Probolomyrmex lamellatus New species

(Figs. 24, 25)

Holotype: BRAZIL: Pará: Terra Santa, FLONA, Saracá-Taquera, Base Patauá, 1°51’27.23”S 56°27’48.4”W, 70m, 25–29.viii.2016, R.M. Feitosa, E.Z. Albuquerque, R. Silva col, Winkler (worker) [DZUP, unique specimen identifier DZUP 549767].

Diagnosis: Propodeum and petiole entirely emarginated posteriorly by a conspicuous lamella, without teeth. Postero-ventral lobe of petiole short and subquadrate. Subpetiolar process weakly developed. Prora weekly developed and dorsal protuberance on the posterior region of the first gastral tergite weakly developed.

Worker measurements: (n=1) HL 0.50; HW 0.30; SL 0.30; WL 0.59; PL 0.30; PW 0.24; PH 0.20; TL 2.11; CI 59.3; SI 59.3; PI 78.5.

Worker description: Frontoclypeal shelflike projection micropunctate; mandibles foveated; external surface of mandibular basal margin large and imbricated (Fig. 24B – esm). Antennal funiculi with pits; tip of apical segment of antennae bearing different sized pits (Fig. 24C – Ap). Mesopleuron foveate and micropunctate; metapleuron alveolate and foveated; lateral faces of propodeum foveated and micropunctate; alveoli denser just above metapleural gland orifice; opening of metapleural gland large, with smooth anterior region, surrounded by rows of hairs (Fig. 24D). Petiolar node and postero-ventral lobe of petiole with incomplete foveae and micropunctures; latero-ventral region of petiole and subpetiolar process alveolate (Fig. 24E). Posterior region of second gastral tergite with transversal rows of deep rounded pits.

Space between mesosomal foveae covered by dense pubescence.

Head 1.8 times longer than wide (Fig. 25B). Hypostomal margin curved (Fig. 24B – he). Antennal scapes extend to head midlength, distance from scape apex to of head more than two times pedicel length (SI 59.3). Propodeum and petiole entirely emarginated posteriorly by a dark lamella, without teeth (Fig. 25A); Petiole 1.5 times longer than high (PI 78.5) posterior face short, straight, and smooth; postero-ventral lobe short and subquadrate; subpetiolar process weakly developed (Fig. 24E). First gastral segment with weakly developed prora and dorsal protuberance on posterior region of tergite weakly developed (Figs. 24A, 25A).

Etymology: The epithet refers to the posterior lamella of the propodeum and petiole, an exclusive characteristic of this species.

Distribution (Fig. 29): Brazil (PA).

Comments: Probolomyrmex lamellatus is similar to P. cegua, but the head is comparatively longer, the propodeum and petiole are unarmed and completely emarginated by a dark lamella, and the postero-ventral lobe of petiole is subquadrate. The single known specimen came from a leaf-litter sample collected at in mature lowland Amazon forest.