wallacei group); 4) petiolar spine in profile view curved backwards (vertical and almost straight in P. wallacei group).