Probolomyrmex dentinodis

All known specimens of this species were obtained from leaf-litter samples collected in mature lowland Amazon forests (40m and 200m).

Identification
Oliveira & Feitosa (2019) - Petiole higher than long, with the petiolar teeth well developed and forming a conspicuous posterior bifurcation in dorsal view. Subpetiolar process well developed and subrectangular. Prora present. First gastral tergite with a dorsal protuberance on the posterior region.

The subrectangular shape of the subpetiolar process makes this species similar to Probolomyrmex petiolatus. However, P. dentinodis can be easily distinguished from the latter by the presence of a pair of propodeal and petiolar teeth and by the presence of the prora.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  dentinodis. Probolomyrmex dentinodis Oliveira & Feitosa, 2019: 78, figs. 16-18 (w.q.) BRAZIL.

Worker
(n=8): HL 0.57–0.61; HW 0.35–0.39; SL 0.36–0.44; WL 0.74–0.89; PL 0.23–0.30; PW 0.15–0.19; PH 0.26–0.33; GL 0.94–0.96; TL 2.63–2.74; CI 61.5–64.5; SI 61.5–73.5; PI 106.5–128.5.

Frontoclypeal shelflike projection and mandibles with hair-bearing tubercles or cylindrical micro-pegs; external surface of mandibular basal margin transversely micro-striate. Tip of apical segment of antennae bearing minute pits. Mesopleuron, metapleuron and lateral faces of propodeum alveolate; alveoli denser just above metapleural gland orifice; opening of metapleural gland large, with smooth anterior region, surrounded by rows of hairs. Petiolar node with incomplete foveae, postero-ventral lobe of petiole and subpetiolar process alveolate, each alveolus with an inner decumbent hair; latero-ventral region of petiole imbricate. Posterior region of second gastral tergite with transversal rows of deep rounded pits. Space between the foveae on the mesosoma covered by dense pubescence. Pygidium with hair-bearing tubercles or cylindrical micro-pegs and some long and thick hairs. Head 1.6 times longer than wide. Hypostomal margin curved. Antennal scapes extend to head midlength, distance from scape apex of head more than two times pedicel length (SI 61.5–73.5). Propodeum emarginated posteriorly on each side by a low and obtuse carina, with teeth at their apexes. Petiole at least 1.1 times higher than long (PI 106.5–128.5), with postero-dorsal teeth forming a conspicuous bifurcation in dorsal view; posterior face long, concave and smooth; postero-ventral lobe short and rounded; subpetiolar process well developed and subrectangular, with the postero-ventral angle acute and directed towards the gaster. First gastral segment with prora and a dorsal protuberance on posterior region of tergite, characterized by a gentle elevation of the integument.

Queen
(n=2): HL 0.59–0.62; HW 0.39; SL 0.39–0.42. WL 0.80–0.87; PL 0.26–0.28; PH 0.30–0.32 GL 0.96–1.07; TL 2.61–2.84. CI 62–65; SI 65–67; PI 114–116.

Queen presents the characters already described in the genus description and the diagnostic characters of the species.

Type Material

 * Holotype: BRAZIL: Rondônia: Porto Velho, Área Caiçara, 09°26’14.6”S 64°49’58.2”W, 04–18.ix.2012, Vicente R.E. & Oliveira J. cols, C1P2, (worker) [DZUP, unique specimen identifier DZUP 549762].
 * Paratype: same data as holotype, except: (1 worker) [MZSP, unique specimen identifier DZUP 549769].

Etymology
The name is a reference to the presence of a pair of well developed postero-dorsal teeth on the petiolar node.

References based on Global Ant Biodiversity Informatics

 * Oliveira A. M., and R. M. Feitosa. 2019. Taxonomic revision of the genus Probolomyrmex Mayr, 1901 (Hymenoptera: Formicidae: Proceratiinae) for the Neotropical Region. Zootaxa 4614: 61–94.