Pseudomyrmex perboscii

Distribution
This taxon was described from Mexico.

Biology
In northern Colombia and Venezuela I collected colonies of this species in live terminal branches of saman (Pithecellobium saman) trees. The ants occupied numerous unconnected cavities, 5-20 mm long (2-4 mm internal diameter) in which they kept brood and tended coccids. The cavities appeared to be intrinsic to the plant since unoccupied cavities, without entrance holes, could be found. Although the workers patrolled the foliage and would sting if molested, they were much less aggressive than the Pseudomyrmex ants inhabiting Tachigali, Triplaris, or swollen-thorn acacias. Thus the association may represent an early (or arrested?) phase in the development of an ant-plant mutualism. (Ward 1989)

Nomenclature

 *  perboscii. Myrmex perboscii Guérin-Méneville, 1844a: 428 (q.) MEXICO. Forel, 1899c: 86 (w.). Combination in Pseudomyrma: Smith, F. 1858b: 156; in Pseudomyrmex: Kempf, 1972a: 222. Senior synonym of icterica, simoides, testacea: Ward, 1989: 442.
 * testacea. Tetraponera testacea Smith, F. 1852: 45 (footnote) (w.) SOUTH AMERICA. Smith, F. 1855c: 168 (w.). Combination in Pseudomyrma: Smith, F. 1855c: 168; in Pseudomyrmex: Kempf, 1961a: 400. Junior synonym of perboscii: Ward, 1989: 442.
 * simoides. Pseudomyrma simoides Forel, 1911e: 281 (w.) BRAZIL. Combination in Pseudomyrmex: Kempf, 1961a: 399. Junior synonym of perboscii: Ward, 1989: 442.
 * icterica. Pseudomyrma icterica Wheeler, W.M. 1922c: 4 (w.) TRINIDAD. Combination in Pseudomyrmex: Kempf, 1961a: 399. Junior synonym of perboscii: Ward, 1989: 442.

Ward (1989) - This medium-sized species (worker HW 1.09-1.44, n=15) has a truncate median clypeal lobe, which is sharply rounded laterally; relatively well-separated frontal carinae (MFC subequal to distal scape width) and conspicuously protruding median lobes of the antennal sclerites; a deeply incised metanotal groove (in the worker); and a somewhat shiny, orange- to testaceous-brown, integument, the gaster sometimes darker in color. The head and mesosoma have fine, puncticulate sculpture, the punctulae varying in density, as do the minute, piligerous punctures (and associated appressed pubescence) on the postpetiole and gaster. Standing pilosity is fine and rather sparse (lacking on outer faces of the tibiae and on the worker mesonotum).

Having examined the types of P. testaceus, P. simoides, and P. ictericus, I feel fairly confident about the specific identity of these three. Moreover, they appear to be conspecific with the "Pseudomyrma perbosci" worker described by Forel (1899) from Costa Rica. Unfortunately, the type of P. perboscii could not be located, but the original description, while scanty, contains enough information to justify the above synonymy. Among the features mentioned by Guerin, the combination of the elongate, subrectangular head (nearly twice as long as wide), globose postpetiole, fawn-yellow body with dark gaster, finely shagreened to shiny appearance, and large size (9.5mm long), fits the queen of no other species known to me.

Type Material
Holotype queen, Baie de Campeche, Mexico (Perbosc) (not in, , or ) [Not examined].

Tetraponera testaeea Holotype dealate queen, [Rio] Napo, Peru [Examined].

Pseudomyrma simoides Syntype worker, Amazonas, Brazil (Bates) [Examined].

Pseudomyrma ieterica Holotype worker, Port of Spain, Trinidad (A. Busck) [Examined].