Stenamma felixi Mann

Branstetter, Michael G., 2013, Revision of the Middle American clade of the ant genus Stenamma Westwood (Hymenoptera, Formicidae, Myrmicinae), ZooKeys 295, pp. 1-277 : 89-94

Stenamma felixi Mann Worker: Figures 86, 87; Queen: Figure 88 A–D; Male: Figure 88 E–G; Map: Figure 89

Stenamma felixi Mann, 1922: 21, fig. 10. Lectotype worker (here designated): HONDURAS, [ Atlántida]: San Juan Pueblo, [ca. 15.583°N, 87.233°W], Feb–Mar 1920 (W. M. Mann) (USNM, Cotype. No. 24448, pin CASENT0126355, bottom specimen) (USNM) [examined]. Smith, 1962: 34, worker description. Branstetter, 2009: phylogeny. Branstetter, 2012: phylogeny.

Worker diagnosis.

Integument mostly black to dark brown; medium- to large-sized species (see HL, ML, PrW below); anterior clypeal margin with a median emargination; basal margin of mandible straight to slightly sinuous, without a basal notch or depression; head and mesosoma usually densely sculptured, with sharp carinae, rugae, or rugoreticulae; eye relatively large (EL 0.16-0.20, REL 18-22), oval-shaped, with 8-11 ommatidia at greatest diameter; propodeal spines absent, propodeum forming shallow, blunt angles where propodeal dorsum and declivity converge (PSL 0.07-0.11, PSI 0.8-1.1); setae on gastral tergites mostly sparse, long, and suberect, only sometimes with a few short decumbent setae; frontal lobes of moderate width (FLD 0.22-0.26, FLI 25-29), not completely obscuring torular lobes in full face view; metafemur relatively long (MFI 75-88). Similar species: Stenamma manni , Stenamma schmidti .

Geographic range.

Mexico (Atlantic slope) to Ecuador.

Worker description.

(10 measured) HL 0.90-1.19 (1.00), HW 0.81-1.04 (0.87), FLD 0.22-0.26 (0.22), PCW 0.04-0.09 (0.05), SL 0.69-0.95 (0.81), EL 0.16-0.20 (0.17), ACL 0.70-0.92 (0.79), ML 1.25-1.62 (1.37), PrW 0.58-0.74 (0.62), PSL 0.07-0.11 (0.09), SDL 0.07-0.13 (0.08), PL 0.41-0.52 (0.45), PH 0.25-0.32 (0.29), PW 0.16-0.23 (0.23), PPL 0.24-0.33 (0.28), PPH 0.21-0.27 (0.23), PPW 0.18-0.27 (0.18), MFL 0.93-1.28 (1.08), MTL 0.71-0.98 (0.81), CI 83-90 (87), SI 84-101 (93), REL 18-22 (20), FLI 25-29 (26), PSI 0.8-1.1 (1.1), MFI 75-88 (81), ACI1 57-62 (59), ACI2 93-102 (97).

Medium- to large-sized species; general body color mostly black to dark brown, with appendages lighter, brown to orange-brown toward extremities; setae dark gold-brown; mandible with 5-6 teeth, consisting of 4 distinct apical teeth, a basal tooth, and 1 tooth in between, which is smaller and often effaced; basal margin of mandible straight to slightly sinuous, without a basal notch or depression; mandible mostly smooth, except for scattered piligerous punctae, and some lateral striations; anterior clypeal margin with a shallow median emargination; median lobe of clypeus with at least a pair of distinct longitudinal carinulae that diverge toward anterior margin, sometimes with a few additional faint carinulae, apex of lobe smooth, or with some faint transverse carinulae; remainder of clypeus mostly smooth and shiny; posterior extension of clypeus between frontal lobes of moderate width (PCW 0.04-0.09), sides subparallel to slightly hour-glass-shaped; frontal lobes of moderate width (FLD 0.22-0.26, FLI 25-29), not greatly obscuring torular lobes in full face view; head usually roughly oval-shaped, but some populations with posterior margin distinctly broader than anterior margin, making head appear more triangular (CI 83-90), posterior margin always depressed medially; eye relatively large (EL 0.16-0.20, REL 18-22), oval-shaped, with 8-11 ommatidia at greatest diameter; face densely sculptured, but sculpture type variable, most often with some longitudinal rugae/carinae along midline, transitioning to rugoreticulae toward lateral margins, but sometimes face almost completely rugoreticulate, or completely carinate, depth and sharpness of sculpture variable; scape of moderate length (SI 84-101), just reaching posterior margin of head when laid back; scape surface mostly smooth, but with distinct carinulae, and scattered piligerous punctures; scape sometimes appearing thickened and more robust; flagellum with distinct 4-segmented antennal club; mesosoma mostly densely sculptured, but sculpture type variable; dorsum of pronotum usually rugose (longitudinal orientation) to rugoreticulate, but sometimes carinate, anterior declivity of pronotum with transverse carinulae; dorsum of mesonotum rugoreticulate to transversely carinate, sometimes intermediate; side of pronotum rugulose to carinate; katepisternum mostly smooth, with some rugulae on upper half; dorsum and declivity of propodeum transversely carinate/carinulate; side of propodeum rugose; promesonotum in profile domed (higher than average), symmetrical to slightly asymmetrical, with location of apex variable; metanotal groove distinct, but narrow; dorsum of propodeum in profile distinctly longer than declivity; propodeal spines absent, propodeum forming shallow, blunt angles where dorsum and declivity converge (PSL 0.07-0.11, PSI 0.8-1.1); petiole of moderate length (PL/HW 0.48-0.55); petiolar node of moderate height (PH/PL 0.60-0.64), subconical in shape, usually pointing vertically to only slightly posteriad, dorsum narrowly to somewhat broadly rounded, posterior margin of petiole, where postpetiole inserts, distinctly bent downwards; postpetiole in profile nearly symmetrical, with anterior face slightly longer than posterior face, postpetiole similar in size to petiolar node (PPH/PH 0.78-0.85); petiole and postpetiole usually mostly punctate, with only anterior faces of nodes smooth, but sometimes nodes mostly smooth, with punctae faint; gaster smooth, with scattered piligerous punctae; most of body dorsum with standing pilosity; setae on gastral tergites mostly sparse, long, and suberect, only sometimes with a few short decumbent setae; setae on scapes subdecumbent to appressed; setae on legs decumbent to appressed, with a few suberect setae on femoral venters and coxae.

Queen description.

(6 measured) HL 1.00-1.17 (1.07), HW 0.85-0.98 (0.89), FLD 0.25-0.27 (0.25), PCW 0.05-0.08 (0.07), SL 0.76-0.92 (0.84), EL 0.23-0.30 (0.29), ACL 0.69-0.91 (0.83), ML 1.45-1.75 (1.57), PrW 0.79-0.91 (0.83), PSL 0.11-0.15 (0.13), SDL 0.12-0.16 (0.14), PL 0.51-0.59 (0.55), PH 0.31-0.36 (0.33), PW 0.21-0.25 (0.23), PPL 0.30-0.37 (0.35), PPH 0.26-0.31 (0.29), PPW 0.26-0.32 (0.31), MFL 0.96-1.27 (1.11), MTL 0.74-0.95 (0.85), CI 83-88 (83), SI 87-97 (94), REL 27-32 (32), FLI 27-30 (28), PSI 0.9-1.0 (0.9), MFI 76-88 (81), ACI1 58-61 (59), ACI2 90-99 (99).

Same as worker except for standard queen modifications and as follows: pronotum transversely carinulate; mesoscutum longitudinally carinulate, or carinate; scutellum rugoreticulate, or longitudinally carinulate to carinate; propodeum with transverse carinulae/carinae that wrap around surface; mesopleuron usually mostly smooth; pilosity on gastral tergites clearly bilayered, with a sparse layer of long, suberect setae, and a dense layer of appressed pubescence; wing venation in Figure 88D.

Male.

See Figure 88 E–G.

Biology.

Stenamma felixi is one of the most widespread and common species of MAC Stenamma . It occurs from approximately 50-1600 m, but is most common above 500 m, and is always found in wet forest environments, ranging from lowland rainforest to cloud forest. Workers have been collected by sifting leaf litter, beating and sweeping vegetation, baiting, using pitfall and Malaise traps, and by general searching. Nests are generally quite large and have been found in rotting logs on the ground, in tree stumps, under bark of logs, and rarely in mud banks. A few lone foundresses have been found under rotting epiphyte clumps in old treefalls, and some workers have been collected from orchids at quarantine in the U.S. All colonies collected so far have been monogynous. Workers seem to be epigeic, solitary foragers, but nothing is known about dietary preference. A very common experience is to find lone, stray workers running across medium- to large-sized logs in forest.

Comments.

This species is rather distinctive with its large size, lack of propodeal spines, and dense sculpturing. It should not be easily confused with any other MAC species.

Over its range, Stenamma felixi shows considerable variation in the density and orientation of its sculpturing as well as in petiole shape. However, I have only identified one distinct variant (Figure 87) worth describing in more detail. Specimens from Nicaragua and Costa Rica have very deep carinate sculpturing on the face and mesosoma. The facial carinae are usually longitudinal, but occasionally reticulate laterad. The pronotal dorsum has longitudinal carinae, but the side of the pronotum has arcuate carinae that wrap across the dorsum of the metanotum. The head in profile view has a very distinctive shape, in which the posterior margin of the head is very wide compared to the anterior margin, giving the head a somewhat triangular appearance. Lastly, the petiolar and postpetiolar nodes are noticeably smooth. Specimens from Colombia and Ecuador and from north of Nicaragua lose the carinate sculpture. I treat all of the slight sculpture differences among popluations as intraspecific variation as I have found no evidence of sympatry among forms.

Material examined.

BELIZE: Cayo: Chiquibul N.P., Doyle’s Delight, 16.48972°N, 89.04583°W, 950m, 20-27 Aug 2007 (P. W. Kovarik); Chiquibul N.P., Doyle’s Delight, 16.4833°N, 89.0333°W, 1000m, 19-22 Aug 2007 (P. W. Kovarik); Chiquibul N.P., Doyle’s Delight, 16.49305°N, 89.04694°W, 1100m, 19-28 Aug 2007 (P. W. Kovarik); COLOMBIA: Valle del Cauca: Buenaventura, Bajo Calima, [ca. 3.996°N, 76.974°W], 30m, 16-17 Mar 1967 (Root & Brown); Buenaventura, 3.2km above Río Aguaclara on old rd to Cali, [ca. 3.693°N, 76.925°W], 17-19 Jun 1971 (W. L. Brown); Reserva Forestal Escalerete, [ca. 3.886°N, 77.069°W], 80m, 29 May 2007 (Usma-Aldana); COSTA RICA: Cartago: La Carpintera, [ca. 9.884°N, 83.983°W], 1500m, Apr 1924 (W. M. Mann); Navarro Farm, [ca. 9.8167°N, 83.8833°W,], 1100m, Mar 1924 (W. M. Mann); Guanacaste: Est. Mengo, SW side Volcan Cacao, [ca. 10.933°N, 85.450°W], 1100m, Feb 1989 (GNP Biodiversity Survey); Est. Pitilla, 9km S Sta. Cecilia, [ca. 10.983°N, 85. 433°W], 700m, Jan 1991 (Curso Microhymenoptera); Heredia: La Selva Biol. St., [ca 10.430°N, 84.007°W], 100m, 16 Jan 1979 (S. P. Cover); 11km ESE La Virgen, 10.35°N, 84.05°W, 300m, 15 Feb 2004 (ALAS); 10km NE Vara Blanca, 10.2333°N, 84.0833°W, 1500m, 12 Feb 2005 (ALAS); 16km SSE La Virgen, 10.2667°N, 84.0833°W, 1100m, 14-17 Mar 2001 (ALAS); Limón: Colombiana Farm, [ca. 10.167°N, 83.583°W], Apr 1924 (W. M. Mann); Río Toro Amarillo, vic. Guapiles, [ca. 10.205°N, 83.789°W], 300m, 25 Feb– 9 Mar 1966 (W. L. Brown); Puntarenas: Altamira Biological Station, 9.02922°N, 83.00813°W, 1400m, 30 May 2007 (M. G. Branstetter); 2km W Las Alturas, 8.933°N, 82.850°W, 1260m, 23 Mar 1990 (P. S. Ward); Las Cruces Biological Station, 8.78658°N, 82.95987°W, 1150m, 29 May 2007 (M. G. Branstetter); Monteverde, 0.25km E Lecheria, [ca. 10.307°N, 84.810°W], 1300m, 19 May 1988 (Cover et al.); San José: Bajo La Hondura, Braulio Carillo Nat. Park, [ca. 10.067°N, 83.983°W], 20 Jun 1926 (F. Nevermann); 1km N La Ese, 9.450°N, 83.717°W, 1400m, 5 Aug 1985 (P. S. Ward); Pan-Am Hwy, 23 rd km N San Isidro de General, [ca. 9.466°N, 83.703°W], 1600m, 20-23 Jun 1974 (Harding & Donahue); 2km E San Gerardo, 9.467°N, 83.583°W, 1600m, 4 Aug 1985 (P. S. Ward); ECUADOR: Cañar: 2-6km above Cochancay on Guayaquil-Tambo H’way, [ca. 2.468°S, 79.291°W], 600m, 25 Jul 1973 (W. L. Brown); GUATEMALA: Izabal: 5km NW Morales, 15.51351°N, 88.86647°W, 240m, 18 May 2009 (J. Longino); Petén: 13km NW Machaquilá, 16.44202°N, 89.53495°W, 390m, 28 May 2009 (LLAMA);Zacapa: 2km SE La Unión, 14.94701°N, 89.27594°W, 1550m, 12 May 2009 (LLAMA); Suchitepéquez: 5.5km S Vol. Atitlán, 14.52857°N, 91.19569°W, 1070m, 18 Jun 2009 (LLAMA); HONDURAS: Atlántida: San Juan Pueblo, [ca. 15.583°N, 87.233°W], 100m, Feb–Mar 1920 (W. M. Mann); Cortés: PN Cusuco, 15.48940°N, 88.23732°W, 1290m, 30 May 2010 (LLAMA); Olancho: 9km N Catacamas, 14.93646°N, 85.90488°W, 1340m, 10 May 2010 (M. G. Branstetter); 10km N Catacamas, 14.94125°N, 85.90385°W, 1320m, 10 May 2010 (LLAMA); 11km NNE Catacamas, 14.95031°N, 85.86229°W, 1470m, 12 May 2009 (J. Longino); PN La Muralla, 15.09721°N, 86.73840°W, 1480m, 5 May 2010 (LLAMA); MÉXICO: Chiapas: Lago Metzabok, 17.12360°N, 91.63766°W, 575m, 5 Jun 2008 (LLAMA); Nahá, 16.94885°N, 91.59489°W, 930m, 8 Jun 2008 (LLAMA);Hidalgo: 6.4km SW Chapulhuacán, [ca. 21.155°N, 98.931°W], 1070m, 27 Jun– 1 Jul 1973 (A. F. Newton); between Real del Monte and El Chico, [ca. 20.138°N, 98.673°W], Mar–Aug 1913 (W. M. Mann); Oaxaca: Mirador Grande, 17.89844°N, 96.36253°W, 990m, 14 Aug 2009 (M. G. Branstetter);Puebla: 17km NE Teziutlán, [ca. 19.877°N, 97.310°W], 1940m, 7 Jun 1988 (W. P. MacKay); 24km N Xicotepec de Juarez, [ca. 20.282°N, 97.963°W], 1070m, 17 Jun 1983 (R. S. Anderson); Veracruz: Canyon Río Metlac, near Fortín, [ca. 18.90°N, 97.00°W], 975m, 7-28 Aug 1973 (A. F. Newton); 10km S Orizaba, 18.750°N, 97.083°W, 1500m, 19 Mar 1985 (P. S. Ward); 2.7km N Teocelo, [ca. 19.40°N, 96.98°W], 1130m, 22-24 Jul 1973 (A. F. Newton); 11km N San Andrés Tuxtla, 18.55°N, 96.00°W, 1400m, 23 Mary 1985 (P. S. Ward); 10km NNW Sontecomapan, 18.583°N, 95.083°W, 200m, 20 Mar 1985 (P. S. Ward); NICARAGUA: Jinotega: PN Cerro Saslaya, 13.77173°N, 85.01286°W, 1110m, 12 May 2011 (LLAMA); RNDatanlí El Diablo, 13.10410°N, 85.01286°W, 1110m, 12 May 2011 (LLAMA); RNDatanlí El Diablo, 13.08051°N, 85.87462°W, 1170m, 20 May 2011 (LLAMA); PANAMA: Panama: Cerro Campana, [ca. 8.678°N, 79.928°W], 875m, 17 Jan 1960 (Fairchild & Brown).