Adelomyrmex longinodus Fernandez & Brandao, 2003

Fernández, F., 2003, Revision of the myrmicine ants of the Adelomyrmex genus-group (Hymenoptera: Formicidae)., Zootaxa 361, pp. 1-52 : 20-21

Adelomyrmex longinodus Fernandez & Brandao NEW SPECIES (Figs. 57-61, 64, 74)

Worker measurements (Paratypes= 4). HL 0.55-0.57 HW 0.50-0.52 SL 0.36-0.37 EL 0.04 -0.05 WL 0.63-0.67 GL 0.50-0.55 TL 2.30-2.44 CI 90-91 SI 71-72.

Worker diagnosis: Head with convex posterior and evenly rounded corners. Hypostomal bridge strong and evenly developed; very much distinct from head venter. Hypostomal teeth absent. Sides of head slightly concave before the eyes, slightly convex past eyes. Mandibles with 4 teeth decreasing in size from the apical teeth, the antepenultimate (subbasal) smallest. Mandibles with tooth in their basal margin, not followed by a notch. Palp formula 1,2. Maxillary palpomere subcylindrical and the labial palps geniculate; the apical segment much enlarged and globose. Eyes lenses absent, although the pigments are clearly visible under the reflective light, but not under the SEM picture. Clypeus short, elevated in the middle as a narrow stripe, pointed and fused with frontal carinae. Anterior margin of the clypeus without teeth, although with feebly projections instead. Dorsal view of thorax as in Fig. 60. From above, the promesonotum is heart shaped, ending in a triangular mesonotum. Pronotal humeri very broadly rounded in dorsal view, the dorsal alitrunk pinched in at the metanotal line. Propodeum spiracle relatively large, its orifice circular and situated just above the midlength of the sclerite; propodeum dorsum straight, meeting declivity in sharp diverging teeth, gently curved inwards when seen from above; declivity smooth, the metapleural lobes not joined over the foramen. Opening of the metapleural gland indistinct (Fig. 61). Petiole with a short anterior peduncle, lacking an anteroventral process; petiolar node subquadrate, dorsally broadly convex in profile untill it approaches the postpetiole where it ends abruptly in a right angle. Postpetiole low and small, gently convex in profile, in dorsal view very broadly attached to the gaster (Fig. 61). In profile the postpetiole articulated medially on the first gastral segment. Sting large and strongly sclerotized, disproportionately powerful. Head, most of promesonotum, sides of pronotum and gaster smooth and shining; propodeal triangle and sides of petiole and postpetiole with coarse rugae more or less longitudinal on petiole and postpetiole. Posterior face of propodeum deep, smooth and shining. Petiole with rugulae concentric around node, dorsally transverse and longitudinal on sides; sides of postpetiole with oblique rugulae, smooth and shining in the top, mandibles smooth and shining. Abundant fine hairs long and flexuous on body, shorter and appressed on antennae and legs. Body dark brown (including hairs), antennae and legs lighter.

Queen measurements. Paratype. HL 0.54 HW 0.51 SL 0.22 WL 0.66.

Larger, but not very much, than conspecific worker. Compound eyes with several facets over the largest diameter. Otherwise description as worker.

Male: Unknown.

Holotype worker: BRASIL: Amazonas, near Manaus , 1.iii. 94, R. Didham leg. (deposited in BMNH).

Paratypes: 7 paratype w, same data as holotype, deposited in BMNH, MCZ, MZSP, ICN, PSW. 1 paratype q and 6 paratype w, BRAZIL: Amazonas, Manaus, Shift 52, Floresta Berlese funnel No. 04, 03.iii. 98, M. García et al. leg., deposited as follow: 1 worker in INPA, 3 workers (2 coated with gold) and dealated queen in MZSP, 1 worker in IAvH, 1 worker in SMNK. 1 worker, BRAZIL: Amazonas, Manaus , Rs 3114 20 , i.1994 A.B. Casimiro (Deposited in CEPLAC). 1 worker, BRAZIL: Espiritu Santo, Linhares , 7.vii.1994, A.B. Casimiro No. 4869 (Deposited in CEPLAC).

Comments. This very interesting species is similar to A. boltoni . Both have several morphological traits that differ from other known Adelomyrmex species. At first glance, these could be sufficient to merit generic status, and both species were separated from other Adelomyrmex species in BMNH.

The MZSP specimens (Brazil: Manaus) were collected from soil samples in a locality whose ant fauna is otherwise well-known. No other specimen of this rather distinctive species has ever been collected by traditional techniques. Subterranean ants may be far more common than previously imagined, perhaps with a heretofore-unsuspected fauna awaiting description.

A. longinodus can be separated from A. boltoni by lack of sculpturing on the sides of the thorax (longitudinal rugulae in boltoni ).