Formica orangea

Description of worker (Tab. 1, Fig. 6): medium-sized Serviformica species (CS 1.349 mm), head short (CL / CW 1.4 1.111), scape shortest and distance of lateral ocelli largest within the F. rufibarbis group (SL / CS 1.4 1.021, OceD / CS 1.4 0.172), eye relatively small (EYE / CS 1.4 0.288), petiole relatively narrow (PEW / CS 1.4 0.421). Clypeus with sharp median keel and fine longitudinal microcarinulae. Frontal triangle finely transversely rippled and with 35 - 60 short pubescence hairs. Eyes with microsetae of 10 - 13 μ m maximum length. Total mean of unilateral setae numbers on different body parts predicted for a specimen with CS = 1.4 mm: pronotum 1.5, mesonotum 0.8, petiole scale dorsal of spiracle 0.2, flexor profile of hind tibia 0.3. Posterior margin of head and propodeum plus dorsolateral metapleuron normally without setae. Ventral coxae and gaster tergites with long setae. Dorsal mesonotal profile broadly rounded. Metanotal depression moderately deep. Propodeal dome in profile flatly rounded to angled, the basal profile sometimes slightly concave. Dorsal crest of petiole in frontal view broadly convex. Petiole scale in lateral aspect relatively low and thicker than in other species of the F. rufi-barbis group, except F. tarimica sp. n., with convex anterior and straight to slightly convex posterior profile. Gaster with transverse microripples of rather large distance (RipD 6.7 μ m, second largest within the F. rufibarbis group) and covered by dense silvery pubescence (sqPDG 3.15). Pubescence on head, mesosoma and petiole less dense. Whole head, mesosoma, coxae, all appendages, and petiole in typical cases reddish yellow; sometimes in smaller specimens brown spots may occur on posterior vertex and dorsal pro-mesonotum, but always with low contrast between the pig-mented and the light parts, gaster always brown.