Gauromyrmex orbihumerus

The single collection of this species was made from the trunk of Elaeocarpus decipiens Hemsl., about 1.5 meters above the ground.

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 Gauromyrmex 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 Gauromyrmex 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).