Camponotus texanus

Of this handsome species I have seen only four colonies, all taken in Travis County, Texas. Three of these were in oak logs that had been brought to Austin from the mountain canons northwest of the city. The remaining nest was found in Bull Creek Canon in a crevice between two huge rocks. The males and winged females were taken in two of the nests Feb. 28, 1901, and March 25, 1902. (Wheeler 1903) This species is apparently restricted to Texas.

Identification
C. texanus appears to be closely related to Camponotus sayi of Arizona and Mexico. It is sufficiently distinct, however, both in size, coloration, shape of clypeus, petiole, etc.

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

Nomenclature

 *  texanus. Camponotus texanus Wheeler, W.M. 1903b: 108, fig. 10 (s.w.q.m.) U.S.A. Combination in C. (Myrmentoma): Emery, 1920b: 257; in C. (Camponotus): Forel, 1914a: 266; Creighton, 1950a: 371.

Worker
Major Length 10-12 mm.

Mandibles small, convex, 5-toothed. Head large, about as broad as long, distinctly wider behind than in front, sides moderately convex, posterior border straight when the head is viewed squarely from the front. Clypeus a little longer than broad, not keeled in the middle, its anterior border with a shallow median excision bounded on either side by a prominent tooth. Frontal area small, obscure. Frontal carinae prominent, lyrate. Front with a median groove accentuated by a longitudinal depression towards its posterior end. Cheeks rather uneven, with a deep impression or dimple at the lateral border of the clypeus. Eyes broadly elliptical, flattened. Antennal scape barely reaching the posterior corner of the head, slender and slightly flattened at the base, thicker and more cylindrical towards the distal end; funiculus slender, consisting of joints more than twice as long as wide. Thoracic dorsum regularly arcuate in profile; pro- and mesonotum somewhat flattened dorsally, the former distinctly carinate along its anterior border; pleurae, especially the meso- and metapleurae compressed and flattened; epinotum with a short, slightly concave declivity passing evenly into the rounded basal portion. Sutures, except those between the meso- and metapleurae, distinct. Petiole thick, with convex anterior and very flat posterior surfaces, which form a rather abrupt angle at the summit of the node. From behind the margin of the node is evenly arcuate, passing without angles into the lateral contours. Gaster and legs of the usual shape.

Surface of body finely shagreened, smooth and shining, especially the posterior corners of the head which are highly polished. Head covered with punctures, which are coarse and conspicuous on the mandibles, clypeus, and cheeks but smaller and sparser on the remainder of the head, and especially on the posterior angles. Vertex with eight foveolate piligerous impressions in two rows of four each. Mesonotum with a few coarse piligerous punctures near the middle of its dorsal surface. Legs rather finely punctate.

Hairs on the body suberect, yellow, not abundant. On the head they are found as a row on the anterior border of the clypeus, scattered over the front and more abundant on the lower surface of the head. Mandibles with a few short hairs. Thorax with a few scattered hairs on the pro- and mesonotum and on the epinotal angle. Petiolar node fringed with a single row of hairs. Each gastric segment with two regular transverse rows, one near the base and the other near the posterior margin. There are a few scattered long hairs on the femora and tibiae and at the tip of the antennal scape; tibiae and tarsi with more numerous and smaller appressed hairs.

Head black; mandibles, clypeus, front and lower surface suffused with blood-red. Thorax and petiole rich yellowish red, the sutures of the former black. In some specimens the anterior surface of the petiole is more or less blackened. Gaster black, posterior edges of segments yellow, basal half of first segment and much of the venter rich yellowish red. Legs yellowish red, tibiae and tarsi of a somewhat deeper shade than the femora. Antennal scape, black, suffused with red, funiculus red.

Media Length 9-10 mm.

Resembling the worker maxima throughout except in the smaller size and shape of the head, which is distinctly longer than wide, oblong, with subparallel sides. The blood-red color is somewhat more general on its anterior half. The antennal scapes extend to about one fourth their length beyond the posterior angles.

Minor Length 8-9.5 mm. Closely resembling the maxima and media except in the size of the body and the shape and proportional size of the head, which is much longer than broad, with long, parallel cheeks, somewhat narrower posterior corners, and distinctly concave posterior border. The five teeth of the more slender mandibles are more acute. The clypeus is subhexagonal, broader than long, and coextensive with the anterior border of the head; truncated and somewhat irregular at its anterior margin but not excised or toothed. Antennal scapes long and slender, not flattened at their bases, surpassing the posterior angles of the head by fully half their length. Eyes more narrowly elliptical and more convex than in the media and maxima. In the thorax the sutures bounding the metanotum are vague. There are no differences in color except that the antennal scapes are of a paler red.

Queen
Length 12-12.5 mm.

Resembling the maxima and media, the head like the head of the latter, longer than broad, somewhat narrower in front than behind, with straight posterior border and subparallel sides. The structure of the thorax exhibits the usual sexual characters; the pronotum is prominently marginate in front, transversely convex behind, just in front of the pronounced pro-mesonotal suture. Mesonotum convex in iront, flattened behind. Epinotum broad and rounded dorsally, with its declivity like that of the worker maxima. Edge of petiolar node excised in the middle.

Sculpture and coloration as in the maxima with the following differences: Mesonotum anteriorly with a large, elongate, median, black blotch and a similar blotch on either side over the parapsidal furrow. Alar insertions, scutellum, posterior borders of the paraptera, and the whole metanotum black; disc of scutellum blood-red; epinotum and pronotum slightly infuscated, the former along its sides, the latter along its posterior border. Both the anterior and posterior basal surfaces of the petiolar node more or less blackened. Wings hyaline, strongly suffused with yellow, tips more colorless; veins and stigma brownish yellow.

Male
Length 8-9 mm.

Head small, excluding the slender, edentulous mandibles, very nearly as broad as long; narrower through the cheeks, which are subparallel and slightly concave, than behind the eyes; evenly rounded posteriorly. Clypeus shaped somewhat like that of the worker minor, its anterior much broader than its posterior margin, without teeth or excision. Antennae long and slender, scape cylindrical, exceeding the posterior angle of the head by about two thirds of its length; first funicular joint slightly thicker than any of the succeeding joints. Thorax large and robust, conspicuously broad through the alar insertions, with very convex and rounded scutellum and epinotum. Petiole low, very thick antero-posteriorly, convex both on the anterior and posterior surfaces; edge of node rather blunt, in some specimens with a median excision, in others straight and horizontal. Gaster elongate elliptical, dorso-ventrally compressed. Genitalia small and slender, exserted. Legs long with prominent claws.

Body smooth and finely shagreened, but less shining than in the workers and female; mesonotum decidedly opaque. Mandibles shagreened, with a few large punctures along their outer edges. Cheeks and occiput sparsely and coarsely punctate or foveolate.

Pilosity scarse, as in the worker. Hairs on the gastric segments more scattered and irregular in their arrangement, long and prominent on the terminal segments. Antennal scape with a few long hairs at the tip.

Head black; mouth, mandibles, clypeus, and cheeks, and in some specimens also the front, yellowish red. Color of thorax as in the female, except that the three elongate black blotches on the mesonotum are more distihct. Petiole red, more or less clouded with black. Gaster black, genitalia and posterior edges of segments yellow. Wings like those of the female. Legs and antennae yellowish red.

References based on Global Ant Biodiversity Informatics

 * Cokendolpher J. C., and O. F. Francke. 1990. The ants (Hymenoptera, Formicidae) of western Texas. Part II. Subfamilies Ecitoninae, Ponerinae, Pseudomyrmecinae, Dolichoderinae, and Formicinae. Special Publications, the Museum. Texas Tech University 30:1-76.
 * Cokendolpher J.C., Reddell J.R., Taylor S.J, Krejca J.K., Suarez A.V. and Pekins C.E. 2009. Further ants (Hymenoptera: Formicidae) from caves of Texas [Hormigas (Hymenoptera: Formicdae) adicionales de cuevas de Texas]. Texas Memorial Museum Speleological Monographs, 7. Studies on the cave and endogean fauna of North America, V. Pp. 151-168
 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Longino, J.T. 2010. Personal Communication. Longino Collection Database
 * Morrison, L.W. 2002. Long-Term Impacts of an Arthropod-Community Invasion by the Imported Fire Ant, Solenopsis invicta. Ecology 83(8):2337-2345
 * O'Keefe S. T., J. L. Cook, T. Dudek, D. F. Wunneburger, M. D. Guzman, R. N. Coulson, and S. B. Vinson. 2000. The Distribution of Texas Ants. The Southwestern Entomologist 22: 1-92.
 * Reddell J. R., and J. C. Cokendolpher. 2001. Ants (Hymenoptera: Formicidae) from caves of Belize, Mexico, and California and Texas (U.S.A.) Texas. Texas Memorial Museum Speleological Monographs 5: 129-154.
 * Smith M. R. 1936. A list of the ants of Texas. Journal of the New York Entomological Society 44: 155-170.
 * Van Pelt, A. 1983. Ants of the Chisos Mountains, Texas (Hymenoptera: Formicidae) . Southwestern Naturalist 28:137-142.
 * Wheeler W. M. 1903. A decad of Texan Formicidae. Psyche (Cambridge). 10: 93-111.
 * Wheeler W. M. 1910. The North American ants of the genus Camponotus Mayr. Annals of the New York Academy of Sciences 20: 295-354.
 * Wheeler W. M. 1917. The mountain ants of western North America. Proceedings of the American Academy of Arts and Sciences 52: 457-569.
 * Wheeler, G.C. and J. Wheeler. 1985. A checklist of Texas ants. Prairie Naturalist 17:49-64.