Temnothorax subditivus

(Wheeler 1931) I have taken this species nesting, like certain species of Temnothorax, in the bark of large trees (willows) at Austin, Del Valle, and New Braunfels, Texas, and have specimens taken by J. A. Mitchell at Victoria and by R. A. Vickery at Harlingen, in the same state.

Identification
(Smith 1939) The worker of Temnothorax subditiva can be readily distinguished by the peculiarly shaped petiole, the peduncle of which is at least twice the length of the petiolar node; the rather uniform brownish color of most of the body; the obsolescent or missing thoracic sutures; the slender antennal scapes; and the sculpturing of the body.

Range
USA, MEXICO. Texas and areas adjacent to TX border in Mexico.

Taxonomy
Macromischa subditiva Wheeler, W.M. 1903b: 99, fig. 5 (w.) U.S.A. Wheeler, W.M. 1931b: 15 (q.); Smith, M.R. 1939e: 504 (m.). Combination in Leptothorax: Baroni Urbani, 1978b: 512; in Temnothorax: Bolton, 2003: 272. Senior synonym of flavitarsis, laevissima, luciliae: Baroni Urbani, 1978b: 512. See also: Creighton, 1966a: 282.

Worker
Length 2-2.5 ram. Head somewhat longer than broad, rounded at the posterior angles and convex above. Mandibles rather small, with three acute apical and three much smaller basal teeth. Clypeus short, broadly rounded in front, convex in the middle, with a prominent median carina running its full length and continued over the frontal area. Frontal area large, triangular, longer than broad. Antennae long, 12-jointed; scape extending beyond the posterior corner of the head to a distance equal to twice its breadth; first funicular joint nearly as long as the three succeeding joints together, joints 2-8 about as long as broad, two penultimate joints subequal, together as long as the terminal joint. Thorax short and thick-set, dorsum in profile convex, evenly rounded prothorax with broadly rounded angles, promesonotal suture very faintly, mesopinotal suture somewhat more distinctly indicated. Epinotum armed with two stout spines, which are very close together at their bases but diverge strongly outward, upward, and backward; epinotal declivity concave. Petiole long, with a conspicuously elongated peduncle which passes very abruptly into the transverse node; the latter is much compressed antero-posteriorly when seen in profile, the anterior and posterior surfaces being flattened and perpendicular, the summit of the node narrow and rounded when seen from behind, the edge of the node is horizontal and nearly straight. There is a small but distinct tooth on the ventral surface of the petiole near its anterior end. Postpetiole from above but little wider than the node of the petiole, fully twice as broad as long, rounded oblong; in profile it is nodiform, very convex dorsally, in both views showing a decided constriction at its insertion into the gaster. Gaster of the usual shape, with a long, powerful sting. Legs of the usual shape, with the femora conspicuously incrassated in the middle. There are no spurs on the middle and hind tibiae.

Head, including the mandibles and clypeus, subopaque, sharply longitudinally rugose; the rugae connected by subsidiary reticulate rugae on the base of the mandibles, cheeks, and sides of the head. Clypeus and frontal area more shining, the former with few rugae, especially near the middle. Thoracic dorsum shining, pleurae and epinoturn subopaque. Whole surface of thorax reticulate rugose, regularly in the opaque regions, more irregularly and more longitudinally on the shining dorsal surface. Petiole and postpetiole shining above, reticulate and subopaque on the ventral and lateral surfaces. Gaster very smooth and shining. Legs more opaque, finely but distinctly reticulate.

Head, thorax, and abdomen beset with sparse, erect, obtuse, silvery white hairs; antennae and legs with minute, appressed, pointed hairs of the same color.

Body black or, in immature specimens, very dark brown mandibles, antennae, legs and epinotal spines, tip of gaster, and sting yellow, scape and club of antennae, bases of epinotal spines, and greater portion of femora and tibiae infuscated.

Queen
(Wheeler 1931) 3.5 mm. Head subrectangular, as broad as long, broader behind than in front, with convex posterior border. Thorax less than twice as long as broad, mesonotum nearly as broad as long, flattened above; scutellum nearly as long as the epinotum, which is short, with sloping base and vertical declivity; spines acute, stout at base, shorter than their distance apart. Postpetiole nearly 2! times as broad as long; gaster large, elliptical, with concave anterior border. Pilosity and coloration as in the worker, head and thorax more opaque, evenly longitudinally rugulose.

Male
(Smith 1939) Length 2.2 mm. Head, exclusive of mandibles, approximately as broad as long, with strongly convex posterior border, and moderately convex sides. Eye extremely large, convex, occupying at least half length of side of head, its anterior border almost touching base of mandible. Clypeus convex. Mandible small, toothed. Postocellar line longer than lateral ocellar line. Antenna slender, 13-segmented, the last 3 segments considerable enlarged. Thorax without Mayrian furrows, but with faint parapsidal furrows. Scutellum strongly gibbous. Epinotum without spines or tubercles. Wings pale, translucent, with very faint veins; discoidal, cubital, and radial cells lacking, but stigma well developed. Legs rather long and slender, femora not incrassate. In profile, peduncle of petiole noticeably short, its dorsal surface forming a gradually ascending slope, which meets the somewhat flattened posterior surface of the node to form a bluntly angular, but low node. Postpetiole from above transversely elliptical, wider than long, but not much wider than petiole. Gaster with basal angles.

Hairs grayish, short, erect, sparse; more abundant on gaster, especially toward apex. Pilosity sparse, appressed; most easily discernible on appendages.

Brown; appendages lighter; apices of coxae, trochanters, bases of femora, and tarsi even lighter.