Pseudomyrmex veracruzensis

Pseudomyrmex veracruzensis is known only from two adjacent sites in the Sierra de los Tuxtlas, Veracruz. Collections include two nest series from dead twigs of Heliocarpus, and isolated workers foraging on low vegetation, all at the edge of montane rainforest (1,010 m–1,055 m).

Identification
Medium-sized species (HW 0.97–1.07) with moderately elongate head (CI 0.81–0.86) and eyes (REL 0.46–0.48); frontal carinae separated by less than basal scape width; metanotal groove moderately impressed, evident in proﬁle; dorsal face of propodeum more or less ﬂat, rounding into declivitous face, the two subequal in length; petiole slender, elongate (PLI 0.44–0.49, PL/HL 0.57–0.60, PL/LHT 0.76–0.82); petiole with slight anterior peduncle, in proﬁle the anterodorsal face ﬂat to convex, ascending gradually to summit in posterior half of node, then rounding into more steeply descending posterior face; profemur relatively slender (FI 0.42–0.45); hind leg relatively short (LHT/HL 0.71–0.76). Head subopaque, densely punctulate-coriarious, the punctures becoming less dense on vertex (separated by their diameters or more). Standing pilosity sparse, absent from propodeum and mesonotum (MSC 2–5). Medium ferrugineus-brown, with darker and rather diffuse transverse bands on anterior half of abdominal tergites 4–6 (gastric tergites 1–3); metafemur and, to a lesser extent, mesofemur infuscated.

Key features of this species are the ferrugineus-brown body, with darker transverse bands on the gaster; relatively large size (worker HW 0.97–1.07); and low, elongate petiole (worker PL 0.65–0.77, worker PLI 0.44–0.49). Workers of P. veracruzensis are superﬁcially similar to those of the Costa Rican species, Pseudomyrmex nimbus, but can be distinguished by their shorter legs (LHT 0.84–0.94 and LHT/HL 0.71–0.76 vs LHT 0.96–1.09 and LHT/HL 0.76–0.82 in P. nimbus), smaller eyes (REL 0.46–0.48 vs 0.48–0.51 in P. nimbus), less strongly impressed metanotal groove, differently shaped petiole (compare Figs. 16 and 18), and lighter coloration. An index combining PL, LHT and HW also separates the two species: (PL/ LHT)/HW 0.74–0.80 versus 0.62–0.71 in Pseudomyrmex nimbus. P. veracruzensis is somewhat isolated phylogenetically, as sister to (Pseudomyrmex nimbus, (Pseudomyrmex exoratus (Pseudomyrmex ereptor, Pseudomyrmex elongatulus))) (Fig. 1).

Distribution based on Regional Taxon Lists
Neotropical Region: Mexico.

Nomenclature

 * . Pseudomyrmex veracruzensis Ward & Branstetter, 2022: 27, figs. 18, 26 (w.) MEXICO (Veracruz).

Type Material

 * Holotype Worker. MEXICO Veracruz: Ruiz Cortínez, 13 km NE San Andrés Tuxtla, 1,055 m, 18.53387 –95.13839 ± 4 m, 5 Jun 2016, ex dead twig of Heliocarpus, montane rainforest edge, P. S. Ward PSW17618 (UNAM) (CASENT0863542).
 * Paratypes: series of workers, same data as holotype (CASC, CZUG, IEXA, JTLC, MCZC, PSWC, UCDC, USNM).