Basiceros singularis

AntWiki: The Ants --- Online
Basiceros singularis
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Basiceros
Species: B. singularis
Binomial name
Basiceros singularis
(Smith, F., 1858)

Basiceros singularis casent0900940 p 1 high.jpg

Basiceros singularis casent0900940 d 1 high.jpg

Specimen Labels

Moffet (see the biology section below), conveying some of what he learned about these ants... "One species of ant that will never win a prize for cleanliness is Basiceros singularis of Ecuador. Once thought to be rare, they are in fact fairly common ants that are uncommonly dirty, camouflaging themselves with mud held in place on their bodies by feathery hairs. Workers move at a snail’s pace—not a problem if your favorite prey is, in fact, snail. "

Identification

Probst & Brandão (2022) - Very similar to Basiceros manni. Comparatively large; coloration light brown to brown. Double layer of specialized pilosity distributed as a basal layer of subdecumbent plumose hairs and a layer of fine erect and clavate hairs. In general, specimens densely covered with soil and/or litter particles. Clypeomandibular space ample; anterodorsal region of mandibles and clypeus dorsum usually with squamiform pilosity. Petiole claviform, elongate and with a depressed node. Anterior margin of first gastral sternite medially elevated, with a longitudinal projection in the form of a carina or prominence.

Keys including this Species

Distribution

Brazil: Amazonas, Mato Grosso, Pará, and Rondônia; Colombia; Ecuador; Guyana; French Guiana, Peru; Trinidad and Tobago; and Venezuela.

Latitudinal Distribution Pattern

Latitudinal Range: 10.73333333° to -20.833333°.

 
North
Temperate 		North
Subtropical 		Tropical South
Subtropical 		South
Temperate

Distribution based on Regional Taxon Lists

Neotropical Region: Brazil (type locality), French Guiana, Guyana, Suriname, Trinidad and Tobago.

Distribution based on AntMaps

AntMapLegend.png

Distribution based on AntWeb specimens

Check data from AntWeb

Countries Occupied

Number of countries occupied by this species based on AntWiki Regional Taxon Lists. In general, fewer countries occupied indicates a narrower range, while more countries indicates a more widespread species.
pChart

Estimated Abundance

Relative abundance based on number of AntMaps records per species (this species within the purple bar). Fewer records (to the left) indicates a less abundant/encountered species while more records (to the right) indicates more abundant/encountered species.
pChart

Biology

Probst & Brandão (2022) - Weber (1950) mentions that he found a worker in Trinidad foraging during the day (at 1pm). Brown (1974) collected a colony in the north of the state of Mato Grosso in July 1973, at Fazenda Junqueira Vilela; the colony was nesting on rotting trunks in the shade, and Brown found headless termite bodies with ant workers and reproductives (alate males and gyne) in what looked like grossly-built chambers. Adults presented thanatosis when disturbed and, according to Brown “are exceedingly hard to distinguish by eye”. The author discusses the incrustation presented by this species and conjectures that it could be a product of secretions of nasute termite soldiers (Termitidae: Nasutitermitinae) or even that the ants themselves produced it. Brown ends up commenting that newly hatched adults and alate forms of both sexes did not present particle covering or secretion.

Some specimens from Trinidad & Tobago examined in the present study were covered by oribatid mites. It is not possible to confirm whether such arachnids are phoretic, commensal myrmecophiles, or parasites. Brown (1974) mentions that he dissected workers to determine the number of Malpighian tubules present, recognizing five.

In Dr. Mark Moffett’s photographic exhibition—“Farmers, Warriors, Builders: The Hidden Life of Ants”—organized at the USNM in 2009, one of the photographs depicted a B. singularis worker (identified as B. conjugans) probably preying on a Subulinidae mollusk with a spiral and pointed shell from genus Beckianum or Allopeas, recognized for being litter predators (Dr. Jaime Jardim pers. comm.). This information was already reported for this species—also by Dr. Moffett—in the August 2008 issue of the National Geographic magazine, with a photo recording the moment a B. singularis larva preys on a gastropod with a shell similar to that recorded by Dr. Michael Branstetter inside B. manni nests in Nicaragua. Transcribed below is the report associated with the photograph: “One species of ant that will never win a prize for cleanliness is Basiceros singularis of Ecuador. Once thought to be rare, they are in fact fairly common ants that are uncommonly dirty, camouflaging themselves with mud held in place on their bodies by feathery hairs. Workers move at a snail’s pace—not a problem if your favorite prey is, in fact, snail. The chase ends—finally—with a strike. The ant then drags her booty home to a nest in the rain forest leaf litter composed of only a dozen or so workers and their queen. Stooped over a little colony I’d captured in a petri dish, I photographed a worker feeding a snail to a larva, which gobbled it up from its shell with the enthusiasm of a child lapping ice cream from a cone”.

The fact that B. singularis and B. manni potentially use terrestrial mollusks as prey reinforces the idea of phylogenetic relatedness between these species (see Probst et al. 2019).

Some specimens collected in Peru and Colombia examined for the present study do not have the combination of squamiform hairs on the clypeal dorsum and anterodorsal region of mandibles. However, they also do not have piligerous punctuations in these regions as observed in Basiceros manni specimens, but a combination of irregular and subopaque rugulae. Furthermore, these specimens have the head shape and anteroventral projection of the first gastral sternite exclusive to B. singularis. This peculiarity of Peruvian and Colombian specimens supports the possibility of hybridization between populations of B. manni and B. singularis in these regions. However, more fieldwork is necessary to fill gaps in the distribution of both species to make this assumption more credible. The current distribution of Basiceros singularis in Colombia is many kilometers away from the southernmost distribution of B. manni, which alternatively makes the possibility of hybridization between these species a difficult proposition (Dr. Roberto Guerrero, pers. comm.). Dietz (2004) identified two specimens of B. singularis from Colombia and one from Peru as B. manni, which emphasizes the difficulty of identifying specimens from these locations. In addition, a worker collected in Colombia was considerably smaller than other workers of B. singularis analyzed in the present work (with that size variation reflected in the smallest values obtained for the measurements).

Castes

Probst & Brandão (2022) - As mentioned for Basiceros disciger and Basiceros militaris, B. singularis displays intercastes. The examined morphological mosaic for this species has gynes virtually identical to conspecific workers, differing only by the presence of a median and/or lateral ocelli and a slight scutellar impression, and the most aberrant case of ergatoidism within the genus, in which a gyne presented alar rudiments, even without showing complete development of the mesosomal sclerites associated with flight. Obviously, this brachypterous gyne could not fly. Similar to B. militaris, intercastes and true gynes co-occur in the same colony. Together with a general morphology analogous to conspecific workers, it reinforces a scenario similar to that found by Molet et al. (2009) for Mystrium gynes in Madagascar, with ergatoids having functional ovaries, spermatheca, and alar rudiments, acting as a “multitasking” caste within the colony. Almost all specimens of B. singularis are collected covered by a thick layer of particles that prevents the visualization of morphological changes on the mesosoma and head. The intercaste mosaicism was revealed after the cleaning of several specimens; therefore, the presence of intercastes in this species is probably underestimated.

Worker

Figure 23. Basiceros singularis, worker (CASENT0914890, Ecuador: Napo); A. full-face view, B. lateral view, C. dorsal view. Images by Michele Esposito (CAS).

Intercaste

  • Probst & Brandão 2022. Figure 25. Basiceros singularis intercaste from Trinidad & Tobago: St. Andrew; A–D: MCZ534402/T2-56); A. lateral view of mesosoma, white arrow pointing to wing fossa and wing trace, B. lateral view, C. dorsal view highlighting mesoscutum line (white arrow) and wing trace (black arrow), D. dorsal view; Scale bars: 1 mm.
  • Probst & Brandão 2022. Figure 25. Basiceros singularis intercaste from Trinidad & Tobago: St. Andrew; E–H: (MCZ/T2-56); E. oblique view of mesosoma, white arrow pointing to vestigial hindwing, F. lateral view, G. dorsal view highlighting rudiments of a mesoscutum (left white arrow), mesoscutellum (right white arrow), and forewing trace (black arrow), H. dorsal view. Scale bars: 1 mm.

Queen

Probst & Brandão 2022. Figure 24. Basiceros singularis, gyne (MCZ 534402/T2-56, Trinidad & Tobago: St. Andrew); A. full-face view, B. dorsal view, C. lateral view. Scale bars: A = 0.5 mm, B, C =1 mm.

Male

Probst & Brandão 2022. Figure 24. Basiceros singularis, male (MCZ, Trinidad & Tobago: St. Andrew); D. full-face view, E. dorsal view, F. lateral view. Scale bars: D = 0.5 mm, E, F =1 mm.

Phylogeny

Basiceros

Basiceros sp.n.A

Basiceros convexiceps

Basiceros manni

Basiceros singularis

Basiceros scambognathus

Basiceros conjugans

Basiceros disciger

Basiceros militaris

Based on Probst et al., 2019.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • singularis. Meranoplus singularis Smith, F. 1858b: 195, pl. 13, figs. 6-10 (w.q.) BRAZIL (Amazonas).
    • Type-material: lectotype worker (by designation of Brown & Kempf, 1960: 169 (in text), 175).
    • [Notes (i): the original syntype queen was identified as a species of Trachymyrmex by Weber, 1950c: 5; (ii) this queen was formally excluded from the type-series by Brown & Kempf, 1960: 169, 175.]
    • Type-locality: none given.
    • [Note: in F. Smith’s, 1860c: 78, redescription of the species he gives “Hab. Ega (Brazil)”, accepted as type-locality by Brown & Kempf, 1960: 175: hence type-locality is Brazil: Amazonas, Ega (= Tefé) (H.W. Bates).]
    • Type-depository: BMNH.
    • Wheeler, W.M. 1916c: 9 (q.); Brown, 1974c: 140 (m.); Wheeler, G.C. & Wheeler, J. 1980: 537 (l.); Probst & Brandão, 2022: 59 (intercastes).
    • Combination in Ceratobasis: Smith, F. 1860c: 78;
    • combination in Basiceros: Wheeler, W.M. 1916c: 9.
    • Status as species: Smith, F. 1860c: 78 (redescription); Smith, F. 1862d: 415; Mayr, 1863: 403; Roger, 1863b: 40; Mayr, 1887: 581; Dalla Torre, 1893: 148; Forel, 1895b: 136; Forel, 1911e: 263; Wheeler, W.M. 1916c: 9; Emery, 1924d: 328; Borgmeier, 1927c: 120; Brown, 1949f: 88; Weber, 1950c: 5; Brown & Kempf, 1960: 175 (redescription); Kempf, 1972a: 36; Brown, 1974c: 138; Brandão, 1991: 330; Bolton, 1995b: 80; Feitosa, et al. 2007: 19 (in key); Bezděčková, et al. 2015: 115; Fernández & Serna, 2019: 844; Probst & Brandão, 2022: 56 (redescription).
    • Distribution: Brazil, Colombia, Ecuador, French Guiana, Guyana, Peru, Trinidad, Venezuela.

All of the remainder of the nomenclature section is from Probst & Brandão (2022)

Description

Worker

(n=5). HL 1.29–1.31, HL2 1.43–1.56, HW1 1.09–1.43, MdL 0.90–0.95, SL1 1.18–1.22, SL2 1.19–1.25, PDL 0.12–0.15, A3L 0.03–0.06, AFL 0.47–0.50, FuL 1.19–1.31, EL 0.19–0.25, EW 0.15–0.21, ML 2.05–2.37, MfL 1.72–1.89, MtL 1.37–1.56, PH 0.40, PL 1.06–1.15, PW 0.243–0.47, PPL 0.53–0.64, PPW 0.59–0.67, GL 1.81–1.97, GW 1.25–1.44, TL 7.65–8.40, CI 84–109, CS 1.19–1.37, MCI 69–72, SI 87–108, ESI 15–20, SAI2 253–250, EI1 0.29–0.34, MFI 63–76, PTI 261–282.

Large size compared to other Basiceros. Coloration (when integument is visible, not densely covered with particles) brown to light brown; appendices slightly lighter. Mandibles with same coloration as appendages, slightly reddish-brown; dorsum with tiny piligerous punctuations close to the masticatory margin, remaining surface either covered by coarse piligerous punctuations with squamiform, slightly whitish decumbent or irregularly and superficially rugose; mandibular apex with short yellowish setae; interdental setae present, yellowish and brush-shaped, slightly longer than teeth. Basimandibular seta present, narrow and erect, located at the anteroventral limit of mandibular peduncle. Stipes covered by fine, medium and subdecumbent pilosity; suberect clavate hair on its dorsum close to anterior margin. Labrum densely covered with piligerous punctuations: short, decumbent and squamiform setae. Dorsal surface of clypeus covered by coarse piligerous punctuations, with decumbent, short and squamiform yellowish hairs. Head dorsum predominantly covered by piligerous fovea, pilosity squamiform or with plumose aspect, subdecumbent; long erect to suberect hairs sparse on the anterior portion of head and more abundant near the posterolateral region and vertexal margin. Ventral surface of head covered by piligerous punctuations; hairs long and erect close to head sides and as line on head center, and by squamiform hairs marginating the ventral limit of antennal scrobes. Pilosity on meso- and metasoma as a double layer of specialized hairs. Basal layer composed of yellowish and subdecumbent plumose hairs, more abundantly than on B. manni, as follows: dense, surrounding the anterior margin of pronotum; a little more sparse on pronotum and mesonotum dorsa, on dorsum and lateral of propodeum, on mesopleuron flange near the epicnemial fossa, on the upper portion of mesopleuron, on dorsal surface of petiolar and postpetiolar nodes; petiolar peduncle with plumose hairs on its side; densely covering the postpetiole sternite; gaster pilosity with hairs with plumose aspect and squamiform hairs, relatively sparse; on anterior face and anterolateral portion of procoxae and on the dorsum and anteroventral margin of all coxae. The second layer is composed of erect to suberect hairs, distributed slightly more sparsely than on B. manni, long and slightly apically, present on the meso- and metasoma as follows: dense on the dorsal surface of pronotum, petiolar node, postpetiole and gaster (on the ventral portion, relatively sparse on the anterior region of first segment); one pair present on the metanotal suture; three pairs on the dorsum and sides of propodeum; slightly thinner and sparse on petiolar peduncle; two pairs on each side of the anterior margin of postpetiole sternite; present on the anterior face and anterolateral portion of procoxae; two to three pairs on the dorsum of meso- and metacoxae. Femora and tibiae covered by short subdecumbent hairs, with a flattened aspect on tibiae. Appressed and clavate minute hairs also present on these segments, more easily recognized on the ventral surface of femora, tibiae and basitarsi of all legs. Antennal pilosity unique: subdecumbent squamiform hairs on the basal lobe of scape, dense hairs, erect to suberect on scape dorsum; external margin with long erect hairs and slightly swollen medially, distributed along the crenulation; short and apically curved hairs also following the external margin; ventral face with short, subdecumbent setae; funiculus densely covered with short, decumbent setae.

When it is possible to observe the integument, it is mostly smooth and shiny on glabrous regions. Dorsum of mandibles and clypeus covered by punctuations or rugae. Anteroventral portion of mandibles slightly alveolate. Dorsal surface of labrum finely reticulate. Head irregularly rugose, rugae forming foveae of different sizes; antennal fossa reticulate; antennal scrobe surface punctuate-foveate on its posterior half; ventral face of head granulose-punctuate, punctuations coarse and slightly overlapping. Anterior and lateral margins of pronotum foveate. Mesonotum with lateral costulae, extending to the anterolateral surface of propodeum, the latter with coarse punctures. Petiolar peduncle finely reticulate-punctuate. Gaster densely punctuate-reticulate; tergite of abdominal segments V, VI and VII finely and densely punctuate, slightly opaque, tergal margins smooth and shiny, slightly yellowish; sculpture slightly sparser on first gastral sternite, especially anteromedially. Antennal scapes finely rugo-reticulate. Coxae punctuate-foveate, other leg segments superficially rugo-reticulate.

Head oblong, lateral emarginate from eye height to posterolateral region and behind the head; posterior portion of head slightly depressed, projected posteriorly; vertexal margin with rounded corners, less divergent in the posterior portion than observed for B. manni, median portion largely concave. Occipital margin narrower than that of B. manni, cervical margin wide, lamelliform and conspicuously transversely carinate. Palp formula 2,2; palps strongly fused; maxillary palp slightly larger and wider than labial, with a sensillum; labial palp apically clavate, with two sensilla. Stipes subrectangular. Labrum lunate, arched laterally; round, anterior margin continuous. Man dibles triangular; in full-face view, lateral margins slightly concave; basal margin conspicuously concave leaving a wide clypeomandibular space; basal angle round, followed by about 18 denticles, slightly serrated and gradually decreasing in size along the masticatory margin; in lateral view, mandibular apex slightly curved ventrally. Clypeus lamellated laterally and on anterolateral portion; anterior margin medially concave. Compound eyes developed. Coarse ruga in front of eyes, projecting from the middle of antennal fossa limit and extending to head side like an arc. Antennal scape with slightly rounded lamellar basal angle, outer margin crenulate and lamellar. Antennal fossa deep. Antennal scrobe deep on anterior half, posterior and ventral limit weakly distinct. Mesosoma slender; lateral profile of promesonotal complex continuously convex, strongly sloping caudad; metanotal suture wide. Mesopleuron anteriorly bordered, interrupted at the meeting with a narrow epicnemial fossa. In lateral view, anterior portion of propodeum short and slightly oblique posteriorly, dorsal surface of propodeum slightly sloping posteriorly. Propodeal declivity laterally carinate and with strong transverse lamellar carina connecting the short, sharp and tapered propodeal projections. Opening of propodeal spiracle round. Metapleural gland bulla protruding, prominent; opening transverse and covered by cuticular lamella. Petiolar peduncle longitudinally carinate on its dorsal surface. In lateral view, petiole claviform, petiolar node obsolete, conspicuously low; dorsal margin bulging; postpetiole subcircular, subequal to petiolar node. Subpetiolar process extremely variable: from short anterior spiniform process followed or not by short spines to the most diverse combinations of bifid processes, lamella, simple spines and vestigial processes of different sizes. In dorsal view, petiolar node ogive-shaped; posterior margin of postpetiole convex, widely inserted to anterior concavity of gaster. Postpetiolar sternite conspicuously carinate anteromedially, prora present, lamellar and slightly darkened. Gaster with yellowish lamellar anterodorsal margin; anteroventral margin of the sternite keeled or carinate medially (this character is sometimes hindered by particle covering). Although it is not possible to notice a gastral sulcus like the one found on B. manni, the central longitudinal band of the first gastral tergite is entirely glabrous. Calcar of strigil pectinate. Meso- and metabasitarsi conspicuously long, about ¾ of tibial length. Tarsal claws simple. Sting apparatus (after Kugler, 1978): wide, spiracular plate ovoid, anterior apodeme subtriangular. Body shortly extended to medial connection. Spiracle small, near center of plate. Quadrate plate: apodeme and body narrow and reduced; anterodorsal corner with digitiform process, well sclerotized; plate gradually reduced ventrad, especially apodeme. Oblong plate not divided into preincision and post-incision; dorsal crest as wide as length of posterior arm; arm not on midline; transversely broad, anterior apodeme spatulate; ventral arm short and broad; fulcral arm narrow, continuously tapering from base; vertical. Gonostylus: sclerites well-defined; only trichoid and chaetoid sensilla present; proximal segment tapering from base. Triangular plate: elongated; prominent apicoventral process. Lancet: sword-shaped; single valve relatively large, but not very developed; sulcus converging to ventral crest. Sting: blade slightly longer than the sum of the lengths of the bulb and the valve chamber, gently curved upwards and moderately sclerotized; valve chamber slightly shorter than the sting bulb; sting base moderately arched and obliquely truncated in lateral view. Basal notch short and heavily arched; articular processes short and slightly directed to ventral margin. Sting bulb large; sides straight and gently converging. Furcula: T-shaped, extremities of lateral arms extending slightly over sting bulb.

Queen

Gyne (n=3). HL 1.35–1.40, HL2 1.0–1.44, HW1 1.06–1.14, MdL 0.90–0.91, SL1 1.15–1.18, SL2 1.13–1.18, PDL 0.14–0.15, A3L 0.05, AFL 0.45–0.48, FuL 1.16–1.26, EL 0.25, EW 0.23–0.24, LOD 0.08, MOD 0.06, OOD 0.37–0.38, ML 2.13–2.15, MSL 1.00–1.05, MSW 0.8–0.82, MLL 0.25–0.3, MLW 0.4–0.42, MfL 1.70–1.71, MtL 1.38, PH 0.32–0.42, PL 1.00–1.07, PW 0.3–0.42, PPW 0.52–0.57, GL 1.92–1.95, GW 1.32–1.35, TL 7.93–8.00, CI 77–84, CS 1.22–1.25, MCI 65–66, SI 103–105, ESI 21–22, SAI2 250–257, EI1 0.38–0.40, MTI 76–82, MLI 141–160, MFI 62–66, PTI 235–330. (In bold measurements influenced by accumulation of litter and soil particles on the integument).

Coloration and sculpture similar to conspecific workers; slightly larger size. Cephalic dorsum with three ocelli: median ocellus inserted at the height of posterior limit of compound eyes and lateral ocelli inserted slightly above. Head pilosity as in conspecific workers. Double layer of specialized pilosity on pronotum denser than in workers. Basal pilosity more sparsely present on the mesoscutum and mesoscutellum. Median portion of metanotum with a pair of long, clavate and suberect hairs, and four hairs on the basal layer with a plumose appearance.

Basal pilosity present on posterior corner of mesoanepisternum, just below forewing insertion. Ventral and posterior limits of mesokatepisternum with basal pilosity, as well as ventral portion of metakatepisternum. Pilosity on rest of body with shape and configuration similar to conspecific workers. Mesoscutum with irregular longitudinal rugae, interposed with rugulae forming foveae of different sizes. Mesoscutellum irregularly rugo-foveate. Mesopleuron irregularly rugose, sparse punctuation within foveae formed by these rugae. Anapleural sulcus granular, submedian transverse carina present. Anterior portion of petiolar peduncle finely reticulate. Lateral of mesoscutellum striate-reticulate. Metanotum finely reticulate. Gastral sculpture stronger impressed than on workers. Sculpture of other regions as in conspecific workers. In dorsal view, humeral angles strongly projected, dividing the pronotum into two regions. Mesoscutum slightly cuneiform, anteriorly round, with a short, smooth and subopaque longitudinal carina on its anteromedial portion; slightly cuneiform; posterior margin broadly convex at the meeting with the scutoscutellar suture. Notauli and parapsidal lines indistinct; parapsides slightly deep, subreniform; tegulae narrow, elongated and somewhat translucent, apical margin round. Pre-scutellum narrow; axillae projected posteriorly, round and slightly depressed. Sulcus scutoscutellar well-marked, with transverse costulae. Mesoscutellum trapezoidal, posterior limit concave; in lateral view, one the same level as or just below the scutum. Anapleural sulcus wide, matte, and transversal to body axis. Sting developed. Forewing type 1; hindwing with 5–8 submedian hamuli.

Intercastes. Several individuals, ranging from worker-like specimens bearing:

  • slightly bigger compound eyes;
  • minute ocelli;
  • vestigial mesoscutum and few other modifications on mesosoma;
  • mesoscutum and mesoscutellum present, although undeveloped;
  • scutoscutellar sulcus not impressed.
  • wing fossae and rudiments (i.e. brachyptery);
  • transscutal articulation inconspicuous, covered by integumental sculpture;
  • axillae vestigial, seen as very short lamellae;
  • tegulae vestigial;
  • metanotal suture more impressed than in the regular conspecific workers;
  • metanotum, as transversal arch with indistinct posterior limit, delimited by strongly marked longitudinal carina from the metanotal suture;

to gyne-like individuals, with:

  • rudiments of forewing articulation and pteralia;
  • vestigial wing buds;
  • fully-developed wing fossae, less impressed than on conspecific gynes;
  • vestigial parapsides, shorter than on true gynes;
  • transscutal suture, somewhat flat;
  • scutoscutellar sulcus, slightly narrower than in the conspecific gynes;
  • axillar carina, axillae slightly shorter than on true gynes and with specialized pilosity on the posterolateral corner; *scutellum, depressed as in the conspecific gynes but shorter;
  • metanotum like in the conspecific gynes, although slightly shorter, carinate dorsomedially;
  • dorsal subplumose pilosity similar to conspecific gynes
  • tegulae present, although shorter than the conspecific gynes;
  • metanotal suture deeply impressed, presenting broad longitudinal carina;
  • axillary sclerites;
  • rudimentary forewings, hindwings sometimes still attached to body.

Male

(n=2). HL 0.91–1.00, HW1 0.90–0.93, HW2 1.04–1.08, MdL 0.55–0.56, SL2 0.20–0.23, PDL 0.13–0.15, A3L 0.58–0.63, AFL 0.55–0.63, EL 0.34, EW 0.30, LOD 0.09–0.1, MOD 0.09, OOD 0.31–0.33 ML 1.88–1.93, MSL 1.03–1.04, MSW 0.72–0.75, MLL 0.3, MLW 0.42–0.45, MfL 1.8, MtL 1.38, PH 0.28–0.29, PL 0.90–0.95, PW 0.31–0.33, PPL0.39–0.43, PPW 0.39–0.44, GL 1.58–1.60, GW 1.15–1.18, TL 6.21–6.45, CI 92–98, CS 0.91–0.96, MCI 55–61 SI 22–24, ESI 150–168, SAI 34–36, SAI2 32–40, EI1 0.66–0.70, EI2 86–86, MTI 69–73, MLI 141–

Slightly smaller than conspecific gyne. Coloration dark brown to black; propodeal lobes and disc of first gastral tergite sometimes testaceous; appendages light brown to yellowish. Wigs yellowish, amber or brown. Dorsum and apex of mandibles with long, fine yellow hairs, semierect to subdecumbent, longer on the latter. Head with two main types of hair: medium, yellow and fine, subdecumbent; primarily on frontal disc of clypeus; and long yellowish or brown, sometimes apically curved and primarily on frons, along the genal carina, on the vertexal margin, and ventral surface. The latter type is widely present throughout the body: on mesosomal dorsum, waist and gaster, coxae and mesokatepisternal suture; especially long on the lateral margin of pronotum and dorsum of petiole. Antennomeres with short yellowish appressed setae. Legs with semierect setae sparsely distributed between short decumbent to decumbent setae.

Body uniformly punctuate-reticulate, minor changfes in diameter and degree of impression. Apical portion of mandibles smooth and shiny. Irregular longitudinal rugae present on neck to faintly on the vertex margin, close to occipital carina. Irregular transverse rugae on dorsum of mesoscutellum; on the side of pronotum and propodeum. Mesokatepisternum irregularly carinate-rugose.

Head piriform; occipital margin wide and lamellar. Palp formula 1,1, palps apically subclavate and subequal in size; maxillary palp slightly wider than labial; apexes of palpi with long, filiform sensilla. Stipes subrectangular. Labrum trapezoidal; basal region transversely striated; distal margin weakly concave; sides angled; approximately 10 long and erect setae present. Mandibles triangular, about twice as long as wide and gently curved apically; masticatory margin with 11–12 conical teeth, basal tooth bifid or subquadrate, apical tooth slightly falcate. Clypeus with convex central disc, slightly elevated; lateral regions depressed; anterior margin lamellar and slightly convex. Genal carina present, extending posteriorly almost to upper margin of compound eyes. Longitudinal carina on frons, with or without anteroposterior sulcus; keeled medially and extending posteriorly as a line to median ocellus. Antennal arch expanded medially in posterolateral lobe, hiding the antennal bulb in full-face view. Pedicel longer than wide, third antennomere about six times longer than pedicel. Eyes large and globular, protruding from cephalic capsule; posterior margin emarginate. Ocelli pearl-like and projected.

In dorsal view, mesoscutum keel-shaped, cuneiform; in lateral view pronotum with triangular side flaps. Shiny subtriangular carina present on the anteromedial region of mesoscutum, extending as a line until near the dorsal region, where it continues as a carina until meeting the notauli. Anterior region of mesoscutum narrow and slightly higher and obliquely convex in profile. Parapsidal lines shiny; curved anteriorly, subparallel and directed anterolaterally to the parascutal flange. Parapsides broad, deep and oval. Transscutal suture slightly convex. Axillae protruding, strongly curved posteriorly and downwards; spear-shaped. Anapleural sulcus broad, strongly imprinted (mesoanepisternum strongly elevated to mesokatepisternum); scrobiculate. Scutoscutellar sulcus broad, about half the length of mesoscutellum; longitudinally carinate and with posteromedial transverse carina. Mesoscutellum subrectangular; posteromedially depressed; posterior margin strongly concave and depressed. In dorsal view, metanotum distinct, posterior margin projected; lateral margins lamellar. Propodeum armed with triangular projections; carinate as in conspecific females. Propodeal lobes auricular. Calcar of strigil pectinate. Tarsal claws simple (see comments); arolia present, short. Petiole long, similar to conspecific females; in lateral view, claviform; in dorsal view, petiolar spiracle projected; subpetiolar projections absent. Postpetiole short; in lateral view, dorsally convex; spiracle projected; sternite with transverse lamellar prora close to anterior margin; in dorsal view, only slightly wider than the petiole. Forewing type 1, hindwings with five submedian hamuli.

Larva

(description updated and modified from Wheeler & Wheeler 1977, 1980). Length through spiracles 5.0 mm; profile pogonomyrmecoid: larger diameter near the middle of the abdominal region, thorax slender than abdominal region; curved ventrally. Anus ventral, opening weakly convex, anal flap present. Spiracles small. Integument of ventral region densely covered by spinules arranged in transverse rows. Pilosity moderate, hairs short to long; usually flexuous and denticulate. Cranium slightly subcordiform, occipital margin with median impression; antennae minute, with 3 spinulate sensilla. Clypeus protruding. Labrum bilobed; ventral surface densely spinose; anteroventral margin of each lobe with ca. 6 spinose sensilla. Mandibles ectatommoid, long and narrow, medially curved; subapical tooth slightly anterior to the plane of a large apical tooth; anteroventral margin densely covered by spinules in short, arcuate subtransverse rows. Maxillae parabolic, dorsum with 5 setae, apex densely spinose; maxillary palps galeae digitiform, subequal in size and diameter; maxillary palp with 5 sensilla: two apical, encapsulate, two lateral with one spinule, and a subapical, spinulose; galeae with two spinulose apical sensilla. Labium densely spinulose; spinules arranged in short arcuate rows; labial palp papillary, with five apical sensilla (two encapsulated and three spinulate); a short, isolated sensillum on each side of the opening of sericeous gland; opening transversal. Hypopharynx densely spinulose; long spinules arranged in numerous subparallel rows.

Type Material

BRAZIL: Amazonas: Ega (=Tefé): no data, no collector (Meranoplus singularis, one worker—lectotype) [MNH] (examined).

Etymology

From Latin, singularis, different, rare, unusual. Smith possibly named this taxon—the first described for the genus—based on its peculiar morphology.

References

References based on Global Ant Biodiversity Informatics

  • Brandao, C.R.F. 1991. Adendos ao catalogo abreviado das formigas da regiao neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412.
  • Brown W. L. J. 1974. A supplement to the revision of the ant genus Basiceros (Hymenoptera: Formicidae). Journal of the New York Entomological Society. 82: 131-140.
  • Brown W. L., Jr., and W. W. Kempf. 1960. A world revision of the ant tribe Basicerotini. Stud. Entomol. (n.s.) 3: 161-250.
  • Fernández, F. and S. Sendoya. 2004. Lista de las hormigas neotropicales. Biota Colombiana Volume 5, Number 1.
  • Franco W., N. Ladino, J. H. C. Delabie, A. Dejean, J. Orivel, M. Fichaux, S. Groc, M. Leponce, and R. M. Feitosa. 2019. First checklist of the ants (Hymenoptera: Formicidae) of French Guiana. Zootaxa 4674(5): 509-543.
  • Gibernau M., J. Orivel, J. H. C. Delabie, D. Barabe, and A. Dejean. 2007. An asymmetrical relationship between an arboreal ponerine ant and a trash-basket epiphyte (Araceae). Biological Journal of the Linnean Society 91: 341-346.
  • Kempf, W.W. 1972. Catalago abreviado das formigas da regiao Neotropical (Hym. Formicidae) Studia Entomologica 15(1-4).
  • Medina U. C. A., F. Fernandez, and M. G. Andrade-C. 2010. Insectos: escarabajos coprofagos, hormigas y mariposas. Capitulo 6. Pp 197-215. En: Lasso, C. A., J. S. Usma, F. Trujillo y A. Rial (eds.). 2010. Biodiversidad de la cuenca del Orinoco: bases científicas para la identificación de áreas prioritarias para la conservación y uso sostenible de la biodiversidad. Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, WWF Colombia, Fundación Omacha, Fundación La Salle e Instituto de Estudios de la Orinoquia (Universidad Nacional de Colombia). Bogotá, D. C., Colombia.
  • Probst R. S., B. D. Wray, C. S. Moreau, and C. R. F. Brandao. 2019. A phylogenetic analysis of the dirt ants, Basiceros (Formicidae: Myrmicinae): inferring life histories through morphological convergence. Insect Systematics and Diversity 3(4): 1–12.
  • Probst da Silva R. 2015. Revisao taxonomica e analise filogenetica de Basiceros Schulz, 1906 (Formicidae, Myrmicinae, Basicerotini). Master Thesis Museu de Zoologia da Universidade de Sao Paulo. 263 pages.
  • Weber N. A. 1950. New Trinidad Myrmicinae, with a note on Basiceros Schulz (Hymenoptera, Formicidae). American Museum Novitates 1465: 1-6.
  • Wheeler W. M. 1916. Ants collected in British Guiana by the expedition of the American Museum of Natural History during 1911. Bulletin of the American Museum of Natural History 35: 1-14.
Retrieved from "https://antwiki.org/wiki/index.php?title=Basiceros_singularis&oldid=714642"