Lordomyrma sinensis, Branstetter, M. G., 2009

Branstetter, M. G., 2009, The ant genus Stenamma Westwood (Hymenoptera: Formicidae) redefined, with a description of a new genus Propodilobus., Zootaxa 2221, pp. 41-57 : 49-50

Lordomyrma sinensis (Ma, Xu, Makio, and DuBois) comb. n.

Stenamma sinensis Ma, Xu, Makio, and DuBois, 2007: 371-377, Figs. 1-4. Holotype worker and paratype workers, CHINA: Mt. Qinling, Shaanxi, 33°39'N 107°48'E, 1580-1641m, 7-18 September 2005 and 1-13 August 2006, LiBin Ma. [Holotype and partype workers in DBSNU not examined.]

Justification for transfer of species to Lordomyrma

Morphological analysis

The holotype and several paratype specimens of Lordomyrma bhutanensis from the NHMB were examined. Additional material recently collected from Nepal and Yunnan Province, China was borrowed from MCZC and CASC, respectively. These latter specimens were sorted into two morphospecies and identified as L. cf. bhutanensis 1 and L. cf. bhutanensis 2 (Figures 28-33). Careful examination revealed several morphological characters distinguishing these species from Stenamma : (1) Antenna with a 3-segmented club of which the last two segments display the largest increases in length relative to preceding segments (ACI 73- 77; compare Figures 34 and 37); (2) apex of anterior clypeal margin with a small projecting tooth (compare Figures 35 and 38; note, this character was not discerned in the types of L. bhutanensis because the mandibles were closed in all specimens); (3) posteromedial margin of clypeus as wide or wider than frontal lobes in full-face view (compare Figures 35, 38); (3) postpetiolar node broader than long (Figures 27, 30, 33); (4) sting robust and often exposed and projecting dorsally in pinned specimens (compare Figures 36 and 39). Although specimens of L. sinensis were not examined, the characters mentioned above were confirmed by reviewing the species description and accompanying figures (Ma et al. 2007).

To adequately delimit species in this group, a more detailed analysis of regional variation will be necessary. From the specimens examined here, I find it difficult to comfortably define species boundaries. Surprisingly, Ma et al. (2007) did not directly compare L. sinensis to L. bhutanensis , but instead stated that it would most likely be confused with other species within the Stenamma owstoni species group, the group to which both L. sinensis and L. bhutanensis were assigned. I examined three additional members of this species group, S. koreanensis, S. owstoni , and S. nipponense (Figures 5-7), and determined that these have the attributes of true Stenamma . It is likely that this confusion was caused by a poor understanding of which characters are most important in diagnosing Stenamma . For example, Ma et al. (2007) were the first to notice the presence of a median clypeal tooth. However, they incorrectly used this trait as a species diagnosing rather than a genus diagnosing character.