Two new species of Formicoxenus Mayr 1855 and Leptothorax Mayr 1855 from Tibet (Hymenoptera: Formicidae) Author Seifert, Bernhard text Soil Organisms 2023 2023-08-01 95 2 129 142 http://dx.doi.org/10.25674/so95iss2id315 journal article 10.25674/so95iss2id315 2509-9523 13193924 Formicoxenus gebaueri n.sp. Etymology: dedicated to the collector Axel Gebauer. Type material: Holotype and 7 paratype workers from the same nest labelled ‘ CHINA : 36.82°N , 102.53°E , Beishan Nat. Park , 2600 m , Picea-Pinus-Wald, Geröllhang. A. Gebauer 1996.05.30 ’ Diagnosis : --Worker ( Figs 14–17 , key). Numeric data given are arithmetic means based on measurement of 5 specimens (for standard deviation, minimum and maximum values see Tab. 1 ). Medium-sized, CS 738 µm.Head elongated, CL/CW 1.253. Genae in dorsal view nearly parallel. Median third of anterior margin of clypeus and hind margin of vertex in dorsal view straight. Frons narrower than in F. sibiricus (FRS/CS 0.432), scape slightly shorter (SL/CS 0.712. Eye very small, EYE/CS 0.164. Dorsal profile of promesonotum and propodeum slightly convex, metanotal depression moderately deep (MGr/CS 2.95 %). Spines rather short and acute (SP/CS 0.153), their bases moderately distant (SPBA/CS 0.289). Petiole with strong anterolateral corners, in profile without peduncle and with a less broad subpetiolar lobe. Postpetiolar sternite with a well-developed spine. All surfaces of head, mesosoma, waist and appendages matt due to a reticulate microsculpture. Dorsal vertex strongly longitudinally carinulate-rugulose. Gaster smooth and shiny but in contrast to F. sibiricus with subdecumbent to semierect setae. Head, mesosoma, waist, and gaster with long (PnHL/ CS 0.128) setae, tapering apicad ( Fig. 17 ) and round in cross-section. Color of head, mesosoma, waist and gaster homogenously yellowish brown. Taxonomic comments . As a combination of long, tapering setae, well-developed sculpture on head, mesosoma, waist and appendages and narrower frons, Formicoxenus gebaueri n.sp. is unmistakable among the Palaearctic Formicoxenus species. Biology . The type sample was collected below a stone within a Picea-Pinus forest on a slope with rubble. The host species was an undescribed species of the subgenus Serviformica Forel 1913 .