Gauromyrmex orbihumerus

Identification
Anteromedian margin of clypeus concave. In lateral view, dorsum of pronotum convex; dorsum of mesonotum almost straight, and leaning forward slightly; dorsum of propodeum convex and declining posteriorly, about 1.5 times as long as its declivity, forming a tooth between dorsal margin and declivity, declivity concave. In dorsal view, humeral corners of pronotum rounded. Subpetiolar process triangular translucently; anterior 5/6 part of head with longitudinal stria; dorsum of promesonotum shiny, with fine stria; lateral face of mesosoma rugose longitudinally, dorsum of propodeum punctate-reticulate.

The new species is extremely similar to G. acanthinus, but can be distinguished from the latter by the following characters of workers: humeral corners of pronotum rounded in dorsal view; anterior 5/6 part of head with longitudinal stria, and rest of head shiny, dorsum of promesonotum fine stria; lateral face of mesosoma rugose longitudinally; dorsum of propodeum punctate-reticulate. In addition, the difference between this species and G. bengkalisi is shown in couplet 2 of the key.

Distribution based on Regional Taxon Lists
Palaearctic Region: China.

Nomenclature

 * . Gauromyrmex orbihumerus Chen & Chen, 2022: 8, figs. 14-16 (w.) CHINA (Guangxi).

Type Material

 * Holotype worker, CHINA: Guangxi, Daxin, Xialei Protection Zone, 22.58°N, 106.75°E, 24.Ⅶ.2018, leg. Zhilin Chen, No. G187739.
 * Paratypes: 2 workers from the same colony as the holotype worker. Type workers deposited in GXNU (Insect Collection, Guangxi Normal University, Guilin, Guangxi, China).