Revision and redefinition of the crematogastrine genus Tetheamyrma

In the article “Revision and redefinition of the crematogastrine genus Tetheamyrma BOLTON, 1991, with the description of a new species and the first description of the dealate queen (Hymenoptera: Formicidae)” by David E.M. General and Perry A. Buenavente recently published in Myrmecological News, the authors revise and redefine this ant genus and describe a new species. Here, Robert Taylor highlights their main points.

A Review compiled by Bob Taylor

This well-executed contribution recognises a new Philippine species Tetheamyrma bidentata, assigned to a genus which was previously represented by the single known Bornean species, T. subspongia Bolton, originally described from Poring, Sabah, in 1991. The worker and Queen castes are well-described and illustrated.

The paper stands as the latest of a growing number of recent taxonomic contributions dealing with or including Philippines ants, which constitute a fascinating and understudied fauna currently receiving attention from a number of authors (including Herbert Zettel, Gary Alpert, and the writer), all vigorously encouraged and supported by David General.

General and Buenavente authenticate the generic identification of T. bidentata by consulting with other specialist myrmecologists. The species differs significantly from T. subspongia in ways that could well have led to an erroneous generic assignment, most likely to Lasiomyrma Terayama & Yamane, species of which are somewhat similar to Tetheamyrma, especially in possessing a 2:2 palpal formula (a feature perhaps related to the small size of these ants, rather than denoting affinity). They also updated the record of subspongia by illustrating it with modern confocal “stepper” photographic images acquired from the Californian Antweb site, and arranged for DNA checking of the proposed relationship by further specialist researchers. This excellent overall diligence in taxonomic research and publication deserves respect and emulation by other myrmecologists.

Interestingly Tetheamyrma subspongia workers have spongiform tissue on the underside of the postpetiole, which is lacking in T. bidentata. This resembles the usually more extensive similar material developed separately and convergently in several genera of dacetine ants, and in the unrelated crematogastrine genus Dacetinops Brown and Wilson, another taxon with Bornean representation which has recently been reported from the Philippines.

Modern Philippines myrmecology is essentially based on the work of James W Chapman (1880-1964), a student of William Morton Wheeler at Harvard University, who served for many years from 1916 at Silliman University in Negros Orientale. In 1941 he and his wife fled to the hills in the Horns of Negros near Dumagete to escape the invading Japanese. They were eventually captured and spent 18 months imprisoned in Manila. Chapman’s ant collection survived the war buried in a cave on Negros. It now reclines in the Museum of Comparative Zoology at Harvard, having survived its Philippine ordeal in very good order (see the book Escape to the Hills by James & Ethyl Chapman (1947)).