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.

Worker
Long. 3,2-3,4 mil. Jaune pale, mat. pilosite jaune dressee et coupee ras a, la facon des Leptothorax, plus courte sur la tete et l'abdomen remplacee sur les pattes et l'abdomen par une pubescence tres courte.

Devant de la tete ridee en long, ride-reticulee sur les cotes avec un fond finement ponctue. Clypeus assez fortement strie en long. Mandibules plus finement striees. Thorax rugueux, plus grossierement ride-reticule que la tete sauf entre les epines et sur un espace situe au milieu du dos ou predomine la ponctuation fondamentale. Pedicule rugueux. Premier segment abdominal finement reticule ponctue, les autres lisses.

Tete rectangulaire bien plus longue que large, yeux bormbes au milieu de ses cotes. Cretes frontales courtes non prolongees, aire frontale lisse, triangulaire, presque aussi longues que les cretes. Clypeus bombe non carene. Mandibules armees d' une dent apicale assez forte suivie de 4-6 denticules espaces. Antennes de 12 articles massue allongee dont Ie 2eme article est bien plus de deux fois plus long que large. Profil du thorax rectiligne un peu abaisse dans son tiers anterieur. Suture promesonotale assez distincte, la mesoepinotale effacee. Epines sensiblement plus longues que l'intervale de leur base, dirigees en arriere et en haut, divergeantes. Premier article du pedicule d' un quart plus long que haut avec un noeud cubique un peu arrondi en avant bien plus long que est suivant qui est environ d'un tiers plus large en ovale transversal. Premier segment de l'abdomen assez rectangulaire avec son bord anterieur legerement echancre.

Queen
brown questioned if Creighton's (1953) silvestri description was actually of this species....see notes in reprint of the paper from Brown's article library.....ask stef

Male
brown questioned if Creighton's (1953) silvestri description was actually of this species....ask stef

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.