Trachymyrmex Jamaicensis

Mayhé-Nunes, A. J. & Brandão, C. R. F., 2007, Revisionary studies on the attine ant genus Trachymyrmex Forel. Part 3: The Jamaicensis group (Hymenoptera: Formicidae)., Zootaxa 1444, pp. 1-21 : 3-4

Taxonomic account

Trachymyrmex Jamaicensis species group

(Figs. 1-30)

Diagnosis: Monomorphic attine ants with the antennal scrobe margins always reaching and even surpassing the posterior margin of the head; frontal and preocular carinae well marked, subparallel throughout their whole extension, limiting the impressed antennal scrobe; extremities of frontal and preocular carinae always separate and with up to three triangular or rounded compressed tubercles or vertical teeth close to the posterior margin (figs 1, 5, 9, 13, 15, 19, 23, 27); preocular carina not curved mesad above eyes. Frontal lobes from moderately approximate to moderately expanded laterad, but in most species the interfrontal width near 2/3 of the head width across the eyes (FLI 50-70). Occipital projections (teeth or spines) always present on head. Posterior margin in full-face view smoothly concave, notched in the middle. The paired vertexal carinae indicated by a series of weakly connected piligerous denticles, flanking the shallowly impressed sagital furrow, which in front joins the transverse impression of frons, behind the frontal area. Outer border of mandibles sinuous. Mandibles with discal area smooth and shining, the fine striae confined to the mandibular bases and sides. All funicular segments, including 2nd, longer than broad.

Key to Trachymyrmex of the Jamaicensis species group (workers)

1 With the body in side view, length of lateral pronotal and anterior mesonotal projections notably different, either the mesonotal is much bigger than pronotal (Fig. 10), or appears as a multitubercular low tumulus (Fig. 16) ......................................................................................................................................................2

- Lateral pronotal and anterior mesonotal projections almost of the same size or the mesonotal a little shorter, but always spine-like......................................................................................................................3

2 Lateral pronotal spine-like projections shorter and slenderer than anterior mesonotal ones; midpronotal projections present; pronotal inferior corner and anterior margin of katepisternum unarmed; postpetiole in dorsal view trapezoidal, little broader behind than in front, its postero-dorsal border straight.................... ............................................................................................................ T. isthmicus Santschi (Figs 9-14, 30)

- Lateral pronotal spine-like projections longer than tumuliform and multituberculated anterior mesonotal ones; midpronotal projections absent or obsolete; pronotal inferior corner and anterior margin of upper region of katepisternum armed with a notable triangular tooth; postpetiole in dorsal view broader than long, its posterior border concave............................................................ T. ixyodus n. sp. (Figs. 15-18, 30)

3 Apically spatulate curved coarse hairs distributed over the whole body (Figs. 3, 26) ...............................4

- Curved coarse hairs apically spatulate absent over the whole body, except gaster....................................5

4 Antennal scape scarcely surpassing the posterior margin of head when lodged in the scrobe, with head in frontal view; anterior margin of the crenate frontal lobe with a protruded pointed tooth; propodeal spines distinctly longer than the distance between their inner bases (better seen in postero-dorsal view).............. ................................................................................................................... T. zeteki Weber (Figs 23-26, 30)

- Antennal scape surpassing the posterior margin by nearly a third of its length, when lodged in the scrobe, with head in frontal view; anterior margin of the smooth frontal lobe unarmed; propodeal spines distinctly shorter than the distance between their inner bases (better seen in postero-dorsal view)............................. .................................................................................................................. T. atlanticus n. sp. (Figs 1-5, 30)

5 Base of the anterior mesonotal spine thicker than the base of lateral pronotal ones; midpronotal projections absent or rarely represented by a pair of minute separate spines; supraocular projection spine-like; head and gaster darker than yellowish brown mesosoma; last funicular segments as dark as antennal scapes............................................................................................. T. jamaicensis ( Andre) (Figs 19-22, 29)

- Base of the anterior mesonotal spine almost as thin as the base of lateral pronotal ones; midpronotal projection represented by a single truncate tooth; supraocular projection absent or vestigial; the whole body dark reddish brown; last funicular segments lighter than other antennal segments ..................................... ............................................................................................... T. haytianus Wheeler & Mann (Figs 5-8, 29)