Temnothorax rugithorax

Identification
Mackay (2000) " This is a small (less than 2mm total length) brown species in which the head is covered with rugulae and the mesosoma is covered with coarse rugae. The clypeus is convex, nearly smooth and shining with a well-developed median carina. The head is partially glossy and shining. The antenna has 12 segments. The propodeal spines are tiny and the petiolar node is broadly rounded as seen in proflle. The postpetiole is about 1.5 times as wide as the petiole.

The sculpture of the head and mesosoma, and the shape ofthe petiolar node will separate this species from all others in the subgenus. It would be most likely to be confused with Temnothorax tricarinatus, which also has a wide postpetiole. It can be easily separated by the much finer sculptured head, and in being much smaller. The shape of the node could cause it to be confusedwith Temnothorax peninsularis (known only from the female from Baja California). The petiole has a short peduncle and the propodeal spines are poorly developed in Temnothorax rugithorax, workers of Temnothorax peninsularis would be expected to have a well-developed peduncle and well developed propodeal spines. The simple propodeal angles would separate it from Temnothorax gallae and Temnothorax nevadensis, which have propodeal spines that are at least 1/2 the distance between the bases. The blunt petiolar node would separate it from Temnothorax furunculus, which has a node with a sharp apex, and Temnothorax andrei in which the top ofthe node is rounded. Additionally the side of the mesosoma of Temnothorax rugithorax is coarsely sculptured, whereas the side ofthe mesosomae of Temnothorax furunculus and Temnothorax andrei are densely and evenly punctate. It could be confused with Temnothorax rugulosus, but differs as the propodeal spines are much less developed, the pronotum has only fine rugae, and the mesonotum is punctate. "

Distribution
MEXICO, Hidalgo.

Abundance
Only known from types.

Worker
Mandibles with 5 (? difficult to see mandible) teeth; anterior border ofclypeus convex, clypeus with medial carina and a few poorly defined lateral carinae; vertex straight; mesosoma without sutures breaking surface; propodeal spines poorly developed, consisting of tiny angles with acute points; petiole with well developed subpetiolar tooth, petiolar node rounded and blunt in proflle. Erect hairs scattered on most surfaces, most hairs less than 0.05mm in length, a few up to 0.lmm, absent on scapes and lower legs, where smaller, decumbent hairs are present, hairs on coxae to femora erect, but fmer than those on remainder of body. Sculpture coarse, consisting of striae on upper surface of head, clypeus and area posterior to frontal area smooth and shining, dorsum of mesosoma and sides of pronotum covered with coarse rugae, with dense punnctures in intrarugal areas, mesopleuron and propodeum with rough sculpture, consisting in part of punctures, petiole rugose with scattered punctures, postpetiole roughly sculpturedwith coarse punctures, gaster polished and shining.

Color: medium brown.

Female and male: Unknown.

Worker measurement (mm): HL 0.66, HW 0.54, SL 0.44, EL 0.14, WL 0.71, PW 0.18, PL 0.23, PPW 0.26, PPL 0.17. Indices: CI 82, SI 67, PI 78, PPI 153.

Queen
No Queens known for this species.

Male
No Males known for this species.

Type Material
Holotype worker (MCZC).

Type Locality Information
MEXICO, Hidalgo, EI Chico, 23-ix-1938, L. J. Lipovsky.

Etymology
Morphology. "Name based on the rugose mesosoma."

Additional References

 * MacKay, W. P. 2000. A review of the New World ants of the subgenus Myrafant, (Genus Leptothorax) (Hymenoptera: Formicidae). Sociobiology. 36:265-444.