Propodilobus pingorum, 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 : 55-56

Propodilobus pingorum (DuBois) comb. n.

(Figures 41-44)

Stenamma pingorum DuBois, 2000: 40. Holotype worker and paratype workers, MALAYSIA: Sarawak, First Division, Semengoh Forest Reserve, 19 km SW Kuching (1.33°N, 110.20°W) (2 km S 10th mile Bazaar, on Kuching-Penrissen Road), 28-31 May 1968, R.W. Taylor, RWT-68.196, leaf mould berlesate in rainforest [Holotype and paratype workers in ANIC examined.] [Replacement name for Stenamma orientale DuBois, 1998: 308-310, Figs 41-43, 210-213 (Junior primary homonym of Messor orientalis (Emery 1898: 143))].

Conclusions

Like many other ant genera in the Myrmicinae , Stenamma has been a problematic genus lacking an adequate morphological diagnosis. Nevertheless, the combination of new collecting techniques, a global perspective, and the use of sequence data, has made it possible to redefine Stenamma with confidence. This new understanding will aid efforts to study the biogeographic history of the genus and to revise the largely unstudied Neotropical fauna.

In contrast to Stenamma , it is clear that Lordomyrma is not a well-defined genus and is in need of a global analysis similar to the one presented here. The molecular work by Lucky and Sarnat (in press) and the ongoing morphological studies of Taylor (2009), offer a strong foundation for the re-examination of generic boundaries. A clearly defined Lordomyrma is critical to putting the aberrant morphological characters of the Stenamma-like taxa L. bhutanensis and L. sinensis into a more satisfying context than can be presented here.

The genus Propodilobus is defined, but its placement within the Myrmicinae is not yet known. It is imperative that more specimens of Propodilobus be collected in order to increase our knowledge of the groups morphological diversity, to provide material for molecular studies, and to confirm the group's proposed generic status.

This is not the first study to show that there are taxonomic problems within the Myrmicinae . Others have suggested or shown that a substantial number of genera and tribes within the subfamily are non-monophyletic (Brady et al. 2006; Moreau et al. 2006; Ward 2007). Most important in terms of classifying Stenamma will be to diagnose the group that contains Aphaenogaster , Messor , and Stenamma . This will likely require a molecular phylogenetic analysis that includes additional genera currently classified as Pheidolini . Establishing new generic limits should proceed in a manner similar to that adopted here. The combination of molecular data and a global analysis of morphology will reveal which characters are most useful in diagnosing natural groupings. It will also help to reveal interesting cases of convergent evolution within the ants.