Eurhopalothrix hunhau

This species occurs in mature cloud forest and wet oak/pine forests in the mountains of southern Mexico and Guatemala, from 1000–2000 m elevation. Most collections are from Winkler or Berlese samples of sifted leaf litter and rotten wood. A worker was collected as an isolated ground forager, and another worker was collected at or near a bait on the ground. It can be locally abundant: on the slopes of Volcán Atitlán in Guatemala it occurred in 35% of quantitative miniWinkler samples. (Longino 2013)

Identification
Masticatory margin of mandible with double row of teeth, outer series of lower triangular teeth, inner row of 3 long, spiniform teeth; erect setae on face strongly spatulate; basal lobe of scape strongly developed, SLI 15–21; HW 0.69–0.83; posterior mesonotum with a pronounced, short longitudinal keel between the posteriormost pair of spatulate setae. Similar to Eurhopalothrix gravis, Eurhopalothrix xibalba. (Longino 2013)

Distribution
Mexico (Chiapas), Guatemala.

Distribution based on Regional Taxon Lists
Neotropical Region: Guatemala, Honduras, Mexico.

Nomenclature

 *  hunhau. Eurhopalothrix hunhau Longino, 2013: 123, figs. 10B, 21, 35 (w.) GUATEMALA.

Worker
HW 0.69–0.83, HL 0.68–0.82, SL 0.41–0.48, SLL 0.07–0.10, CI 101–108, SLI 15–21 (n=8). Labrum longer than broad, anterolateral gibbosities of basal portion developed as short, ventrally-directed teeth, apical portion of labrum elongate, in approximately same plane as basal portion (not flexed dorsally), distinctly bilobed with elongate, bluntly triangular lobes; lobes with fringe of translucent setae, apical setae capitate; mandible triangular, dorsal surface convex, roughened, dull, rounding into ventral surface; interior surface concave, smooth and shining; masticatory margin with two tooth rows, an outer row of 10 teeth and an inner row of 3 long needle-shaped teeth, behind outer teeth 3–6 and projecting beyond them, nearly 2x length of flanking outer teeth; tooth 1 of outer row broader than others; tooth 2 long and acute; teeth 3–6 low, acute; teeth 7 and 10 long and sharp, similar to teeth of inner row; teeth 8–9 shorter; scape with strongly developed basal lobe, dorsal surface roughened; scrobe deep, sharply delimited dorsally and ventrally, abutting deep antennal socket; surface of scrobe foveolate; eye with about 6 ommatidia across greatest diameter; clypeus convex posteromedially, sloping to slightly concave anterior apron, anterior margin with broad, semicircular emargination; posterior portion roughened, grading to more smooth and shining anteriorly; juncture of clypeus and frons impressed; sides of head above eyes moderately angulate; surface of face uniformly convex, confluently punctate posteriorly, grading to punctatorugose anteriorly, anterior frons with well-developed longitudinal medial carina; occipital carina strongly developed and sharp dorsally, obsolete laterally; undersurface of head punctate posteriorly, punctatorugose anteriorly; postgenal suture a well-developed longitudinal trough.

Promesonotal profile evenly convex to somewhat flat-topped, posterior portion abruptly elevated by a short, sharp, longitudinal keel between the posteriormost pair of spatulate setae; metanotal groove a broad U-shaped impression, anterior border of dorsal face of propodeum delimited with distinct, raised rim; dorsal and posterior faces of propodeum distinct, meeting at obtuse angle, dorsal face shorter than posterior face; propodeal spine triangular, acute, ventral margin curving into narrow infradental lamella that extends down posterior face to propodeal lobe; propodeal spiracle relatively large, directed posteriorly; dorsal promesonotum punctatorugose; anterior and lateral pronotum, mesopleuron, lateral propodeum, dorsal and posterior faces of propodeum punctate; bulla of metapleural gland smooth, matte; without transverse carinulae between propodeal spines.

Petiolar peduncle joins anterior face of petiolar node at obtuse angle; petiolar node subquadrate, anterior face meeting dorsal face at rounded right angle; low transverse carina separates dorsal face and short, concave posterior face; ventral margin of petiole with acute anteroventral tooth; postpetiole low and broad, with a shallow longitudinal sulcus dorsally; first gastral sternite lacking anterior sagittal keel; petiole, postpetiole, first gastral tergite covered with dense, small, puncta, interspaces less than or equal to width of puncta; first gastral sternite similar, but puncta and interspaces larger.

Dorsal surface of scape uniformly covered with short, decumbent, spatulate setae; leading edge of scape with projecting setae, shortest near apex, gradually lengthening to longest on basal lobe; ground pilosity of face comprising spatulate decumbent setae densely distributed on posterolateral vertex lobes, across anterior frons, and onto frontal lobes; ground pilosity very sparse on medial frons and vertex; ground pilosity on clypeus smaller, more appressed, longitudinally-oriented, densely and evenly distributed; projecting specialized setae strongly spatulate to pompon-like, about 2x longer than wide, much larger than ground pilosity and highly differentiated from it, full complement 18, with curved anterior row of 8, transverse median row of 4, and posterior row of 6 on vertex margin; very sparse ground pilosity of small flattened setae on promesonotal dorsum, dorsal petiolar node, first gastral tergite, denser on dorsal postpetiole; 3 pairs projecting spatulate setae on promesonotum; legs with dense, strongly flattened, appressed to decumbent setae on apices of femora, posterior face of foretibia, entire midtibia, anterior face of hindtibia, somewhat sparser on other surfaces; apices of fore, mid and hind tibia with 1–2 larger spatulate seta; basitarsus and remaining tarsomeres with abundant, spatulate setae; two large spatulate setae on hind margin of dorsal face of petiolar node; row of 4 spatulate setae on hind margin of postpetiole; specialized setae of first gastral tergite spatulate, full complement 16–20, more or less evenly distributed over entire tergite.

Color dark brown.

Queen
HW 0.79, HL 0.75, SL 0.45, SLL 0.09, CI 105, SLI 20 (n=1). Similar to worker in most respects; ocelli present; compound eye much larger than worker eye; anepisternum separated from katepisternum by broad groove; metapleuron separated from propodeum by broad groove; pronotum punctate; anepisternum and katepisternum punctate, puncta smaller and sparser anteriorly; side of propodeum punctate; bulla of metapleural gland smooth and matte; mesoscutum and scutellum punctatorugose; axilla separated from scutellum by broad transverse trough with coarse longitudinal rugae; pronotum with 7 spatulate setae on single observed queen; mesoscutum with 6 setae, 4 peripheral setae spatulate, medial 2 smaller, more clavate; axilla with spatulate seta; scutellum with 1 pair spatulate setae; first gastral tergite with number and arrangement of erect setae similar to worker.

Type Material
Holotype worker: Guatemala, Zacapa: 2km SE La Unión, 14.94681 -89.27583, ±50 m, 1550 m, 12 May 2009, cloud forest, ex sifted leaf litter (LLAMA Wa-B-03-1-08), unique specimen identifier CASENT0614549. Paratype workers: same data as holotype, CASENT0614548; same data but 14.95320 -89.27559, ±50 m, 1430 m (LLAMA Wa-B-03-2-48) , CASENT0612539; , CASENT0612540; , CASENT0612541; same data but 14.94654 -89.27600, ±55 m, 1550 m, 2º cloud forest, ex sifted leaf litter (LLAMA Wm-B-03-1-01) UVGC, CASENT0612544; , CASENT0612551; same data but 14.94460 -89.27726, ±57 m, 1550 m, cloud forest, ex sifted leaf litter (LLAMA Wm-B-03-1-05) , CASENT0612562; , CASENT0612566.

Etymology
Hunhau was a primary Mayan death god, lord of the underworld. It is a noun in apposition and thus invariant.

References based on Global Ant Biodiversity Informatics

 * Dattilo W. et al. 2019. MEXICO ANTS: incidence and abundance along the Nearctic-Neotropical interface. Ecology https://doi.org/10.1002/ecy.2944
 * Longino J. T. 2013. A review of the Central American and Caribbean species of the ant genus Eurhopalothrix Brown and Kempf, 1961 (Hymenoptera, Formicidae), with a key to New World species. Zootaxa 3693(2): 101-151.
 * Longino J. T. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.