Material examined. Holotype:1 Ƌ,paratypes:1 Ƌ, 5 ♀. China, Yushu (Qinghai), 4390m, (33°31’07’’N 96°29’94’’E), August, 2019. Coll. Ke-Yao Zhang, Zhi-Cuo Dan & Jun-Jie Ge; deposited in the Zoological and Botanical Museum, Shaanxi Normal University, Xi’an, China (ZBM).
Description. Male (Fig. 2). Body size larger, head shorter than the length of pronotum, slightly oblique in profile; antennae club-shaped, shorter than head and pronotum together, with 11 segments and distinctly wider in apical part; eyes larger, oval, almost of equal diameter with subocular furrow; Pronotum flat, crossed by three sulci, the ventral posterior margin of its lateral lobes rounded; the length of the mesosternum seven times width; wings absent; hind femur 5.4 times longer than its width, its lower basal lobes longer than upper ones, inner sides with three black spots; the lower lobes of hind knee rounded; hind tibia with ten apical spines on both inner and outer sides. epiproct slightly conical, posterior margin protrude with a promontory in the middle; cercus conical; extending to the tip of epiproct; Subgenital plate conical; Epiphallus bridged, ancora bud-shaped, anterior projection bend down; basal valves of penis conical, apex blunt.
Female (Fig. 2). Similar to male but larger and more robust; width of vertex between two eyes 1.8 times wider than frontal ridge between the antennae; epiproct slightly conical, apex acute, with a longitudinal groove in the basal half; valves of ovipositor longer, with slightly obtuse apex, its outer margin serrated; cercus short conical, not reaching the middle of epiproct; subgenital plate subcylindrical, its posterior margin acute.
Coloration. Body and antennae yellowish-brown; eyes darkish-brown; hind femur yellowish-brown on both inner and outer sides, with three black spots on the inner side; hind tibia yellowish-brown; abdomen and subgenital plate yellowish-brown.
Habitat. Alpine desert steppe.
Measurement. (In mm) Body length: Ƌ 10.1-10.5, ♀ 15.1-18.9; pronotum length: Ƌ 1.5-1.7, ♀ 1.6-1.9; hind femur: Ƌ 5.0-5.4, ♀ 6.8-7.5.
Diagnosis. The new species Myrmeleomastax wideis sp. nov. is similar to Myrmeleomastax pulvinella Yin 1984 from Amdo (Tibet) region, China from which it differs by the characters presented in the Table 1 below.
Etymology. The specific epithet is named for a distinct character of this species, because the width of mesosternum of this species is distinctly wider than other species in this genus.