Temnothorax coleenae

Mackay (2000) "The holotype was collected in a pitfall trap on 6 July 1984. The habitat was a creosotebush (Larrea tridentata) desert bajada. Temnothorax coleenae may be nocturnal as it is light colored and has large black eyes."

Identification
Mackay (2000) - A member of the Temnothorax tricarinatus species complex. This is an easily recognized, small, light yellow species with strongly contrasting black eyes and a 12-segmented antenna. Only a few species have this combination of colors and occur in the Chihuahuan Desert.

This species is clearly distinct from all other Temnothorax species. Although a small region posterior to the frontal area is somewhat smooth and shining, the head is almost completely punctated which would preclude any confusion with species such as Temnothorax carinatus, Temnothorax nitens or Temnothorax adustus which usually have a large portion of the dorsum of the head smooth and shining and always have at least some striae on both sides of this shiny region. Also these 3 species are much darker than Temnothorax coleenae. There are no striae on the head of Temnothorax colleenae, except on the malar area, which would eliminate confusion with any of species such as Temnothorax carinatus or Temnothorax furunculus. It is also much lighter in color than these species. The well-developed ventral flange on the anterior peduncle of the petiole also separates it from most of the other similar Temnothorax. This species can be easily distinguished from the light colored Temnothorax bestelmeyeri and Temnothorax cokendolpheri, which have heads with fine striolae, and which are partially smooth and shining. The eye of Temnothorax bestelmeyeri is much larger than the eye of Temnothorax coleenae. It could be confused with Temnothorax liebi and Temnothorax andersoni, in which the heads are also punctate. Both of these species have blunt petlolar nodes, which would allow separation of these species from Temnothorax coleenae.

Distribution
USA. Known only from type locality in south central New Mexico.

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

Habitat
The type was collected in creosote bush (Larrea tridentata) desert bajada.

Abundance
Only known from the type collection.

Biology
Despite extensive pitfall trapping in the area and numerous collecting trips made in all seasons and during both day and night, by numerous individuals, over several years, only the single specimen was collected (at the type locality). This is one of the 7 species which occur in typical Chihuahuan Desert vegetation (the others are Temnothorax andersoni, Temnothorax bestelmeyeri, Temnothorax cokendolpheri, Temnothorax neomexicanus, Temnothorax liebi, Temnothorax bristoli). It may be nocturnal as it is light colored and has large black eyes as other nocturnal desert ants. (Mackay and Mackay 2002)

Castes
Known only from the worker caste.

Nomenclature

 *  coleenae. Leptothorax (Myrafant) coleenae Mackay, W.P., 2000: 335, figs. 37, 102 (w.) U.S.A. Combination in Temnothorax: Bolton, 2003: 271.

Worker
Mandible with well formed apical tooth somewhat longer and darker that others, subapical tooth also well formed, about 1/3 as long as apical tooth, followed by 3 poorly formed teeth; clypeus with well defined median carina and 2 less well defined lateral carinae on each side; antenna with 12 segments (left antenna of holotype missing); dorsum of head almost completely punctate, with small, moderately shiny area posterior to frontal area; striae present on malar area; eye relatively large, occupying about 1/3 length of head, with about 115 facets; propodeal spines shorter than 1/2 distance between bases, flattened laterally, very wide at base; petiole in profIle with relatively sharp apex (Fig. 102), section between upper base and apex straight, region posterior to apex rounded; anterior peduncle with well defined ventral flange which terminates anteriorly in blunt tooth.

Hairs numerous on body, 12 on submentum, 30 on dorsum of head (maximum length 0.07mm), 20 on dorsum of mesosoma (maximum length 0.10mm), petiole with 6 hairs on posterior of node pointing backwards and upwards (maximum length 0.11mm), 8 on posterior of postpetiole (maximum length 0.09mm).

Head punctate, dorsum of mesosoma with fine reticulated rugae, obscured in large part by punctures; side of mesosoma completely punctate with little evidence of rugae; basal face of propodeum with longitudinal striae, posterior face punctate; surfaces of petiole and post-petiole heavily punctate; dorsal surface of gaster strongly shining. Color: pale yellow, eyes black, strongly contrasting with rest of specimen, mandibular teeth dark brown.

Worker measurements: HL 0.66, HW 0.55, SL 0.48, EL 0.21, EW 0.14, WL 0.81, PW 0.16, PPW 0.29. Indices: CI 83, SI 73.

Type Material
Holotype worker. USA New Mexico, Dona Ana Co., 45k NE of Las Cruces on the Long Term Ecological Site.

Etymology
Patronym. "This species is dedicated to the memory of Colleen "Coco" Adelia Whitford"