Temnothorax liebi

Temnothorax liebi has been found nesting in soil in creosote bush scrub in the Chihuahuan Desert. Their light color and large eyes suggest this is a species that is active nocturnally.

Identification
Mackay (2000) - A member of the Temnothorax andersoni species complex. This is a small, pale yellow, nearly white ant with dark eyes. It is soft bodied, and usually becomes distorted when dried on a point. It can be easily distinguished by the large eyes, which have a maximum diameter greater than the distance between the anterior border of the eye and the base of the mandible. The antenna has 12 segments, the head is heavily and densely punctate, with the punctures forming weak striae. The propodeal spines are poorly developed, forming small angles. The petiolar node is truncate. These characters will actually separate it from all other members of the genus.

This species could be confused with Temnothorax terrigena or Temnothorax punctatissimus, and could be easily separated with the characters in the diagnosis. It somewhat resembles Temnothorax coleenae in terms of sculpture, but differs in having the large eyes and a blunt petiolar node. The discussion of Temnothorax coleenae includes suggestions as to how to distinguish the pale, desert species, including Temnothorax andersoni, Temnothorax bestelmeyeri, Temnothorax cokendolpheri, Temnothorax coleenae, and Temnothorax liebi. The large eye may cause it to be confused with Temnothorax obliquicanthus, but the eye is not kidney shaped and the first tergum of the gaster is entirely smooth and shining, not sculptured as in Temnothorax obliquicanthus. Therefore there is little likelihood that this species would be confused with any other. This is another species of the Chihuahuan Desert that is pale yellow in color with dark eyes. These are presumably adaptations to nocturnal foraging, although the specimens at Van Horn were collected actively foraging at the nest entrance during the day. This coloration appears to be the result of convergent evolution, as these pale, desert species seem to have little in common morphologically other than color.

Distribution
USA. Known only from southwestern Texas.

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

Habitat
Collected from creosote bush scrub in the Chihuahuan Desert.

Abundance
Only known from a few collections.

Castes
Only known from the worker caste.

Nomenclature

 *  liebi. Leptothorax (Myrafant) liebi Mackay, W.P., 2000: 353, figs. 16, 36, 42, 121, 122 (w.) U.S.A. Combination in Temnothorax: Bolton, 2003: 271.

Worker
Mandibles with 5 teeth, basal most small, less than half volume of distal 2 teeth; anterior border of clypeus convex, clypeus with poorly defined medial carina and several weak lateral carinae; sides of head convex, wider anterior of eyes than posterior to eyes; vertex weakly concave; eyes very large, extending well past sides of head; mesosoma with none of the sutures interrupting sculpture, dorsum nearly straight; propodeal spines developed as small angles, acute apex, base broad; petiole with subpetiolar process well developed, anterior petiolar face concave, posterior face short (0.05mm), and convex, petiolar node obliquely truncate in profile; postpetiole wide, nearly 1.5 X length.

Erect hairs scattered on most surfaces, mostly coarse and dull at apices; decumbent pubescence nearly absent, except on legs and antennae.

Sculpture consisting primarily of dense punctures, entire dorsum of head punctate, (lining up into faint striae on head), some small areas on head shiny, but most surfaces dull, mesosoma, petiole and postpetiole densely punctate, with a few poorly defined rugae on sides of mesosoma, entire gaster smooth and polished. Concolorous pale yellow with strongly contrasting black eyes.

Worker measurements: HL 0.58-0.64. HW 0.52-0.53. SL 0.44-0.47. EL 0.19-0.22. WL 0.70-0.77. PW 0.13-0.18. PL 0.16-0.20. PPW 0.19-0.29. PPL 0.14-0.19. Indices: CI 83-90. SI 73-79. PI 81-150. PPI 136-153.

Type Material
Holotype worker, USA, Texas: Hudspeth Co ., 25 KSW Van Hom, 27-x-1991, W. Mackay #15465 and paratype worker, USA, Texas, Hudspeth Co., 25 KSW Van Horn, 25-viii-1991, W. Mackay #15149.

Etymology
Patronym. "Named in honor of my close friend and colleague, Dr. Carl Lieb, previous director of the Indio Mountain Research Station, who has made major efforts in promoting and preserving the research station.

References based on Global Ant Biodiversity Informatics

 * Mackay W. P. 2000. A review of the New World ants of the subgenus Myrafant, (genus Leptothorax) (Hymenoptera: Formicidae). Sociobiology 36: 265-444.
 * Mackay W. P., and E. E. Mackay. 2002. The ants of New Mexico (Hymenoptera: Formicidae). Lewiston, New York: Edwin Mellen Press, 400 pp.
 * Mackay, W.P. and E. Mackay. XXXX. The Ants of New Mexico