Temnothorax furunculus

Nests under stones in pinyon-cedar woodlands (Wheeler, 1909; Gregg, 1963). It has also been found in sagebrush habitat in Utah (Allred 1982).

Identification
Mackay (2000) - A member of the Temnothorax tricarinatus species complex. The workers of this species are yellow brown with a 12 segmented antenna. The clypeus has a single median carina, 2 prominent lateral carinae and a few others, which are poorly defined. The head has wavy rugae, forming concentric semicircles around the insertion of the antennae, the striae posterior to the eyes are directed posteriorly to the occipital lobes, the central area of the head has poorly defined striae and is partially smooth and shining. The top of the mesosoma is covered with punctures and fine rugae, the sides near the top have somewhat coarse rugae. The pronotum has striae, the mesopleuron and side of the propodeum are covered with punctures. The propodeal spines are small, but well formed. The petiolar node is moderately sharp, as seen in the subpeduncular process, is large and well developed. The surface of the petiole and postpetiole are covered with punctures. The dorsum of the gaster is smooth and polished.

This species could be confused with Temnothorax nevadensis or Temnothorax andrei. It differs from these species in that the petiolar node is moderately sharp at the apex (rounded in Temnothorax nevadensis and Temnothorax andrei) and the hairs on the petiole and postpetiole are only very slightly spatulate, or simply truncate. It is similar in color to Temnothorax andrei, but has propodeal spines, which are about 1/2 the length of the distance between their bases, not simply angles as in Temnothorax andrei. The clypeus is completely different from that of Temnothorax andrei possessing a single medial carina and two prominent lateral carinae, not a series of poorly defined carinae as in Temnothorax andrei. It could be confused with Temnothorax rugithorax, but differs in the node of the petiole having a sharp apex (truncate and square shaped in Temnothorax rugithorax). It can be separated from Temnothorax neomexicanus, but is lighter in color and has a much more developed subpeduncular process. Wheeler (1909) states that Temnothorax furunculus has a distinct mesopropodeal impression, which is correct, although the impression is poorly developed and not much more notable than in most of the other species in the subgenus.

Distribution
USA. Wyoming, Colorado, Utah.

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

Habitat
Collected from pinyon-cedar woodland and sagebrush habitats.

Abundance
Only known from a few collections.

Castes
Known only from the worker caste.

Colorado
Gregg (1963) "Until the present investigations were undertaken, this species was not known from other than type material. Although we have not succeeded in finding topotypes, we have discovered the ant in the southwestern portion of Colorado on Mesa Verde.We have also received specimens from Dr. D. C. Lowrie, who collected them on Signal Mountain and in the Jackson Hole Wildlife Park near Moran, Wyoming. As the species must still be considered exceedingly rare, it is not possible to describe its distribution in detail, but enough information has come to light to enable one to visualize the general extent of its range. It would appear to be a Rocky Mountain insect."

Nomenclature

 *  furunculus. Leptothorax furunculus Wheeler, W.M. 1909e: 82 (w.) U.S.A. Combination in L. (Myrafant): Smith, D.R. 1979: 1393; in Temnothorax: Bolton, 2003: 271. See also: Mackay, 2000: 344.

Worker
Worker. - Length 2-2.6 mm.

Head longer than broad, subrectangular, with very feebly emarginate posterior border and slightly convex sides, with the eyes slightly in front of their middle. Mandibles 6-toothed. Clypeus convex, with rounded, entire, rather projecting anterior border, its disc with a longer median and a pair of shorter lateral carinae. Antennae 12-jointed; scapes not reaching the posterior corners of the head; first funicular joint as long as joints 2-5 together; joints 2-7 narrow, subequal, broader than long, joint 8 as long as broad; club 3-jointed, its two basal joints subequal, together shorter than the terminal joint. Thorax somewhat narrower behind than in front, with rounded humeri; dorsum flattened, with a distinct mesoepinotal suture and impression. Epinotal spines about as long as broad at their bases, rather acute, further apart than long, directed upward and slightly outward and backward. Petiole nearly twice as long as broad, slightly broader behind than in front, with straight sides; in profile with rather thick peduncle, armed with an acute antero-ventral tooth; node high and acute, its anterior declivity concave, the posterior shorter, more abrupt and feebly convex. Postpetiole subrectangular, a little broader than the petiole and somewhat broader than long, with subparallel sides and distinct anterior angles; in profile with low, rounded node. Gaster rather large, elliptical, with rounded anterior corners. Legs of usual shape.

Mandibles opaque, indistinctly striato-punctate. Clypeus and frontal area shining, sides of the former longitudinally rugulose. Head, thorax, petiole and postpetiole subopaque or glossy; gaster glabrous, legs somewhat less shining. Head very finely longitudinally rugulose and reticulate. Thorax, petiole and postpetiole covered with dense, shallow punctures, thoracic dorsum also very indistinctly and longitudinally rugulose.

Hairs yellow; on the body sparse, erect, obtuse but hardly clavate; on the legs and scapes replaced by delicate appressed pubescence.

Yellow; thorax, petiole and postpetiole pale brown; head, excluding the mandibles, clypeus, cheeks and gula, dark brown; gaster dark brown or blackish above, with the posterior edge and a broad band across the anterior portion of each segment, yellow. Antennal clubs slightly infuscated. Mandibular teeth black.

Type Material
Mackay (2000) - Colorado, Williams Canyon near Manitou, 7,500', [seen]."