Stenamma llama

Stenamma llama is a cloud forest specialist occurring from approximately 1100 m to 1600 m elevation. All specimens are known from sifted leaf litter collected from the forest floor, except for one, which was found at a cookie bait card. It is a rare species currently known from only one site in Oaxaca, Mexico, and one site in Guatemala. At the Guatemala site, out of 100 mini-Winkler and six maxi-Winkler samples, only six specimens were collected. The completely smooth and shiny integument of S. llama suggests that it nests in a relatively wet microhabitat.

Identification
Branstetter (2013) - Integument black to brown-black; medium-sized species (see HL, ML, PrW below); anterior margin of clypeus with shallow median emargination; basal margin of mandible straight, without notch or substantial depression; head and mesosoma mostly smooth and shining; mesosoma compact, with promesonotum distinctly bulging; petiolar node robust, tall, and distinctly angled posteriad; propodeal spines forming short broad triangles (PSL 0.09–0.14, PSI 1.7-2.5); setae on gastral tergites sparse, long, and suberect; eye of moderate size (EL 0.11–0.15, REL 19-23), ovalshaped, with 6–8 ommatidia at greatest diameter; frontal lobes narrow, not obscuring torular lobe in full-face view (FLD 0.14-0.18, FLI 25-28). Similar species: Stenamma lobinodus, Stenamma tiburon.

With its mostly smooth sculpture and bulging promesonotum, S. llama is a very recognizable species. These characters, along with those given above, should make it easy to separate from all other Stenamma species.

Distribution
Southern Mexico to Guatemala. No records from Belize.

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

Castes
Known only from the worker caste.

Nomenclature

 *  llama. Stenamma llama Branstetter, 2013: 147, figs. 104, 105 (w.) GUATEMALA.

Worker
(8 measured) HL 0.59–0.72 (0.70), HW 0.56–0.69 (0.64), FLD 0.14–0.18 (0.17), PCW 0.05–0.07 (0.06), SL 0.46–0.56 (0.55), EL 0.11–0.15 (0.14), ACL 0.45–0.53 (0.52), ML 0.76–0.99 (0.90), PrW 0.41–0.55 (0.50), PSL 0.09–0.14 (0.12), SDL 0.05–0.08 (0.07), PL 0.31–0.41 (0.38), PH 0.23–0.31 (0.31), PW 0.14–0.20 (0.19), PPL 0.17–0.21 (0.21), PPW 0.18–0.26 (0.23), MFL 0.52– 0.65 (0.63), MTL 0.39–0.50 (0.48), CI 92–96 (92), SI 80–85 (85), REL 19–23 (21), FLI 25–28 (27), PSI 1.7–2.5 (1.8), MFI 101–113 (101), ACI1 65–70 (68), ACI2 91–98 (95).

Medium-sized species; general body color black to red- or brown-black, with mandibles and appendages lighter, usually dark brown to yellow-brown; setae light brown; mandible with 6 teeth, consisting of 3 distinct apical teeth, a basal tooth, and 2 inner teeth, which are often worn and indistinct; basal margin of mandible relatively straight, without any notch or significant depression; dorsal surface of mandible mostly smooth and shining, with scattered piligerous punctae and a few short basal striae; median lobe of clypeus with pair of very faint vestigial carinulae that diverge toward anterior margin, apex with a short transverse carinula, remainder of clypeus mostly smooth and shiny; posterior extension of clypeus between frontal lobes moderately broad (PCW 0.05-0.07), with subparallel to slightly diverging sides; frontal lobes narrow, not obscuring torular lobes in full-face view; head roughly oval-shaped (CI 92-96), but appearing somewhat tear drop-shaped because of the angled anterior margin of the clypeus and position of eyes; posterior margin of the head flat, never distinctly depressed medially; eye of moderate size (EL 0.11–0.15, REL 19-23), oval-shaped, with 6–8 ommatidia at greatest diameter; face almost completely smooth and shining, with scattered piligerous punctae and a few longitudinal carinulae on gena; scape short (SI 80-85), not reaching posterior margin of head when laid back; scape mostly smooth and shining, with scattered piligerous punctae, and sometimes a few fine striae; flagellum with a distinct 4-segmented antennal club; mesosoma usually mostly smooth and shiny, with some longitudinal carinae in metanotal groove, and a few scattered rugulae on propodeum, but some specimens with more developed sculpture on mesonotum, mesopleuron, and propodeum, consisting of faint carinulae and punctae; promesonotum domed and distinctly bulging upwards above head and propodeum; promesonotal suture usually completely effaced dorsally, but in a few specimens pronotum appears separated from mesonotum; metanotal groove distinct and of moderate depth; propodeal spines short, forming broad triangles (PSL 0.09–0.14, PSI 1.7-2.5); petiole of moderate length (PL/HW 0.52–0.62), node in profile robust and very tall (PH/PL 0.66–0.80), with anterior face longer and more sloping than posterior face, dorsum of node distinctly angled posteriad, and almost reaching a sharp apex; postpetiole in profile subcircular to oval-shaped, somewhat globular, always smaller than petiolar node (PPH/PH 0.70–0.84), dorsum usually with a somewhat distinct longitudinal median lobe; petiole and postpetiole mostly punctate, sometimes with faint rugulae, anterior faces of nodes smooth and shiny; gaster smooth and shiny except scattered piligerous punctae; most of body with moderately long, erect to subdecumbent setae; scapes with subdecumbent to decumbent setae; setae on legs mostly decumbent to appressed, with some suberect setae on femoral venters and coxae.

Type Material
Holotype worker. GUATEMALA: Zacapa, 2km SE La Unión, 14.95284N 89.27655W ±60m, 1450m, 14 May 2009 (LLAMA, collection Ba-B- 03-4-04-13) USNM, specimen CASENT0605236. Paratypes: same data as holotype but 14.94654°N, 89.27600°W ±6m, 1550m, 12 May 2009 (LLAMA, Wa-B- 03-1-01) 1w, CASC, CASENT0604931; 14.94711°N, 89.27677°W ±50m, 1550m, 12 May 2009 (LLAMA, Wa-B-03-1-36) 1w, MGBPC, CASENT0604952; 14.95436°N, 89.27690°W ±50m, 1430m, 12 May 2009 (LLAMA, Wa-B-03-2-10) 1w, MCZ, CASENT0604975, 1w, UCDC, CASENT0606186, 1w, UNAM, CASENT0604974; 14.95369°N, 89.27614°W ±50m, 1430m, 12 May 2009 (LLA- MA, Wa-B-03-2-32) 1w, UVGC, CASENT0604982.

Etymology
The specific epithet llama is used to honor the Leaf Litter Arthropods of MesoAmerica (LLAMA) project, which is responsible for collecting this species.

References based on Global Ant Biodiversity Informatics

 * Branstetter M.G. 2013. Revision of the Middle American clade of the ant genus Stenamma Westwood (Hymenoptera, Formicidae, Myrmicinae). ZooKeys 295: 1277
 * 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. L., and M. G. Branstetter. 2018. The truncated bell: an enigmatic but pervasive elevational diversity pattern in Middle American ants. Ecography 41: 1-12.