Temnothorax annexus

Wheeler (1931) reports this species was collected from the epiphytic plant Tillandsia circinnata.

Identification
Wheeler (1931) - This singular ant somewhat resembles M. azteca and salvini, but is really very different. In habitus it is so much like certain species of Leptothorax, especially those of the rottenbergi group, that I should have placed it in that genus but for its more conspicuously incrassated femora.

Distribution based on Regional Taxon Lists
Neotropical Region: Mexico.

Nomenclature

 * annectens. Macromischa annectens Wheeler, W.M. 1931b: 11 (w.) MEXICO. [Junior secondary homonym of annectens Wheeler, W.M., above.] Replacement name: annexus Baroni Urbani, 1978b: 421.
 *  annexus. Leptothorax annexus Baroni Urbani, 1978b: 421. Replacement name for annectens Wheeler, W.M. 1931b: 11. [Junior secondary homonym of annectens Wheeler, W.M. 1903c: 242.] Combination in Temnothorax: Bolton, 2003: 271.

Worker
(Wheeler, 1931; annectens) Length about 3.7 mm.

Head subrectangular, slightly broader behind than in front, with broadly rounded posterior corners and nearly straight posterior border. Eyes moderately large and convex, at the middle of the sides. Mandibles rather small and flat, with a large apical and four smaller basal teeth. Clypeus short, convex in the middle behind, its anterior border sinuate in the middle and on each side so that it appears somewhat bilobed. Frontal area triangular, rather indistinct. Frontal carinae short, diverging posteriorly. Antennal scapes reaching to the posterior corners of the head; first funicular joint as long as the three succeeding joints together; joints 2-7 small, broader than long, 8 as long as broad; the three terminal joints forming a very distinct club, as long as the remainder of the funiculus and with the two basal joints subequal and together shorter than the last joint. Thorax long and narrow, fully three times as long as broad, somewhat broader through the pronotum than through the parallel-sided mesoepinotum; pleurae flattened; dorsal surface in profile nearly straight and horizontal, without mesoepinotal impression; base and declivity of epinotum subequal, the latter perpendicular and concave; the spines stout at the base, laterally compressed, with blunt tips, longer than their distance apart at the base, but shorter than the epinotal declivity, directed backward and outward and very slightly curved downward. Peduncle of petiole with a minute anteroventral tooth, nearly as long as the node, which is somewhat cuboidal and constricted behind, in profile with steeply sloping anterior, horizontal superior and perpendicular posterior surface; seen from above, it is as long as broad, semicircularly rounded anteriorly, with straight posterior border. Postpetiole l 2/3 times as broad as the petiolar node and about 1 1/2 times as broad as long, rounded-trapezoidal, slightly broader behind than in front, convex and rounded above. Gaster 'rather large, broadly elliptical, first segment with truncated, nearly straight anterior border; sting long. Legs stout; all the femora, and especially the hind pair, conspicuously incrassated in the middle.

Opaque; venter, coxae, legs and antennal scapes feebly shining, or glossy. Mandibles finely longitudinally striated. Clypeus longitudinally rugulose, most distinctly on the sides. Head densely punctate above, longitudinally reticulate-rugose, its sides and the sides of the thorax merely reticulate-rugose, the dorsal surface of the latter longitudinally but more vermiculately rugose, the pronotum much more coarsely than the mesoepinotum. Epinotal declivity smooth but dull. Petiolar node indistinctly reticulate-rugose above, postpetiole coarsely and densely, and dorsal surface of first gastric segment more distinctly, scapes and legs more finely and indistinctly reticulate or shagreened.

Hairs on the body yellowish, short, stout and obtuse (as in Leptothorax), not very abundant and confined largely to the dorsal surface; pubescence very short and appressed, distinct on the antennae, almost absent on the legs.

Ferruginous red; mandibles, antennae, coxae, legs, petiolar peduncle and terminal gastric segments paler, dull ferruginous yellow; first gastric segment with a poorly defined dark brown fascia posteriorly. Mandibular teeth black.

Type Material
Described from three specimens taken by Dr. Skwarra at Cuernavaca, Morelos, Mexico, nesting in an air-plant, Tillandsia circinnata.

References based on Global Ant Biodiversity Informatics

 * Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
 * Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
 * Vásquez-Bolaños M. 2011. Lista de especies de hormigas (Hymenoptera: Formicidae) para México. Dugesiana 18: 95-133