Temnothorax silvestrii

Modified from Creighton (1953): An arboreal species that prefers to nest in evergreen oaks, particularly Quercus emoryi. Like most arboreal ants that nest in Arizona, it nests in good sized limbs rather than twigs. The colonies are comparatively small. They contain from 50 to 70 workers with a single queen.



Identification
Mackay (2000) "This species is yellow brown in color with a 12-segmented antenna. The head is completely and coarsely punctate, with fine rugae interspersed among the punctures, The top of the mesosoma and petiolar node have similar sculpture. The side of the mesosoma, side of the petiole and entire postpetiole are similarly punctate, with reduced extensive rugae when compared to the top of the mesosoma. The entire dorsum of the first tergum is evenly, but finely punctate. The petiolar spines are sharp and well developed. The peduncle of the petiole is elongate and the top of the node is truncate and square in shape. All of the femora, especially the hind femur, are incrassate. The maxillary palp has 5 segments, the labial palp 3 segments, the mandible has 5 teeth.

The reticulo-punctate disc of the first gastral tergite separates this species from all others except T. hispidus and T. obliquicanthus, and should separate it from the unknown workers of T. peninsularis. It differs from T. hispidus in that the propodeal spines are well developed and the hind femora are greatly thickened. It differs from T. obliquicanthus in that the eye is normal in shape and the petiolar node is very blunt in profile. It is most similar to T. smithi. but can be easily separated on the basis of the distribution (Arizona, T. smithi is found in eastern US), 12-segmented antenna (11-segmented in T. smithi) and by the rough sculpturing on the surface of the gaster (smooth and glossy in T. smithi). Creighton (1953) considered it to be closely related to T. bradleyi and T. smithi and provides characters to separate them. "

Range
USA: southern Arizona.

Abundance
Only known from a few collections.

Original Combination
Tetramorium silvestrii Santschi, 1911d: 6 (w.) U.S.A. Creighton, 1953f: 5 (q.m.). Combination in Leptothorax: Santschi, 1922a: 68; in L. (Myrafant): Smith, D.R. 1979: 1395; in Temnothorax: Bolton, 2003: 272. See also: MacKay, 2000: 407.

Type Material
Creighton (1953) states samples sent to the Natural History Museum in Basel were compared to the single remaining type, which was from Santschi's collection.

Type Locality
Creighton (1953) "The type locality is given as Tucson but is more likely one of the near-by canyons in the Santa Catalina Mountains. Colonies have not been found below 3500 feet nor does the insect occur in the open desert, which would rule out this species' occurrence in Tucson."

Etymology
Patronym. Named after the Professor Filippo Silvestri.