Stenamma nanozoi, Branstetter, Michael G., 2013

Branstetter, Michael G., 2013, Revision of the Middle American clade of the ant genus Stenamma Westwood (Hymenoptera, Formicidae, Myrmicinae), ZooKeys 295, pp. 1-277 : 160-164

Stenamma nanozoi sp. n. Worker: Figure 128; Queen: Figure 129 A–D; Male: Figure 129 E–G: Map: Figure 130

Type material.

Holotype worker. HONDURAS, 12km SW La Ceiba La Ceiba, 15.69175°N, 86.86977°W ± 20m, 200m, 19 Jun 2010, tropical rainforest, ex sifted leaf litter (LLAMA, collection Wa-C-09-2-07) [USNM, specimen CASENT0621828]. Paratypes: same data as holotype [1dq, 1w, USNM, CASENT0621826, CASENT0621827]; same data but 15.69449°N, 86.86339°W ± 20m, 200m, 19 Jun 2010 (LLAMA, Wa-C-09-2-25) [1dq, 1w, CAS, CASENT0623384, CASENT0623388], [1dq, 1w, EAPZ, CASENT0623385, CASENT0623389], [1w, ECOSCE, CASENT0623390], [1w, FMNH, CASENT0623391], [1w, ICN, CASENT0623392], [1dq, 1w INBio, CASENT0623386, CASENT0623393], [1w, JTLC, CASENT0623394], [1w, LACM, CASENT0623395], [1dq, 2w, MGBPC, CASENT0623387, CASENT0623396, CASENT0623397]; 15.69449°N, 86.86311°W ± 20m, 200M, 19 Jun 2010 (LLAMA, Wa-C-09-1-31) [1dq, 1w, MCZ, CASENT0623400, CASENT0623402], [1w, MZSP, CASENT0623403], [1dq, 1w, UCD, CASENT0623401, CASENT0623404], [1w, UNAM, CASENT0623405], [1w, UVGC, CASENT0623406].

Worker diagnosis.

Integument mostly dark red-brown to brown; small-sized species (see HL, ML, PrW below); basal margin of mandible sinuous, with a small basal notch and accompanying tooth; anterior clypeal margin viewed at anterodorsal angle forming 4 blunt teeth (only outer teeth visible in full-face view); pilosity on gastral tergites mostly forming a moderately sparse layer of thickened suberect setae, with only a few thin decumbent setae present; face mostly rugoreticulate; mesosoma mostly rugulose and punctate, without large areas of smooth cuticle; eye of small to moderate size (EL 0.08-0.10, REL 15-18), oval-shaped, with 4-5 ommatidia at greatest diameter; propodeal spines tuberculate (PSL 0.07-0.09, PSI 1.2-1.4); frontal lobes somewhat expanded (FLD 0.14-0.16, FLI 28-31), but not completely obscuring torular lobes in full-face view. Similar species: Stenamma nonotch , Stenamma saenzae , Stenamma sandinista , Stenamma schmidti .

Geographic range.

Honduras.

Worker description.

(10 measured) HL 0.56-0.63 (0.61), HW 0.49-0.56 (0.54), FLD 0.14-0.16 (0.16), PCW 0.03 (0.03), SL 0.48-0.53 (0.51), EL 0.08-0.10 (0.10), ACL 0.48-0.53 (0.53), ML 0.68-0.76 (0.74), PrW 0.35-0.40 (0.38), PSL 0.07-0.09 (0.09), SDL 0.05-0.07 (0.07), PL 0.25-0.28 (0.27), PH 0.14-0.17 (0.15), PW 0.11-0.14 (0.13), PPL 0.13-0.16 (0.15), PPH 0.12-0.15 (0.14), PPW 0.14-0.16 (0.15), MFL 0.48-0.55 (0.55), MTL 0.39-0.44 (0.43), CI 87-92 (89), SI 90-99 (95), REL 15-18 (18), FLI 28-31 (30), PSI 1.2-1.4 (1.3), MFI 97-104 (98), ACI1 65-69 (66), ACI2 96-103 (103).

Small-sized species; general body color dark red-brown to brown, with appendages lighter, brown to yellow-brown toward extremities; setae golden brown; mandible with 6 teeth, basal tooth often well-defined, projecting; basal margin of mandible sinuous, with a distinct basal notch and accompanying small tooth; mandible mostly smooth, except for scattered piligerous punctae, and some striae around the basal and along lateral surface; anterior clypeal margin in anterodorsal view undulating, forming 4 blunt teeth (only outer teeth visible in full-face view); median lobe of clypeus with a pair of somewhat distinct longitudinal carinulae, that diverge toward anterior margin, apex of lobe with a short transverse carinula, remainder of clypeus mostly smooth; posterior extension of clypeus between antennal insertions somewhat narrow (FLD 0.14-0.16, FLI 28-31), with sides diverging slightly posteriad; frontal lobes somewhat expanded (FLD 0.14-0.16, FLI 28-31), but not completely obscuring torular lobes in full-face view; head roughly oval-shaped (CI 87-92), with posterior margin distinctly depressed medially; eye of small to moderate size (EL 0.08-0.10, REL 15-18), oval-shaped, with 4-5 ommatidia at greatest diameter; face mostly strongly rugoreticulate, with a few longitudinal carinulae along midline near frontal lobes; scape of moderate length (SI 90-99), not quite reaching posterior margin when laid back; scape surface mostly smooth, with faint striations and piligerous punctae; flagellum with a distinct 4-segmented antennal club; dorsum of pronotum with irregular longitudinal rugulae that sometimes merge, dorsum of metanotum more rugoreticulate-punctate, side of pronotum mostly carinulate, with a small patch of smooth cuticle near ventral margin, mesopleuron and side of propodeum rugulose-punctate, propodeal dorsum and upper half of declivity with transverse carinulae; promesonotum in profile low-domed, roughly symmetrical, but anterior face distinctly longer than posterior face; metanotal groove of moderate depth and width, sometimes with a small central welt (metanotum); propodeal spines tuberculate (PSL 0.07-0.09, PSI 1.2-1.4); petiole in profile of moderate length (PL/HW 0.48-0.54), peduncle somewhat slender, narrowing toward body; petiolar node of moderate height (PH/PL 0.52-0.61), asymmetrical, with anterior face slightly longer and more sloping than posterior face, dorsum of node narrowly rounded, almost becoming a well-defined apex, node always pointing distinctly posteriad; postpetiole in profile subspherical to oblong, appearing somewhat compressed anteroposteriorly, roughly symmetrical, and similar in size to slightly smaller than petiolar node (PPH/PH 0.83-0.99); anterior faces of petiolar and postpetiolar nodes mostly smooth, remaining surfaces mostly punctate, with some rugulae on posterior half of postpetiole; gaster mostly smooth and shiny, with scattered piligerous punctae; face pilosity short, bilayered; dorsum of mesosoma and gaster mostly with a sparse layer of thickened, suberect setae, gaster with a few thin decumbent setae; setae on scapes and legs mostly appressed, with some suberect setae on femoral venters and coxae.

Queen description.

(5 measured) HL 0.57-0.63 (0.62), HW 0.51-0.58 (0.57), FLD 0.16-0.18 (0.17), PCW 0.03-0.04 (0.04), SL 0.48-0.52 (0.52), EL 0.14-0.16 (0.16), ACL 0.48-0.52 (0.51), ML 0.75-0.85 (0.85), PrW 0.43-0.49 (0.49), PSL 0.09-0.11 (0.11), SDL 0.07-0.09 (0.08), PL 0.27-0.32 (0.31), PH 0.16-0.17 (0.17), PW 0.12-0.15 (0.15), PPL 0.14-0.15 (0.15), PPH 0.14-0.17 (0.17), PPW 0.15-0.18 (0.18), MFL 0.50-0.56 (0.56), MTL 0.40-0.45 (0.45), CI 90-92 (92), SI 90-97 (91), REL 26-28 (28), FLI 31-32 (31), PSI 1.2-1.4 (1.4), MFI 99-104 (102), ACI1 65, ACI2 99-101 (100).

Same as worker except for standard queen modifications and as follows: pronotum transversely carinulate, with dorsum of cervical shield punctate; mesoscutum longitudinally rugulose, with some irregular reticulations; scutellum longitudinally rugulose to rugoreticulate, usually with a small patch of smooth cuticle mesad; propodeum with transverse carinulae that wrap around surface; mesopleuron mostly smooth; pilosity on gaster distinctly bilayered, with a stout layer of long suberect to subdecumbent setae, and a very dense layer of decumbent to appressed pubescence; wing venation as in Figure 129D.

Male.

See Figure 129 E–G.

Biology.

Stenamma nanozoi is mainly an inhabitant of lowland wet forest, with most specimens collected between 0-600 m elevation. However, a few specimens have been collected from montane Liquidambar forest at Celaque in Honduras between 1500-1600 m. All collections, except for one cookie bait sample, were made from sifted leaf litter taken from the forest floor.

Comments.

This species can be separated from similar forms by its mandible structure, eye size, gastral pilosity, facial sculpture, and overall size. Geography is also useful, as Stenamma nanozoi is known from only a few sites in Honduras, mostly at low elevation.

Given the complexity of the Stenamma schmidti complex (see below), it could be that Stenamma nanozoi represents an allopatric variant of Stenamma schmidti . I have decided to separate it out as a distinct species because it occurs at several sites in Honduras and maintains its distinctive features, and molecular data show it to be sister to Stenamma sandinista and outside of the clade that includes most Stenamma schmidti -complex forms. However, within the Stenamma schmidti complex there are several low-elevation variants that have some of the same characteristics as Stenamma nanozoi , mainly small size and thickened gastral setae. Thus, I view the species status of Stenamma nanozoi as somewhat tentative.

Material examined.

HONDURAS: Atlántida: 12km SW La Ceiba, 15.69161°N, 86.86677°W, 280m, 19 Jun 2010 (LLAMA); PN Pico Bonito, 7.8km SSW La Ceiba, 15.69040°N, 86.90272°W, 150m, 2 Oct 2008 (M. G. Branstetter); 7km SW Tela, 15.72346°N, 87.45178°W, 190m, 15 Jun 2010; Comayagua: PN Cerro Azul Meambar, 14.87038°N, 87.89896°W, 1120m, 20 May 2010; Gracias a Dios: Las Marias, 15.66352°N, 84.85799°W, 60m, 8 Jun 2010 (LLAMA); Las Marias, 15.72200°N, 84.88325°W, 380m, 10 Jun 2010 (LLAMA); Las Marias, 15.72153°N, 84.88123°W, 560m, 10 Jun 2010 (LLAMA); Las Marias, 15.72235°N, 84.88480°W, 620m, 10 Jun 2010 (LLAMA);Lempira: PN Celaque, 7.3km SW Graçias, 14.56370°N, 88.64923°W, 1530m, 30 Sep 2008 (M. G. Branstetter).