Temnothorax rudis

Summarized from Ward (2005): Colonies can be found in rotten wood, under stones, in fallen acorns, and in the leaf litter. Common in mixed coniferous forests of California, up to about 1750m elevation.

Identification
Ward (2005) "Temnothorax rudis is readily distinguished from Temnothorax nevadensis by petiole shape. In Temnothorax rudis the petiole is broader in profile, with the anterior and posterodorsal faces meeting at approximately 90º, and the posterodorsal face declining gently. In Temnothorax nevadensis the petiole is more slender in profile, with the anterior and posterodorsal faces forming an acute angle. In addition Temnothorax rudis has coarser body sculpture and is lighter in color than Temnothorax nevadensis."

Distribution
Western Canada and United States: coastal, including California, Oregon, Washington and SW British Columbia

Distribution based on Regional Taxon Lists
Nearctic Region: Canada, United States.

Habitat
mixed coniferous forest

Abundance
common in some parts of its range

Nomenclature

 *  rudis. Leptothorax nevadensis subsp. rudis Wheeler, W.M. 1917a: 508 (w.q.) U.S.A. Combination in Temnothorax: Ward, 2005: 19. Junior synonym of nevadensis: Mackay, 2000: 376. Revived from synomymy and raised to species: Ward, 2005: 19.

Worker
Worker. Length 2.6-3.3 mm. Distinctly larger and more robust than the typical nevadensis and much more coarsely sculptured. Funicular joints 2-8 distinctly broader in proportion to their length. Head subopaque, finely and densely longitudinally rugose, with punctate interrugal spaces and sometimes with an interrupted shining median line. Frontal area shining; very finely striated. Mandibles coarsely punctate, striated at their bases. Thorax and petiole coarsely punctate-rugose, the rugae on the pleurae and often also on the pro- and epinotum longitudinal, on the mesonotum often vermiculate. Declivity of epinotum densely punctate and as opaque as the remainder of the thorax (more shining in the typical form). Postpetiole densely punctate and opaque. The epinotal spines are much stouter and blunter, and the petiolar node is much less compressed anteroposteriorly, its posterior surface being much more convex than in typical nevadensis. The color is considerably darker, the body being castaneous, with the head and gaster, except its incisures, blackish, the mandibles, clypeus, antennae and legs yellowish brown, the femora infuscated in the middle. Pilosity as in the typical form.

Queen
Smaller than the female of typical nevadensis, with longer and more slender epinotal spines and the funicular joints 2-8 shorter. Sculpture of the head, thorax and petiole a little coarser. Petiolar node like that of the worker. In the typical form it is much compressed anteroposteriorly and has a sharp, transverse superior border. There is very little difference in color between the two forms.

Male
Males are known for this species but they have not been described.

Type Material
Presumably MCZ and USNM.

Type Locality Information
Described from numerous workers and a single female taken from small colonies nesting under the edges of stones in Tenaya Canyon, Yosemite Valley, Cala.

Additional References

 * Snelling, R.R., Borowiec, M.L. & Prebus, M.M. 2014. Studies on California ants: a review of the genus Temnothorax (Hymenoptera, Formicidae). ZooKeys 372, 27–89 (doi: 10.3897/zookeys.372.6039)
 * Ward, P. S. 2005. A synoptic review of the ants of California (Hymenoptera: Formicidae). Zootaxa. 936:1-68.
 * Wheeler, W. M. 1917. The mountain ants of western North America. Proceedings of the American Academy of Arts and Sciences. 52:457-569.