Stenamma brujita

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Stenamma brujita
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Stenammini
Genus: Stenamma
Species: S. brujita
Binomial name
Stenamma brujita
Branstetter, 2013

Stenamma brujita casent0126254 p 1 high.jpg

Stenamma brujita casent0126254 d 1 high.jpg

Specimen Labels

Stenamma brujita is known only from Winkler and Berlese samples of leaf litter collected from the floor of wet forest habitats (e.g. lowland rainforest, montane wet forest, cloud forest, pine cloud forest, oak-pine forest). The species has a broad elevational range, occurring from 200–1800 m, but it is most common at midelevations (1000–1500 m).

Identification

Branstetter (2013) - Integument mostly black, red-black, or brown; medium to large-sized species (see HL, ML, PrW below); head and mesosoma foveate to coarse rugoreticulate; eye relatively small (EL 0.09–0.13, REL 10–14), circular, and slightly bulging, with 5–7 ommatidia at greatest diameter; pilosity on gastral dorsum long, dense and mostly suberect; propodeal spines tuberculate to long and robust, usually of moderate length (PSL 0.15–0.37, PSI 1.3–2.9); anterior clypeal margin forming a single shallow to deep median emargination, or rarely, 4 blunt teeth; basal margin of mandible straight to sinuous, sometimes with a broad basal depression, but without a distinct notch or tooth; 4-segmented antennal club indistinct.

The combination of large size, small eyes, and foveate sculpture make Stenamma brujita a very distinctive species, unlikely to be confused with any other Middle American clade Stenamma. However, Stenamma zelum, which is not closely related to S. brujita (Branstetter 2012), has converged on a similar phenotype and may cause problems with identification. Fortunately, these two species are geographically isolated from one another, with S. brujita reaching only as far south as northwestern Honduras, and S. zelum extending only as far north as northeastern Honduras. Using morphology, Stenamma brujita can be distinguished from S. zelum by its more rounded head (rectangular in Stenamma zelum), longer propodeal spines (PSI 1.3–2.9 vs. 1.0–1.3), and lower FLI (27–31 vs. 31–34). In addition, the anterior clypeal margin forms four sharp teeth in S. zelum, with the outer teeth usually strongly projecting. In contrast, most populations of S. brujita have the anterior clypeal margin forming a single median emargination (all Honduras populations like this), and in those specimens that do have clypeal teeth, the teeth are all blunt.

Stenamma brujita is quite variable throughout its range and may comprise a complex of several species.

Keys including this Species

Distribution

Atlantic Slope of Mexico to Honduras.

Distribution based on Regional Taxon Lists

Neotropical Region: Guatemala (type locality), Honduras, Mexico.


Distribution based on AntMaps

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Distribution based on AntWeb specimens

Check data from AntWeb

Biology

Castes

Males have yet to be collected.

Worker

Queen

Nomenclature

The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • brujita. Stenamma brujita Branstetter, 2013: 56, figs. 54-57 (w.q.) GUATEMALA.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Worker

(21 measured) HL 0.90–1.20 (1.05), HW 0.77–1.15 (1.00), FLD 0.21–0.32 (0.29), PCW 0.04–0.07 (0.06), SL 0.75–1.01 (0.93), EL 0.09–0.13 (0.12), ACL 0.63–0.78 (0.72), ML 1.15–1.62 (1.45), PrW 0.52–0.78 (0.70), PSL 0.15–0.37, SDL 0.08–0.16, PL 0.45–0.64 (0.56), PH 0.21–0.35 (0.27), PW 0.15– 0.24 (0.21), PPL 0.21–0.31 (0.26), PPH 0.18–0.28 (0.24), PPW 0.20–0.30 (0.27), MFL 0.81–1.25 (1.10), MTL 0.66–0.95 (0.88), CI 85–96 (96), SI 85–99 (88), REL 10–14 (12), FLI 25–31 (29), PSI 1.3–2.9 (2.3), MFI 86–105 (91), ACI1 62–65 (64), ACI2 78–89 (82).

Medium to large-sized species; general body color usually red-black (type population) to black, with patches of brown, but some populations more uniformly brown; mandibles and appendages always lighter than body, brown to orange-brown; setae golden brown; mandible with 4–8 teeth (usually 7), consisting of 3–4 distinct apical teeth, a basal tooth, and a variable number of inner teeth, which are often worn and indistinct; basal tooth usually of moderate size (type population), but sometimes more robust and projecting; basal margin of mandible straight to slightly sinuous, sometimes with a shallow, broad basal depression, but without a distinct notch or tooth; mandible mostly smooth and shining, with scattered piligerous punctae and a few lateral striae; median lobe of clypeus usually slightly produced and clearly visible in full-face view (type population), but sometimes becoming obliquely flattened and angled more dorsoventrally, making it less visible; anterior clypeal margin varying from having a shallow to deep median emargination (type population), to forming 4 distinct blunt teeth; median lobe usually with a pair of faint longitudinal carinulae that diverge toward anterior margin, apex of lobe with a faint to strong transverse carinula; posterior extension of clypeus between frontal lobes of relatively moderate width (PCW 0.04–0.07), with sides subparallel to hour-glass-shaped; frontal lobes average to slightly expanded outward (FLD 0.21–0.32, FLI 25–31), with underlying torular lobes always visible in full-face view; head in full-face view roughly oval shaped to subcircular (CI 85–97), with posterior margin slightly to distinctly depressed medi- ally; eyes relatively small (EL 0.09–0.13, REL 10–14), circular, and somewhat bulging, with 5–7 ommatidia at greatest diameter; head foveate to coarsely rugoreticulate, shiny, often with a few short costae extending back from frontal lobes, interstices with piligerous punctae; scape relatively short, not reaching posterior margin of head when laid back (SI 85–99); scape shiny, usually with only scattered piligerous punctae (type population), but sometimes more robust, with punctae deeper and broader, becoming foveolae; flagellum with indistinct 4-segmented antennal club; mesosoma robust, foveate to coarsely rugoreticulate, with foveae most prominent on promesonotal dorsum; propodeal spines varying from short tubercles to long robust spines (PSL 0.15–0.37, PSI 1.3–2.9), which are usually spiniform and project dorsoposteriorly (type population), but sometimes form robust vertical pointing triangles; promesonotum in profile varying from being domed and nearly symmetrical (type population), to domed and asymmetrical, with apex occurring anterior of midpoint, to high-domed and asymmetrical; humeral angles rounded and indistinct, to becoming produced and angulate (type population), the latter occurring when the promesonotal side is scalloped slightly inward; metanotal grove present, but variable in depth and degree of distinctness; anterodorsal margin of propodeum in profile flat to distinctly raised into a welt (type population); propodeal declivity with a variable number of transverse carinae, often mostly smooth and shiny; petiole shape in profile usually appearing relatively long and somewhat gracile (PL/HW 0.53–0.63), with a small distinct node (PH/PL 0.45–0.55) (type population), but sometimes petiole is more robust and strongly wedge-shaped, without a clear distinction between the node and peduncle; postpetiole in profile usually low-domed, nearly symmetrical, and appearing as high or slightly smaller than petiolar node (type population), but sometimes postpetiole distinctly larger than petiolar node; postpetiole in dorsal view elongate, and reaching its widest point near posterior margin; waist sculpture variable, nodes usually mostly smooth and shiny, but sometimes more punctate and/or with longitudinal costae or rugulae, ventral surface punctate, dorsal surface of peduncle punctate and with a variable number of rugulae; gaster mostly smooth and shiny, with scattered piligerous punctae, and short furrows on anterior constriction where gaster inserts into postpetiole; most of body with rela- tively long standing pilosity; scape either with a single layer of mostly decumbent setae, or bilayered with a sparse layer of longer suberect setae over a denser decumbent layer (type population); gastral pilosity relatively long and somewhat dense, with most setae suberect to subdecumbent; setae on legs suberect to decumbent, with some popula- tions having predominately suberect setae (type population) and others mainly decum- bent setae, longer suberect setae always present on femoral venters and coxae.

Queen

Stenamma brujita casent0621749 p 2 high.jpg

(5 measured) HL 0.96–1.03 (1.03), HW 0.91–0.99 (0.99), FLD 0.26–0.29 (0.29), PCW 0.05–0.07 (0.06), SL 0.84–0.89 (0.89), EL 0.17–0.19 (0.17) ACL 0.68–0.72 (0.71), ML 1.47–1.57 (1.57), PrW 0.76–0.82 (0.82), PSL 0.18–0.28 (0.28), SDL 0.13–0.16 (0.13), PL 0.59–0.61 (0.60), PH 0.28–0.32 (0.31), PW 0.22–0.25 (0.24), PPL 0.27–0.33 (0.32), PPH 0.23–0.28 (0.28), PPW 0.25– 0.31 (0.29), MFL 1.01–1.06 (1.06), MTL 0.79–0.85 (0.85), CI 93–97 (97), SI 86–94 (90), REL 17–20 (17), FLI 28–31 (29), PSI 1.1–2.1 (2.1), MFI 87–95 (93), ACI1 63–64 (63), ACI2 80–85 (80).

Same as worker except for standard queen modifications and the following: Propodeal spines less variable (PSL 0.18–0.28, PSI 1.1–2.1), usually present, of moderate length, and thick at base (only Nahá population with spines tuberculate); setae on scape less variable, usually with a sparse layer of longer suberect setae and a layer of denser decumbent setae (only Nahá population with setae uniformly subdecumbent); wing venation as shown in photo.

Type Material

Holotype Specimen Labels

Holotype worker. GUATEMALA, Zacapa: 2km SE La Unión, 14.94706°N, 89.27660°W ±50m, 1550m, 12 May 2009, cloud forest, ex sifted leaf litter (LLAMA, collection Wa-B-03-1-32) USNM, specimen CASENT0604945. Paratypes: same data as holotype but 14.94460°N, 89.27726°W ±57m, 1550m, 12 May 2009 (LLA¬MA, Wm-B-03-1-04), 1w, CASC, CASENT0623248, 1w, EAPZ, CASENT0623249, 1w, ECOSCE, CASENT0623250, 1w, FMNH, CASENT0623251, 1w, ICN, CASENT0623252, 1w, INBC, CASENT0623253, 1w, JTLC, CASENT0623527, 1w, LACM, CASENT0623254, 2w, MGBPC, CASENT0623528, CASENT0623529, 1w, MCZ, CASENT0623255, 1w, MZSP, CASENT0623256, 1w, UCDC, CASENT0623257, 1w, UNAM, CASENT0623258, 1dq, 1w, USNM, CASENT0606239, CASENT0606656, 1w, UVGC, CASENT0623259.

Etymology

The specific epithet brujita is the spanish word meaning little witch. The name is used to reference the fact that ants are small, most are female, and that S. brujita has rough sculpturing, much like the skin on a stereotypical witch.

References

  • Branstetter, M. G. 2012. Origin and diversification of the cryptic ant genus Stenamma Westwood (Hymenoptera: Formicidae), inferred from multilocus molecular data, biogeography and natural history. Systematic Entomology 37:478-496. doi:10.1111/j.1365-3113.2012.00624.x.
  • Branstetter, M.G. 2013. Revision of the Middle American clade of the ant genus Stenamma Westwood (Hymenoptera, Formicidae, Myrmicinae). ZooKeys 295, 1–277. doi:10.3897/zookeys.295.4905

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.
  • Longino J. et al. ADMAC project. Accessed on March 24th 2017 at https://sites.google.com/site/admacsite/