Odontomachus xeta, França & Fernandes & Bravo, 2024

França, Eder Cleyton Barbosa, Fernandes, Itanna Oliveira & Bravo, John Edwin Lattke, 2024, Looking at upside-down ants: Taxonomic revision of the Neotropical species of Odontomachus Latreille, 1804 (Hymenoptera: Formicidae: Ponerinae), Zootaxa 5502 (1), pp. 1-166 : 56-87

Odontomachus biolleyi Forel, 1908 ( Fig. 23-A , 59 and 60 )

Odontomachus biolleyi Forel, 1908: 35 (☿ and ♀) Wheeler & Wheeler, 1952: 651 (larvae).

Type specimens: Syntype [Images]. COSTA RICA: Manglares, Embouchure du Jèsus Maria [Mangrove, Jesus Maria river mouth], 128, (Pac.) [Pacific coast] Bois pourri [in Rotten wood], I tg06, Biolley, P. col., CASENT0907425 1☿ [ MHNG] .

Note: Specimens tagged COLUMBIEN[ COLOMBIA]: Pandi. östl[ich], [east], Odontomachus biolleyi For. [el] subsulcatus V[Viehmeyer. H. col.], Coll Viehm., GBIF-D/FoCol052, FOCOL1052 1☿ / GBIF-D/FoCol053, FOCOL1053 1☿ / GBIF-D/FoCo1054, FOCOL1054 1☿ [ ZMHB] were never published as subspecies of O. biolleyi by Viehmeyer, therefore this name is considered as nomen nudum .

Etymology: In honor to Paollo Biolley (1862-1908), a Swiss naturalist who collected the type specimens of this species.

Diagnosis: (☿) Small light brown ants (TL= 7.9-9.4). Petiolar node conical, anterior and posterior face almost straight; petiolar spine reduced to a short blunt projection. (g#) Not examined. (♂) Unknown.

Worker

Syntype measurements: EL 0.4, HL 2.1, HoW 1.8, HvW 1.2, HW 1.5, ML 1.4, SL 2.2, PnW 1.1, WL 2.7, FL 2.2, PTH 0.9, PTL 0.4, PTW 0.5, GL 2.8, TL 9.55. CI 0.72, MI 0.67, PtI 2.16, SI 1.07, VI 0.81.

Non-type measurements: EL 0.3, HL 1.7, HoW 1.3, HvW 1.0, HW 1.1, ML 0.8, SL 1.5, PnW 0.8, WL 2.6, FL 1.6, PTH 0.8, PTL 0.3, PTW 0.3, GL 2.5, TL 7.9. CI 0.64, MI 0.47, PtI 2.66, SI 0.88, VI 0.90 (n= 1).

Head. Vertex trapezoidal, wider than long in frontal view; with regular longitudinal striae. Posterior margin concave medially; occipital carina not forming nuchal collar. Cephalic constriction conspicuous. Frontal lobes striated. Ocular bridges posteriorly forming arc. Eye relatively large (EL> 0.4); rounded, posterior margin rounded. Clypeus smooth and shining with inconspicuous piligerous punctuation on median portion. Malar area smooth and shining in latero-oblique view.

Mandible. Shorter than anterior head portion. External margin slightly convex. Masticatory margin with denticles that serially increase in size apically. Apical teeth acute. Palp formula 4,3.

Antenna. Scape surpassing occipital corner more than pedicel length.

Mesosoma. Pronotum in lateral view rounded, dorsal face convex; neck well developed anteriorly in dorsal view; lateral margin rounded; central disc of pronotum with regular longitudinal striae, lateral striae forming concentric circles or arcs directed anteriorly. Propleuron smooth and shining. Mesonotum almost as long as wide; with regular transverse striae slightly effaced centrally. Mesopleuron with vestigial carina on anteroventral portion; anterior portion with fine irregular transverse striae curved dorsal-anteriorly, median and posterior portion smooth and shining. Mesometanotal sulcus well-marked, scrobiculate, curved anteriorly. Metanotum vestigial. Metapleural gland bulla with regular transverse striae on ventral portion. Propodeum in lateral view straight; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process open, cuticle border forming pair of lateral projections; with micro-sculpturing.

Petiole. Sessile. Node conical, anterior and posterior margins slightly convex. Spine vestigial forming short blunt projection. Fine, irregular and transverse striae limited to ventral portion, gradually becoming imbricate and smooth and shining dorsally. Subpetiolar process wider than long keel-shaped; tip acute; posterior portion concave.

Gaster. First tergum almost higher than long; anterior and dorsal margin meeting in an obtuse angle; dorsal face convex; dorsal face of all terga smooth and shining.

Color and size. Body light brown. Legs and antennae yellowish. Relatively small ants.

Pilosity. Dense, conspicuous and short pubescence spread over the body, separated each other less than their length. Pubescence on mandible sparser than body surface. Pubescence on petiole shorter. Pubescence on gaster dense, separated each other about half of its length. Short hairs on anterior margin of procoxa; pronotum and dorsum of gastral terga, smaller than pro-coxal width.

Natural history: Little is known about this species. Vásquez-Bolaños (2011) reports the occurrence of this species in Tabasco, Mexico.According to the original description ( Forel, 1908), this species inhabits mangroves. The type-locality is also the southernmost record. Considering the few specimens present in collections, and the records on coastal areas, O. biolleyi may have a restricted distribution along the Pacific Coast of Central America. We need to know its biology to understand if there is habitat specialization and the vulnerability state of its populations.

Comments: Odontomachus biolleyi is a unique small, and yellowish species that can be quickly recognized by its unique petiole shape. The anterior and posterior faces of the petiole are convex and the spine is reduced to a blunt projection. The gastral terga, which is smooth and shining, associated with the small size and the yellowish color makes this species very similar to O. panamensis . The petiolar node is enough to separate both. Odontomachus panamensis has the petiolar spine well-developed and the anterior margin of the node is straight to slightly concave, whereas O. biolleyi has the petiolar spine short and the anterior margin of the node convex. Furthermore, O. biolleyi does not have rounded projections on the anterior ventral portion of mesopleuron as in O. panamensis .

It was not possible to examine the gyne syntype of O. biolleyi . Considering the variation in the petiole shape between workers and gynes of Odontomachus , the anterior node face of the gyne might be less convex, but the reduced spine is probably similar to the workers. The aforementioned worker differences should be enough to separate them from gynes of O. panamensis .

The type specimens of O. biolleyi subsulcatus correspond to O. erythrocephalus . The reddish head contrasting with the almost black, body seen in AntWeb images FOCOL1052, FOCOL1053 and FOCOL1054 made it possible to recognize this misidentification. Because O. biolleyi subsulcatus is a nomen nudum it is not available as a junior synonym of O. erythrocephalus nor of O. biolleyi .

Material examined: 1☿. MEXICO: Yucatán: Mérida (1☿) .

Odontomachus biumbonatus Brown, 1976 ( Fig. 22-A , 41-B , 61 , 62 , 63 and 64 )

Odontomachus biumbonatus Brown, 1976: 131 (☿ and ♀).

Type specimens: Paratypes. BRASIL [ BRAZIL]: Amazonas , Rio [river] Tarumã, High Falls, M- /03, 02.viii.1962, Brown, W. L. col., MZSP77538 1☿ [ MZSUP] .

Paratype. BRASIL [ BRAZIL]: Pará, Icoarací. B- 22, 03.viii.1962, Brown, W. L. col., MZSP 77539 1☿ / MZSP 77540 1☿ [ MZSUP] . EQUADOR [ ECUADOR]: Limon Cocha [Limoncocha] & vic[inity], Sep-Nov. 64 [ixxii.1964], Hermann. H. R. col., MZSP 77541 1☿ / MZSP 77542 1☿ / MZSP 77543 1☿ / MZSP 77544 1☿ [ MZSUP]/ [Images] BMNH (E) 1014007, CASENT0900610 1☿ [ BMNH] . EQUADOR [ ECUADOR]: Prov [ince] Napo, Limoncocha , 00°24’S 76°36’W, #140, 12.vii.1970, Kazan. P. L. col., MZSP 77545 1☿ [ MZSUP] . PERU: Cuzco Dep [artament], Quincemil. ix.1962, Pena. L. col., MZSP 77546 1☿ [ MZSUP] . PERU: [Huánuco], Tingo Maria & vic[inity], 09-12.iii.1967, Brown, W. L. & Sherbrooke, W. col., MZSP 77547 1☿ / MZSP 77548 1☿ [ MZSUP] .

Etymology: From the Lati words bi = two + umbonatus = knob, round ancient shield with a projecting point in the center; referring to the posterior portion shape of the petiolar node.

Diagnosis: (☿) Vertex rectangular. Eyes elliptical, longer than large with posterior margin acute. Propleuron smooth and shining, transverse striae limited to external margin. Metasternum with irregular longitudinal striae; metasternal process open, posterior cuticle border forming pair of acute lobes deeply impressed anteriorly. Petiolar node cylindrical. (♀) Vertex, eyes and metasternum as in worker. (♂) Body color dark brown with lighter areas. Mesoscutellum in antero-dorsal view with dorsal margin concave. Posterior face of propodeum with concentric striae parallels to median longitudinal carina. Metasternum as in worker.

Worker

Paratype measurements: EL 0.41, HL 2.46-3.45, HoW 1.92-2.70, HvW 1.61-2.23, HW 1.71-2.37, ML 1.51-1.97, SL 1.98-2.88, PnW 1.12-1.35, WL 2.74-3.6, FL 2.39-3.18, PTH 0.96-1.26, PTL 0.52-0.7, PTW 0.32-0.42, GL 2.44- 3.22, TL 9.67-12.94. CI 0.66-0.70, MI 0.42-0.62, PtI 1.71-2.4, SI 0.81-0.87, VI 0.95-1.0.

Non-type measurements: EL 0.40, HL 2.9-3.4, HoW 2.2-2.7, HvW 1.9-2.4, HW 2.0-2.4, ML 1.4-2.0, SL 2.5- 2.9, PnW 1.2-1.5, WL 3.4-3.9, FL 2.9-3.2, PTH 1.1-1.4, PTL 0.5-0.7, PTW 0.4-0.5, GL 2.8-3.8, TL 11.67-13.2. CI 0.66-0.7, MI 0.42-0.62, PtI 1.71-2.4, SI 0.81-0.87, VI 0.95-1.0 (n= 12).

Head. Vertex rectangular, wider than long in frontal view; with regular longitudinal striae. Posterior margin concave medially; occipital carina not forming nuchal collar. Cephalic constriction conspicuous. Frontal lobes striated. Ocular bridges posteriorly forming arc. Eye relatively large (EL> 0.4); elliptical, posterior margin acute. Clypeus with inconspicuous longitudinal striae on median portion posteriorly. Malar area in latero-oblique view with irregular transverse to oblique striae on anterior portion, posterior portion smooth and shining.

Mandible. Almost as long as anterior head portion. External margin slightly convex. Masticatory margin with denticles that serially increase in size apically. Palp formula 4,3.

Antenna. Scape surpassing occipital corner about pedicel half-length or less.

Mesosoma. Pronotum in lateral view angulate, dorsal margin slightly convex; in neck well developed anteriorly dorsal view; lateral margin forming obtuse angle posteriorly; central disc of pronotum with longitudinal to diagonal striae forming spiral-like shape, lateral striae forming concentric circles or transverse ellipses. Propleuron with fine transverse striae on lateral portion, central portion smooth and shining. Mesonotum wider than long, slightly concave medially; with regular transverse striae. Mesopleuron with rounded carina on anteroventral portion; anterior portion with fine regular transverse striae, median and posterior portion smooth and shining. Mesometanotal sulcus well-marked, scrobiculate, slightly curved anteriorly.Metanotum as long as notopropodeal sulcus; with irregular transverse striae. Metapleural gland bulla with transverse striae effacing posteriorly. Propodeum in lateral view irregular with two shallow impressions; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process open, cuticle border forming acute pair of lobes converging medially deeply impressed anteriorly; completely dense punctate, with irregular longitudinal striae.

Petiole. Sessile. Node cylindrical, ventral portion slightly wider than dorsal portion; posterior face concave medially forming two blunt lateral projections. Spine acute, straight to slightly curved posteriorly. Regular to irregular oblique striae on ventral portion of lateral face extending posteriorly. Subpetiolar process wider than long keel-shaped; tip acute; posterior portion concave.

Gaster. First tergum almost higher than long; anterior and dorsal margin meeting in an obtuse angle; dorsal face convex; dorsal face of all terga imbricate, almost smooth and shining.

Color and size. Body brown to dark brown almost black. Legs and antennae brown to light brown. Relatively large to medium size ants.

Pilosity. Hook-shaped, dense, conspicuous and short pubescence on head, mesosoma and petiole, separated each other about their length. Pubescence on mandible sparser than body surface medially. Pubescence on petiole limited to anterior face extending to lateral faces. Pubescence on gastral terga sparse, separated each other more than its length. Short hairs on anterior face of pro-coxa smaller than coxal width. Pronotum with three or four pairs of long, curved erect hairs longer than maximum pro-coxa width. Long subdecumbent hairs on posterior 3/4 of gastral terga directed posteriorly, as long as pronotum hairs.

Gyne

Non-type measurements: EL 0.6, HL 3.4, HoW 2.7-2.8, HvW 2.3-2.4, HW 2.4-2.5, ML 2.1, SL 2.8-3.0, PnW 1.8- 1.9, WL 4.2-4.3, FL 3.4-3.3, FWL 8.5, PTH 1.6-1.7, PTL 0.7, PTW 0.70, GL 4.4-4.7, TL 14.9-15.1. CI 0.75-0.77, MI 1.03-1.07, PtI 2.2-2.4, SI 0.64-0.70, VI 1.14-1.19 (n= 2).

Mesosoma. Pronotum slightly longer than high in lateral view, dorsal margin concave forming obtuse angle, separating in anterior and dorsal margin; lateral margins converging anteriorly forming a neck in dorsal view; pronotal dorsum with regular transverse striae, becoming irregular posteriorly, slightly curved posteriorly on lateral face. Subalar area conspicuous with pronotum; with irregular striae. Mesoscutum anterior and dorsal margin forming single convexity in lateral view; with regular longitudinal striae in dorsal view; striae between parapsidial line and parascutal area oblique, directed medially; longitudinal carina on medial line standing out from striae. Parapsidial line curved, well-marked. Parascutal area smooth and shining. Notopropodeal sulcus scrobiculate. Axilla with fine longitudinal striae effacing laterally. Mesoscutellum smooth and shining with longitudinal carina on posterior portion. Metascutellum smooth and shining with longitudinal carina.

Wing. Color brown translucid. Forewing ML1 curved. RsL1 straight; shorter than Rs+M. RSL2-3 sinuous. Rs+M and ML2 forming single slightly curved line, not forming angle with RsL2-3. Vein cu-a not reaching M+Cu ML1 angle by almost its half-length. Hindwing 1rs-m vein curved. 12 hamuli.

Petiole. Conical node, anterior face straight to slightly concave, dorsal portion of posterior face rounder than worker petiole. Petiolar spine robust.

Pilosity. Pubescence on mesosoma strongly curved, dense separated each other less than its length. Pubescence on mesoscutellum less dense. Pronotum and mesoscutellum with pair of long hair curved posteriorly.

Male

Non-type measurements: EL 0.77, HL 1.08, OW 0.15, OES, 0.34, IOW 0.18, WL 3.20, FWL 6.10, PTH 0.90, PTL 0.60, PTW 0.50, GL 2.90, TL 7.18. PtI 1.50 (n= 1).

Head. Palp formula 4,3. Lateral ocelli surpassing posterior margin; posterior margin between lateral ocelli slightly concave, not reaching median ocellus.

Mesosoma. Pronotal dorsum smooth and shining with sparse punctures next to posterior margin; with sparse and effaced micro sculpture on ventral and posterior portion in lateral view. Propleuron with micro sculpture. Mesoscutum anteriorly with effaced fine, transverse striae, dorsum with longitudinal median carina, inconspicuous longitudinal regular striae next to it and parapsidial lines. Axilla with sparse and fine longitudinal striae, micro sculpture present between them. Mesoscutellum medially concave; with regular sparse longitudinal striae anteriorly, gradually effacing posteriorly. Metascutellum with dense micro sculpture with longitudinal carina. Anepisternum with inconspicuous fine irregular striae on anterior portion gradually becoming smooth and shining. Katepisternum with dense micro sculpture of reticulate aspect. Metapleuron with fine curved striae on central portion gradually becoming coarse rugae on anterior and posterior portions. Metepisternum with coarse transverse striae anteriorly and fine irregular striae on central and posterior portions. Metapleuron and propodeum separated by sulcus slightly scrobiculate. Propodeal dorsum with fine irregular longitudinal striae, dense micro sculpture of reticulate aspect between them; dorsal and posterior face of propodeum delimitated by short coarser striae; posterior face of propodeum with median irregular carina and effaced, fine irregular concentric striae.

Wing. Light brown translucid. Hamuli varying between 8 and 9.

Petiole. Sessile; dorsal portion acute, slightly concave laterally; with dense micro sculpture of reticulate aspect limited to ventral portion under spiracle level. Sternum concave posteriorly forming a blunt lobe posterior to subpetiolar process.

Color and size. Entire body dark brown. Mesoscutum with darker area posteriorly. Dorsal portion of petiole lighter. Gastral terga with posterior portion gradually becoming lighter. Relatively medium size.

Pilosity. Head, mesosoma and gaster with dense appressed pubescence. Pronotum with two thin erect hairs on posterior portion. Pubescence on posterior face of petiole absent. Thin, erect short hairs on posterior portion and gaster segments I and II, hairs on segments III, IV and V almost two times longer.

Natural history: Little is known about the biology of O. biumbonatus . It is known to occur in humid forests ( Brown, 1976) and there are records of specimens collected in termite nests (label data). Odontomachus biumbonatus possibly is a cryptic predator due to its reduced eyes compared to the other Odontomachus species with massive heads, or perhaps, this species is more active at night. This could explain the sparse records of this species that might be more frequent and widely distributed in the Amazonian region ( Fig. 65 ).

Comments: Among the Amazonian species, O. biumbonatus is quickly recognized by the cylindrical petiolar node and the rectangular vertex. The only species that shares these characters is O. xeta sp. nov. Odontomachus biumbonatus has the metasternal process open, forming a pair of acute deeply impressed lobes and O. xeta sp. nov., has the metasternal process closed, forming a bilobate projection. In addition, O. biumbonatus is widely distributed in the Amazonian while O. xeta sp. nov. distribution is restricted to the Atlantic rain forest. Although no male associated with a worker or gyne was examined, the petiole shape and the metasternal process of the male specimen are enough to recognize it as O. biumbonatus . This male specimen has one less hamuli on the left wing and the same was observed in the male of O. erythrocephalus . The propodeal sculpture is also diagnostic for both castes as O. biumbonatus has concentric striae on the posterior face and O. xeta sp. nov. has transverse striae limited to the posteroventral portion.

Material examined: 28☿, 4♀ and 1♂. BRAZIL: Acre: [Rio] Iquiri (1☿) . Amapá: Serra do Navio (1♀) .

Amazonas: AM 00, Km 26 (3☿) ; Manaus (2☿) . Mato Grosso: Diamantino (1☿) ; Diauarum (1♀) . Pará: Benevides (1☿) ; Belém (7☿) ; Carajás (2☿) . ECUADOR: Napo: Limoncocha (4☿, 1♂) . PERU: Cusco: Estación Biológica Villa Carmen (1♀) ; [Huanuco]: Rio Sán Alejandro (1☿) . Puerto Maldonado (6☿, 1♀) .

Odontomachus bradleyi Brown, 1964 ( Fig. 18-B , 30-B , 65 , 66 , 67 )

Odontomachus bradleyi Brown, 1976: 133 (☿).

Type specimens: Paratype. PERU: Huacapistana , 03 June [03.vi].1920, Bradley, J. C. col., #535, MZSP 77564 1☿ [ MZSUP] .

Etymology: In honor to James Chester Bradley (1884-1975) an American entomologist who collected the type specimens of this species.

Diagnosis: (☿) Rectangular vertex almost long than wide striated longitudinally. Central disc of pronotum with longitudinal striae, external striae forming concentric circles. Petiole sessile, angulate node, anterior face shorter than subpetiolar process, dorsal face longer than petiole length. (♀) Unknown. (♂) Unknown.

Worker

Paratype measurement: EL 0.46, HL 3.4, HoW 2.46, HVW 2.03, HW 2.13, ML 1.94, SL 3.4, PnW 1.37, WL 4.02, FL 3.7, PTH 1.45, PTL 0.72, PTW 0.51, GL 3.88, TL 13.96. CI 0.62, MI 0.57, PtI 2.01, SI 1.0, VI 0.95.

Non-type measurements: EL 0.4-0.5, HL 3.2-3.8, HoW 2.2-2.6, HVW 1.8-2.1, HW 2.0-2.4, ML 1.9-2.1, SL 3.0-3.4, PnW 1.2-1.5, WL 4.0-4.5, FL 3.4-3.9, PTH 1.5-1.8, PTL 0.7-0.8, PTW 0.4-0.5, GL 3.4-3.8, TL 13.4-14.9. CI 0.61-0.63, MI 0.54-0.61, PtI 1.87-2.28, SI 0.86-0.97, VI 0.87-0.91 (n= 4).

Head: Vertex rectangular to trapezoidal in frontal view, wider than long, slightly narrow posteriorly; with regular longitudinal striae diverging posteriorly. Posterior margin concave medially; occipital carina not forming nuchal collar. Cephalic constriction conspicuous. Frontal lobes striate, striae effaced anteriorly. Ocular bridges posteriorly forming angle. Eye relatively large (EL> 0.4); rounded, posterior margin rounded. Clypeus smooth and shining on median portion. Malar area smooth and shining in latero-oblique view.

Mandible: Almost as long as anterior head portion. External margin slightly convex. Masticatory margin with denticle directed apically that serially increase in size; pre-apical tooth robust standing out forming blunt projection. Palp formula 4,4.

Antenna: Scape surpassing occipital corner by more than pedicel length.

Mesosoma: Pronotum in lateral view rounded, dorsal face convex; in dorsal view, neck well developed anteriorly; lateral margin rounded slightly angulate posteriorly; central disc of pronotum with regular longitudinal striae, lateral striae forming concentric circles. Propleuron with inconspicuous longitudinal striae converging medially. Mesonotum with regular transverse striae. Mesopleuron carina on anteroventral portion thin, not forming projection; anterior portion with regular transverse striae, median and posterior portion smooth and shining. Mesometanotal sulcus well-marked, smooth and shining to slightly scrobiculate. Metanotum as long as half-length of mesonotum; with irregular transverse striae; posteriorly constricted on laterals around metanotal spiracles. Metapleural gland bulla with transverse striae. Propodeum in lateral view slightly concave on middle length; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process open, cuticle border forming lateral round lobes; regular transverse striae on anterior portion, central portion smooth and shining.

Petiole: Sessile. Node angulate, anterior margin meeting dorsal margin in a round obtuse angle, anterior margin shorter than subpetiolar process; dorsal margin longer than petiole length continuous to petiolar spine. Spine robust, long, straight to slightly curved posteriorly as long as petiole half-height. Regular transverse striae on dorsal face gradually becoming oblique on lateral face effacing posteriorly. Subpetiolar process longer than wider; tip rectangular to blunt; posterior portion not concave.

Gaster: First tergum usually longer than higher; anterior and dorsal margin meeting in a slightly straight surface not forming an angle. dorsal face of all terga imbricate.

Color and size: Body dark brown to nut-brown. Gastral terga posteriorly with narrow strip light brown. Legs and antennae light brown to yellowish. Relatively large ants.

Pilosity: Scattered short pubescence spread over the body, separated each other by more than its length. Gaster with dense pubescence separated each other by less than its length. Short hairs on anterior portion of procoxa smaller than coxae width; two or three pairs of short hairs on pronotum, as long as procoxa hairs. Short subdecumbent hairs on posterior 2/3 of gastral terga as long as pronotum hairs.

Gyne

Non-type measurements: EL 0.6, HL 3.7, HoW 2.8, HvW 2.1, HW 2.4, ML 2.2, SL 3.4, PnW 2.0, WL 4.5, FL 3.9, FWL 10.0, PTH 2.1, PTL 0.9, PTW 0.6, GL 4.8, TL 16.1. CI 0.64, MI 0.59, PtI 2.3, SI 0.91, VI 0.87 (n= 1).

Mesosoma. Pronotum almost longer than high in lateral view, dorsal margin straight; lateral margins converging anteriorly forming a neck in dorsal view; with regular transverse striae forming angles on transition between dorsal and lateral face. Subalar area separated from pronotum by sulcus; striae irregular and finer than pronotum. Mesoscutum anterior and dorsal margins meeting in convex surface, form an almost rounded right angle; slightly wider than long in dorsal view; with regular longitudinal striae, striae on lateral portion curved posteriorly and converging; striae between parapsidial line and parascutal area oblique, directed medially. Parapsidial line curved, well-marked. Parascutal area smooth and shining. Notopropodeal sulcus with regular longitudinal striae forming pits.Axilla with regular longitudinal striae. Mesoscutellum slightly concave on middle line; with regular longitudinal striae with longitudinal carina. Metascutellum with effaced fine and irregular striae converging medially on anterior portion and with longitudinal carina.

Wing. Color dull light brown, darker on areas closer to veins. Forewing ML1 curved. RsL1 slightly curved; almost as long as Rs+M. RSL2-3 slightly sinuous. ML2 almost as long as Rs+M. Rs+M and ML2 forming single slightly curved line, not forming angle with RsL2-3. Vein cu-a not reaching M+Cu ML1 angle by more than its half-length. Hindwing 1rs-m vein straight. 9 hamuli.

Petiole. Angulate node, anterior face meeting dorsal face in a round obtuse angle, anterior face shorter than subpetiolar process, dorsal face slightly concave and continuous to petiolar spine; posterior dorsal portion of petiolar node forming blunt projections giving concave aspect to posterior face; with effaced longitudinal to oblique striae on posterior portion.

Pilosity. Pubescence on mesosoma relatively long, separated each other about its own length. Pronotum with relative long erect hairs.

Natural history: Little is known about this species. It occurs in northwestern South America ( Fig. 67 ) and specimens have been collected from pastures as well as primary forests, from altitudes between 800 and 1,473 m.

Comments: Odontomachus bradleyi can be recognized by its anteriorly angular petiolar node, resembling that of O. chelifer . Both can be quickly distinguished by the following: Odontomachus bradleyi has the pronotum with longitudinal striae on the central portion that becomes concentric laterally, while in O. chelifer the striae are always transverse, forming or not concentric ellipses. The anterior section of the node in O. bradleyi is shorter than in O. chelifer . The gastral terga of O. bradleyi are imbricate while in O. chelifer they are transversely striae.

Material examined: 13☿, 1♀. ECUADOR: Napo: 23 km NE Baeza (1☿) ; Huahua Sumaco (1☿) ; Reventador (1☿) ; Río Hollín (1☿) ; San Rafael (4☿) . Pastaza: [Centro de Investigación] Sumak Kausay [Kawsay] (1☿) . Sucumbíos: El Chaco (1♀) . Zamora Chinchipe: Cantón Yanatzu (1☿) ; Cordillera del Condor (2☿) . VENEZUELA: Aragua: Parque Nacional Henri Pittier Grande (1☿) .

Odontomachus caelatus Brown, 1976 ( Fig. 15-A , 16-A , 34-C , 68 , 60 and 70 and 71 )

Odontomachus caelatus Brown, 1976: 140 (☿ and ♂).

Type specimens: Holotype. BRASIL: [Brazil: Amazonas], Mun [icipality] Manaus, Reserva Ducke, 09.vi.1971, [Brown,] W. L. & Brown, D. E. col., rain for[est]. MZSP77590 1☿ [ MZSUP] . Paratype. Same locality as holotype, MZSP77591 [ MZSUP]/ [Images] v-6 BMNH (E) 1014008, CASENT0900611 1☿ [ BMNH] .

Paratype. B[ RITISH] G[ UIANA][ Guyana]: Gr [eat] Batavia I [sland], Cuyuni River, Aug 4.20 [4.viii.1920], #371, N. M. W[heeler] col., MZSP77592 1☿ [ MZSUP] .

Etymology: From the Latin word caelatus = engrave in relief; probably referring to the unique sculpturing pattern on the mesonotum.

Diagnosis: (☿) Propleuron with fine transverse striae concentric on central portion. Mesonotum with longitudinal striae diverging anteriorly forming concentric arcs laterally. Mesopleuron with fine regular transverse striae on all surface. Gastral terga with regular longitudinal striae diverging posteriorly. (♀) Propleuron and gastral terga as in worker. Meso and metascutellum with regular longitudinal striae. (♂) Body color dark brown. Mesoscutellum in antero-dorsal view with dorsal margin concave. Metascutellum with sharp keel. Posterior face of propodeum with fine, short, transverse and irregular striae punctate.

Worker

Holotype measurements: EL 0.45, HL 3.25, HoW 2.55, HvW 2.11, HW 2.32, ML 1.73, SL 2.87, PnW 1.45, WL 3.83, FL 3.16, PTH 1.4, PTL 0.7, PtW 0.52, GL 2.93, TL 12.44. CI 0.71, MI 0.53, PtI 2, SI 0.88, VI 0.9.

Non-type measurements: EL 0.40-0.50, HL 2.80-3.50, HoW 2.10-2.80, HvW 1.70-2.50, HW 1.90-2.60, ML 1.60-2.10, SL 2.60-3.20, PnW 1.20-1.60, WL 3.20-4.10, FL 2.9-3.5, PTH 0.90-1.60, PTL 0.50-0.70, PTW 0.40-0.60, GL 2.60-4.80, TL 11.10-14.60. CI 0.66-0.75, MI 0.53-0.60, PtI 1.28-2.66, SI 0.85-0.96, VI 0.89-1.00 (n= 30).

Head. Vertex rectangular, wider than long in frontal view; with regular longitudinal striae. Posterior margin concave medially; occipital carina not forming nuchal collar. Cephalic constriction conspicuous. Frontal lobes striate. Ocular bridges posteriorly forming arc. Eye relatively large (EL> 0.4); rounded, posterior margin rounded. Clypeus with fine longitudinal striae on median portion. Malar area with fine longitudinal to oblique striae in latero-oblique view.

Mandible. Almost as long as anterior head portion. External margin slightly convex. Masticatory margin with denticles that serially increase in size apically. Palp formula 4,3.

Antenna. Scape surpassing occipital corner by pedicel length.

Mesosoma. Pronotum in lateral view angulate, dorsal margin slightly convex; neck well developed anteriorly in dorsal view; lateral margin forming obtuse angle posteriorly; central disc of pronotum with longitudinal striae, lateral striae forming concentric arcs directed anteriorly. Propleuron with fine transverse striae concentric on central portion slightly effaced. Mesonotum wider than long, strongly curved anteriorly, slightly concave medially; with regular longitudinal striae diverging anteriorly and posteriorly; striae in lateral view forming concentric arcs anteriorly. Mesopleuron with rounded carina on anteroventral portion; fine regular transverse striae on all surface. Mesometanotal sulcus vestigial, metanotum continuous with mesonotum; with regular longitudinal striae. Metapleural gland bulla with transverse striae finer than metapleuron striae. Propodeum in lateral view irregular with two shallow impressions; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process open, cuticle border forming acute pair of lobes converging medially deeply impressed anteriorly; completely dense punctate, with regular transverse to oblique striae diverging posteriorly.

Petiole. Sessile. Node conical, anterior margin slightly convex continuous to petiolar spine; posterior face convex on dorsal portion and concave medially forming two blunt lateral projections. Spine robust, long, straight to slightly curved posteriorly. Regular transverse striae on all surface except by dorsal portion of posterior face. Subpetiolar process wider than long; tip slightly rounded; posterior face concave; posterior portion slightly concave.

Gaster. First tergum almost higher than long; anterior and dorsal margin meeting in an obtuse angle; dorsal face convex. First tergum dorsal face with regular longitudinal striae diverging posteriorly. Second tergum dorsal face with regular longitudinal striae. Third tergum with regular oblique striae converging posteriorly. Fourth tergum with fine regular transverse striae slightly curved posteriorly.

Color and size. Body reddish brown. Legs and antennae light brown. Relatively medium size ants.

Pilosity. Inconspicuous and short pubescence spread all over the body. Pubescence on petiole limited to anterior face extending to lateral faces. Short hairs on anterior face of pro-coxa smaller than coxal width. Pronotum with three or four pairs of long, curved erect hairs longer than maximum procoxa width. Long erect hairs on posterior 3/4 of gastral terga directed posteriorly, as long as pronotum hairs.

Gyne

Non-type measurements: EL 0.50-0.60, HL 3.30-3.50, HoW 2.70-2.8, HvW 2.40-2.5, HW 2.50-2.60, ML 1.80-2.00, SL 3.10, PnW 1.70-1.80, WL 4.30-4.50, FL 3.30-3.40, FL 3.30-3.40, FWL 8.20-8.30, PTH 1.50-1.70, PTL 0.70- 0.90, PTW 0.60-0.70, GL 4.00-4.90, TL 14.80-15.30. CI 0.71-0.76, MI 0.54-0.57, PtI 1.87-2.28, SI 0.88-0.93, VI 0.96-1.0, (n= 4).

Mesosoma. Pronotum slightly longer than high in lateral view, dorsal margin concave almost forming obtuse angle; lateral margins converging anteriorly forming a neck in dorsal view; pronotal dorsum with regular transverse striae, curved anteriorly; striae in lateral view on anterior portion forming concentric arcs directed posteriorly, on ventral portion longitudinal and curved dorsally, on dorsal posterior portion transverse. Subalar area conspicuous with pronotum; with regular striae. Mesoscutum anterior and dorsal margin forming single convexity in lateral view; with regular longitudinal striae in dorsal view; striae between parapsidial line and parascutal area oblique, directed medially. Parapsidial line curved on posterior portion, well-marked, diverging anteriorly. Parascutal area smooth and shining. Notopropodeal sulcus scrobiculate. Axilla and mesoscutellum as striated as mesoscutum. Mesoscutellum slightly concave medially. Metascutellum with irregular transverse striae and with longitudinal carina.

Wing. Color pale brown translucid. Forewing ML1 curved. RsL1 straight; as long as Rs+M. RSL2-3 slightly sinuous. Rs+M and ML2 forming single line, slightly curved, almost forming angle with RsL2-3. Hindwing 1rs-m vein curved. 9 to 10 hamuli.

Petiole. As in worker with petiolar spine and sculpturing coarser.

Pilosity. Pubescence on mesosoma inconspicuous, almost completely absent. Pronotum with one or two pairs of short hairs, shorter than pronotum half-height. Mesoscutellum with pair of long hair curved medially to posteriorly.

Male

Non-type measurements: EL 0.71-0.74, HL 1.1, OW 0.15, OES 0.37-0.40, IOW 0.21-0.24, WL 3.2-3.6, FWL 6.1- 6.5, PTH 1.0-1.1, PTL 0.6, PtW 0.5, GL 2.7-3.0, TL 7.0-7.6. PtI 1.66-1.83 (n= 5).

Head. Palp formula 4,3. lateral ocelli not surpassing posterior margin; posterior margin between lateral ocelli straight to slightly convex.

Mesosoma. Pronotal dorsum with transverse fine irregular striae limited to lateral posterior portion; with oblique irregular striae on anteroventral portion, surface between them punctate. Propleuron with fine irregular and oblique striae densely punctate. Mesoscutum anteriorly with punctures separated each other by about their length gradually becoming juxtaposed posteriorly dorsal surface with longitudinal median carina, inconspicuous longitudinal regular to irregular striae densely punctate next to it and parapsidial lines. Axilla with sparse and fine longitudinal striae, micro sculpture present between them. Mesoscutellum medially concave; with regular sparse longitudinal striae anteriorly, gradually effacing posteriorly with sparse punctures separated each other by about their length with median carina on posterior portion. Metascutellum with transverse irregular striae densely punctate, with longitudinal keel. Anepisternum with inconspicuous fine irregular striae on ventral portion gradually becoming smooth and shining. Katepisternum with dense micro sculpture in ventral portion becoming smooth and shining dorsally. Metapleuron with irregular longitudinal to oblique striae, surface between them densely punctate. Metepisternum with longitudinal to oblique irregular striae, surface between them densely punctate. Metapleuron and propodeum separated by shallow and relatively wide sulcus slightly scrobiculate. Propodeal dorsum with longitudinal fine irregular striae diverging posteriorly, with dense micro sculpture of reticulate aspect between them, surface between them densely punctate; dorsal and posterior face of propodeum separated or not by coarse irregular striae; posterior face with fine irregular striae varying in disposition.

Wing. Light brown translucid. Hamuli varying between 8 and 9. Pterostigma brown, darker than wing surface.

Petiole. Sessile; dorsal portion acute, slightly concave laterally; with fine short irregular and transverse striae densely punctate. Subpetiolar process with apical portion sub-quadrate. Sternum posteriorly concave forming blunt lobe posterior to subpetiolar process.

Color and size. Entire body brown. Gaster, legs and antennae lighter. Relatively large to medium size.

Pilosity. Head, mesosoma and gaster with dense appressed pubescence. Pronotum with two thin erect hairs on posterior portion. Mesoscuttum with group of erect curved hairs on central portion longer than pronotum hairs. Pubescence on posterior face of petiole absent. Thin, erect short hairs on posterior portion and gaster segments I and II, hairs on segments III, IV and V almost larger.

Natural history: What is known about its natural history is limited to information in the description and labels from examined material: some nests were collected under rotten wood and in the soil under leaves on a tree trunk base. It has been collected from leaf litter and with baits of sardine and guava paste. It inhabits the epigeic strata of forests, from 170 to 650 m, and is widely distributed in the Amazon ( Fig. 71 ).

Comments: Among the species with longitudinal striae on the mesonotum, O. caelatus can be quickly recognized by the concentric arcs, visible in oblique or lateral views. Also, the regular longitudinal gastral striae that usually diverge posteriorly are unique. Odontomachus scalptus is often confused with O. caelatus , but its mesonotal striae do not form concentric arcs and the gastral terga are anteriorly punctate, then gradually becoming striate or completely densely punctate. Gynes of O. caelatus have the gastral terga striate, the scutellum with robust longitudinal striae, inconspicuous pubescence, and the reddish dark-brown tegument has a silky shine. Some specimens have the striae on the first gaster terga diverging laterally. The petiolar spine can be variable in size and shape. Larger specimens usually have the anteroventral projections of the mesopleuron more protruding. The body color can be lighter in some populations, but still reddish brown. These variations are not stable and are widespread across its whole geographical distribution.

The main variation in males is the striation on the metapleuron and propodeum. Some males have sparse concentric striae on the metapleuron, differing from the usual longitudinal or oblique striae. The dorsal propodeal striation varies from coarse to fine with longitudinal striae diverging posteriorly. According to Brown (1976), the male of O. caelatus can be distinguished from O. haematodus and O. bauri by its larger size and body color entirely black. However, comparing it with other males, O. caelatus is most similar to O. biumbonatus and O. xeta sp. nov. All of these three have the apex of the petiolar node with two blunt projections on their posterior face. They also share the concave mesoscutellum and the petiolar sternum with a blunt posterior projection. Odontomachus caelatus males are easily distinguished by the coarsely striated metascutellum and the transverse rugulose-punctate sculpturing on the posterior propodeal face. Both characters are absent in O. biumbonatus and O. xeta sp. nov.

The southernmost record was collected in the 1970s in Vera, Mato Grosso state ( Fig. 71 ). Since then, no more specimens from this site and its immediate surroundings have been found in collections. Probably, habitat loss due to agricultural activity explain the absence of more records considering that O. caelatus inhabits forest areas.

Material examined: 73☿, 1♀, 34♂. BRAZIL: Acre: Cruzeiro do Sul (1☿) ; Senador Guiomard (1☿) . Amapá: Serra do Navio (3☿) . Amazonas: Manaus (30☿, 30♂) ; Pres [idente] Figueiredo (1☿) ; R[o]d[ovia] 24 km NE of Manaus (1☿) ; São Gabriel da Cachoeira (1♂) ; [ Without a specific locality] (1☿) . Mato Grosso: Vila Vera [Vera] (1♀) . Pará: Belém (4☿) ; Belterra (2☿) ; Jari (8☿) ; Óbidos (1☿) ; Paragominas (1☿) ; Parauapebas (1☿) ; S Norte Carajás (3☿) ; Tucuruí (2♂) . Rondônia: Nova Marmoré (1♂) ; Porto Velho (5☿) . [Roraima]: 66 km N Manaus on Caracacaraí R[oa]d (2☿) . ECUADOR: Napo: Limoncocha (1☿) . GUYANA: [Cuyúni–Mazarúni]: Great Batavia [Island] (1☿) . VENEZUELA: [Amazonas], Mavaca (2☿) . [no further data] Maracá, Haut Orenoque (4☿) .

Odontomachus chelifer ( Latreille, 1802) ( Figures 18-A , 19-A , 30-A , 38-B , 39-A , 67 , 72 , 73 and 74 )

Formica chelifera Latreille, 1802: 188 (☿); combination in Odontomachus by Latreille, 1807: 128; Forel, 1909: 252 (♀ and ♂); Wheeler & Wheeler, 1952: 651 (larvae).

Odontomachus chelifer var. leptocephalus Emery, 1890: 45 (☿ in text); subspecies of Odontomachus chelifer by Dalla Torre, 1893: 49; junior synonym of Odontomachus chelifer by Emery, 1911: 114.0

Odontomachus haematodus r. theresiae Forel, 1895b: 41 (☿); junior synonym of Odontomachus chelifer by Forel, 1899: 19; Emery, 1901: 53 (♂); junior synonym of Odontomachus chelifer by Emery, 1901: 53.

Odontomachus chelifer var. emacerata ( Santschi, 1922) : 243 (☿); subspecies of Odontomachus chelifer by Kempf, 1972: 170; junior synonym of Odontomachus chelifer by Brown, 1976: 103.

Type specimens: Syntype [Images]. Odontomachus chelifer var. emacerata Santschi, 1912 ; RÉPLUBL. ARGENTINE [ ARGENTINA]: Chaco Dp [Department] Santiago del Estero, Rio Dulce , Collection Wagner [col.], Sammlung, Dr. F. Santschi Kairouan. ANTWEB CASENT0915242 1☿ [ NHMB] .

Holotype [Images]. Odontomachus chelifer var. leptocephalus Emery, 1890 ; [ BRAZIL]: Rio Grande [do Sul], Ihering [col], ANTWEB CASENT0904002 1☿ [ MSNG].

Syntype [Images]. Odontomachus haematodus r. theresiae Forel, 1895b ; [ MÉXICO: Colorado next to Veracruz] (unreadable) COSTE RICHE [ Costa Rica ], [ Princess Teresa da Baviera col.] Coll. Forel, ANTWEB CASENT0907426 1☿ [ MHNG] .

Etymology: Combination of the Greek words chele = claw + phero bear, carry; probably referring to the shape of the mandible apex.

Diagnosis: (☿) Appendages yellowish or light brown always lighter than the body color. Rectangular vertex almost long than wide striated longitudinally. Central disc of pronotum with transverse striae. Metasternum process forming a pair of cuticle borders slight forming bilobate projections medially and deeply separated by longitudinal sulcus on metasternum surface. Petiole sessile, angulate node. Dorsum of first gaster tergum with fine transverse striae. (♀) Vertex, petiole and gaster as in worker. (♂) Body dark brown and head lighter. Mesoscutum and mesoscutellum in dorsal view with conspicuous striae. Posterior face of propodeum with concentric striae forming circles or arcs.

Worker

Non-type measurements: EL 0.30-0.60, HL 2.40-4.30, HoW 1.60-3.00, HvW 1.20-2.50, HW 1.40-2.60, ML 1.50- 2.60, SL 2.40-4.10, PnW 0.90-1.70, WL 3.10-5.50, FL 2.80-4.80, PTH 1.00-1.90, PTL 0.60-1.00, PTW 0.30-0.60, GL 2.50-5.20 TL 10.1-18.00. CI 0.44-0.63, MI 0.48-0.70, PtI 1.30-2.12, SI 0.76-1.06, VI 0.85-0.96 (n= 34).

Head: Vertex rectangular to trapezoidal, length larger than its half-width in frontal view; with regular longitudinal striae diverging posteriorly. Posterior margin concave medially; occipital carina not forming nuchal collar. Cephalic constriction conspicuous. Frontal lobes striated. Ocular bridges posteriorly forming arc. Eye relatively large (EL> 0.4); rounded, posterior margin rounded. Clypeus with inconspicuous micro-sculpturing on median portion. Malar area with fine regular transverse to oblique striae on anterior portion in latero-oblique view, posterior portion smooth and shining.

Mandible: Almost as long as anterior head portion. External margin straight to slightly convex. Masticatory margin with denticles that serially increase in size apically. Palp formula 4,3.

Antenna: Scape surpassing occipital corner by more than pedicel length.

Mesosoma: Pronotum in lateral view triangular, dorsal margin convex; neck well developed anteriorly in dorsal view; lateral margin rounded with obtuse angle posteriorly; central disc of pronotum with regular transverse striae, lateral striae might form concentric ellipses curved anteriorly. Propleuron smooth and shining, regular fine oblique striae restricted to anterior portion gradually fading posteriorly. Mesonotum with regular transverse striae slightly curved anteriorly. Mesopleuron with rounded carina on anteroventral portion; mostly smooth and shining, anterior portion with regular transverse striae curved dorsal-anteriorly. Mesometanotal sulcus well-marked, smooth and shining to shallow scrobiculate. Metanotum with regular transverse striae curved anteriorly; posteriorly constricted on laterals around metanotal spiracles. Metapleural gland bulla with irregular transverse striae finer than metapleuron striae. Propodeum in lateral view slightly concave on middle length; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process open, cuticle border slight forming bilobate projections medially or lateral projections; regular transverse striae anteriorly; posterior portion varying in sculpture.

Petiole: Sessile. Angulate node, anterior margin in lateral view meeting dorsal margin in an obtuse angle, anterior margin varying in length. Spine acute, straight or slightly curved posteriorly, robust and flattened laterally, strongly curved posteriorly. Oblique striae on lateral face extending to posterior margin limited to ventral portion. Subpetiolar process longer than wider; tip rectangular to blunt; posterior portion not concave.

Gaster: First tergum usually longer than higher; anterior and dorsal margin meeting in a slightly convex surface not forming an angle. First and second terga in dorsal view with regular transverse striae slightly curved anteriorly. Third and fourth terga slightly striate anteriorly, striae gradually fading posteriorly.

Color and size: Body dark brown to nut-brown, head usually slightly darker. Legs and antennae lighter brown to yellowish. Medium to large size ants.

Pilosity: Scattered inconspicuous pubescence spread over the body. Gaster with dense pubescence separated each other by less than its length. Short hairs on anterior portion of procoxa smaller than coxae width; short hairs on ventral portion of gaster. Long erect hairs on posterior 2/3 of gastral terga directed posteriorly.

Gyne

Non-type measurements: EL 0.50-0.70, HL 3.60-4.00, HoW 2.50-2.90, HvW 2.00-2.30, HW 2.10-2.50, ML 2.00- 2.40, SL 3.40-3.90, PnW 1.60-1.80, WL 4.90-5.80, FL 3.90-4.60, FWL 9.00-9.70, PTH 1.50-2.00, PTL 0.80-1.00, PTW 0.60-0.70, GL 4.10-5.90, TL 15.90-19.10. CI 0.57-0.62, MI 0.52-0.63, PtI 1.8-2.11, SI 0.89-1.0, VI 0.91-0.95 (n= 9).

Mesosoma. Pronotum almost longer than high in lateral view, dorsal margin straight; lateral margins converging anteriorly forming a neck in dorsal view; pronotal dorsum with regular transverse striae curved on transition between dorsal and lateral face, effaced on latero-ventral portion. Subalar area separated from pronotum by sulcus at least on dorsal portion; striae slightly finer than pronotum. Mesoscutum anterior and dorsal margins meeting in convex surface, form an almost rounded right angle; with slightly wider than long in dorsal view; with regular longitudinal striae converging posteriorly; striae between parapsidial line and parascutal area oblique, directed medially. Parapsidial line curved, well-marked. Parascutal area scrobiculate. Notopropodeal sulcus scrobiculate. Axilla with regular longitudinal striae. Mesoscutellum with regular longitudinal striae with longitudinal carina. Metascutellum with microsculpturing on anterior portion reaching or not posterior portion.

Wing. Color dull brown, darker on areas closer to veins. Forewing ML1 curved. RsL1 straight; almost as long as Rs+M. RSL2-3 slightly curved. ML2 short, about half-length of Rs+M. Rs+M and ML2 forming single slightly curved line, not forming angle with RsL2-3. Vein cu-a almost reaching M+Cu ML1 angle. Hindwing 1rs-m vein straight. 10 to 13 hamuli.

Petiole. Angulated node, anterior face straight, dorsal face slightly concave.

Pilosity. Pubescence on pronotum and propodeum short, dense, separated each other about its own length. Pubescence on mesoscutum, mesoscutellum and metascutellum long, about double length of pronotum pubescence, separated each other about its length.

Male

Non-type measurements: EL 0.70-0.90, HL 1.10-1.30, OW 0.10-1.30, OES 0.20-0.30, IOW 0.27, WL 3.60-4.20, FWL 6.60-8.70, PTH 1.00-1.20, PTL 0.80-1.00, PTW 0.50-0.60, GL 3.50-4.40, TL 9.00-10.70. PtI 1.10-1.50 (n= 9).

Head. Palp formula 5,3. Lateral ocelli surpassing posterior margin in frontal view; posterior margin between lateral ocelli concave, reaching median ocellus.

Mesosoma. Pronotal dorsum with fine irregular transverse striae with micro sculpture of reticulate aspect between them; with fine irregular longitudinal striae becoming effaced on ventral portion in lateral view. Propleuron micro sculptured. Mesoscutum anteriorly with fine regular transverse striae on anterior portion with longitudinal sulcus standing out from striae, dorsal surface with regular longitudinal striae, striae on median portion converging posteriorly. Axilla and mesoscutellum with longitudinal striae. Mesoscutellum convex. Metascutellum with transverse striae and longitudinal carina. Anepisternum with inconspicuous micro sculpture on dorsal portion, ventral portion with fine longitudinal striae. Katepisternum with fine longitudinal striae. Metapleuron with irregular longitudinal striae, coarser than katepisternum striae. Metepisternum with longitudinal irregular striae curved ventrally. Metapleuron and propodeum separated by longitudinal carina extending from metepisternum to propodeal spiracle, and by discontinuous and fine longitudinal striae posteriorly to it. Propodeal dorsum with oblique striae diverging posteriorly to propodeal spiracle; dorsal and posterior face of propodeum delimitated by striae on dorsal face; posterior face with concentric striae forming arcs directed posteriorly, circles or ellipses.

Wing. Light brown. Hamuli varying from 10 to 13. Pterostigma brown, darker than wing surface.

Petiole. Sessile; anterior margin convex, apical portion acute to blunt in lateral view; with micro regular and oblique striae on lateral portion extending to ventral portion of posterior face. Subpetiolar process with apical portion subquadrate to blunt anteriorly. Sternum not concave posteriorly.

Color and size. Head, prothorax, mesothorax, petiole and gaster testaceous. Mesosoma yellowish brown with irregular areas lighter. Relatively large size.

Pilosity. Head, mesosoma, petiole and gaster with dense appressed pubescence. Pronotum with two pairs of thin erect hairs on posterior portion, one pair almost two times larger than the other. Thin and erect short hairs on posterior portion of gaster segments I and II, hairs on segments III, IV and V almost two times longer.

Natural history: Guimarães et al. (2018) studied several nests of O. chelifer in the ground associated with the root systems of large trees. The nests have multiple entrances covered by leaf litter with more than one vertical tunnel connected to several horizontal chambers that are oval or elliptical, covered with decomposing vegetal matter. The number of chambers varies, they can reach from 34–77 cm with depths reaching 1.34 m. Colonies are large, including 304– 864 workers. Termites were found in the nests. Also, a species of Camponotus Mayr, 1861 and Pheidole Westwood, 1839 were found using the nest entrances of O. chelifer that allowed them access to their nests.

Fowler (1980) observed a colony of O. chelifer foraging on an abandoned Atta sexdens ( Linnaeus, 1758) soil mound and in the nest galleries. In the field, the workers aggregated close to their own nest entrance and attacked A. sexdens that eventually foraged next to it. In laboratory experiments, Fowler (1980) offered A. sexdens workers to O. chelifer as a food resource but they were rejected, the same author suggests that monogynous colonies can have 86– 136 workers and 22– 46 pupae.

In polygynous colonies, there is hierarchical dominance between the queens ( Heinze et al. 1994; Medeiros et al. 1992). When agonistic interactions happen, the dominant queen touches the submissive queen’s head and then raises the submissive queen. When raised, the submissive queen retracts the appendages and assumes the pupal position. Queens with higher status lay more eggs and have more developed ovaries than submissive ones, which forage less and often attack new-winged queens ( Heinze et al. 1994).

This species occasionally forages in low vegetation, and preys on termites and dead invertebrates ( Raimundo et al. 2009). Raimundo et al. (2009) observed that during the sunset, a group of workers stayed near at the nest entrance and started to individually forage at night The foraging activity was higher during the hot rainy season from November to March. Raimundo et al (2009) also observed that the most frequent prey of O. chelifer in Campinas, São Paulo, Brazil, was Neocapritermes (Holmgren, 1912) ( Blattodea : Isoptera). The authors also observed workers of A. sexdens , an Acromyrmex sp. , and Camponotus spp. being preyed. Occasionally, some foragers would bring fragments of mammal feces to the nest. Often, their prey would be stolen by a forager of Pachycondyla striata Smith, 1858 ( Raimundo et al. 2009).

In Cerrado, O. chelifer is a secondary seed disperser, removing the aril from seeds and transporting it to the nest ( Magalhães et al. 2018), and plays the same role in areas of Restinga habitats ( Passos & Oliveira, 2003). According to Almeida et al. (2019), this role as secondary dispersers possibly compensates for the absence of small mammals and birds as seed dispersers in small fragments of the Atlantic Rainforest, hence contributing to landscape maintenance.

The pupae of O. chelifer has been reported to be parasitized by Kapala pr. sulcifacis ( Hymenoptera : Eucharitidae ) ( De la Mora et al. 2015). The snapping mandibles of O. chelifer have been reported to reach velocities of 35.9± 7.7 m /s– 1 ( Spagna et al. 2008). The karyotype of O. chelifer is 2n= 44, 2K= 4SM + 40T ( Santos et al. 2010). In a study on mandible gland extracts of O. chelifer by Xu et al. (2018), the authors identified the presence of six pyrazines.

Odontomachus chelifer can be collected using pitfall traps, Winkler’s extractor, and bait stations. Males and gynes can be collected at light- and Malaise-traps.It is found in primary forested areas to anthropized areas, such as city parks or urban gardens, occurring from sea level to 1,900 m. The distribution of O. chelifer ranges from the northeast of Argentina to Mexico, and it is abundant and frequent in the Cerrado and Atlantic Forest biomes ( Fig. 67 ), which probably explains its wide distribution and frequency in disturbed or urban areas. Besides the type-locality of O. chelifer thereseae in Mexico, the other northernmost record is from Costa Rica. As in South America, O. chelifer seems to be less abundant and frequent in dry areas in Central America.

Comments: Odontomachus chelifer is the only species in the Neotropical region with transverse striae on the gastral terga, a quickly assessed trait. The only other species with an anteriorly angular petiolar node is O. bradleyi , but it has longitudinal striae on the central disk of the pronotum, and its node is relatively narrow compared to O. chelifer . To the naked eye, lighter specimens of O. chelifer can be confused with O. affinis due to their median to large size. Odontomachus chelifer has the vertex striate, the first and second gastral terga with transverse striae; whereas O. affinis has both the vertex and gastral terga smooth and shining.

Odontomachus chelifer workers show a wide variation of size, color, striation of some sclerites, petiolar node proportions, and metasternal processes. The pronotum striae can be entirely transverse or form concentric transverse ellipses on the anterior portion. The striae on the gastral terga vary from coarse transverse to fine and weak. Both variations are not fixed within the populations, not even in the same series. The Petiolar node spine also varies in size and thickness.

There are three forms of O. chelifer :

1) The most common form has short transverse striae on the anterolateral portion of the propleuron, and the rest of the surface is finely obliquely striate or imbricate; the metasternal process is open, with the lateral carina forming a pair of lobes separated by a deep concavity; the petiolar node has the anterior portion relatively short. This form is widely distributed in South America, especially from the mid-west, the northeast, and south of Brazil.

2) The second form has a light brown, sometimes ferruginous, body, and the propleuron is similar to the common form, but with the central portion smooth and shining; the ventral posterior portion on the lateral face of pronotum has effaced striae or it is smooth and shining; the metasternal process is also open and bilobate, but the lobes are not separated by a deep concavity, instead, its surface is on the same level of the lobes; the petiolar node has the dorsal face slightly concave and the spine with a small blunt projection on its base. Few specimens were observed with this morphology and they occur in the Cerrado region of Goiás, Minas Gerais, and Mato Grosso states in Brazil. The first form and this one are sympatric, with some intermediate forms between both also present, especially in São Paulo and Paraná states.

3) The third form is usually darker and large; the propleuron is completely covered with fine irregular and oblique striae or is coarsely imbricate; the metasternal process is also bilobate and similar to that in O. dubius sp. nov., but it does not expand laterally to form a pair of lamellated lobes, instead the middle portion of their borders are thicker and form lobes separated from each other like those in O. erythrocephalus or O. scalptus ; the petiolar node usually has the anterior portion higher and the striae go towards the posterior portion becoming oblique. This variation is more frequent in Amazonian and Central America, with intermediary forms between it and the first form present in Venezuela and Colombia. Some relatively large specimens in the south of Brazil also have the posterior face of petiole with conspicuous striae, but they are not dark brown and the metasternum is as in the common form.

In these three cases, it is difficult to recognize some as being a distinct species because the gradient of intermediate forms occurs in sympatry. The third form is arguably the most unique, especially regarding the metasternal process and the petiolar striae. The distribution, restricted to rainforests of northern South America and Central America, maybe is another indication of a possible distinct species.

In the case of males, the greatest variation is observed in the propodeal sculpturing. The striae usually form concentric circles, but they also can form ellipses or even dorsally directed arcs. The body color can be entirely brown to dark brown or bicolored with the head and gaster lighter than the mesosoma and the petiole. One aberrant specimen from Chapada dos Guimarães in Mato Grosso was observed with well-developed lateral ocelli; mesoscutellum with median longitudinal carina; metascutellum with well-developed longitudinal carina forming a keel; propodeum with striae forming longitudinal concentric ellipses with median longitudinal striae; and body entirely yellowish. This specimen does not match with any other Odontomachus species, though it slightly resembles O. chelifer . This could be an aberrant form, but it could also be a possible new species. Unfortunately, male specimens from Amazonian regions and Central America were not observed. Male morphology is essential to understanding the boundaries of these three variations observed in O. chelifer .

Material examined: 474☿, 12♀, 19♂. ARGENTINA : Tucumán: La Soledad-Cañete (2☿) . BOLIVIA: [Santa Cruz] : Santa Cruz de la Sierra (1☿) . BRAZIL: Acre: Rio Branco (1☿) . Amazonas: Manaus (2☿) . Bahia: Andaraí (2☿) ; Camacã (1☿) ; Itambé (1☿) ; Itororó (2☿) ; Maracás (3☿) ; Milagres (1☿) . Ceará: Maranguape (2☿) ; [no further data] (1♂) . Distrito Federal: Águas Emendadas (1☿) ; APA Gama-Cabeça de Veado (1☿) ; Brasília (5☿, 1♀) . Espírito Santo: Cariacica (4☿) ; Santa Teresa (1☿) . Goiás: Aporé (4☿) ; Cavalcante (4☿) ; Jataí (46☿, 1♀) ; Mineiros (2☿) ; Serranópolis (4☿) . Maranhão: Anapurus (1☿) . Mato Grosso: Chapada dos Guimarães (5☿) ; Poxoréu (8☿) . Mato Grosso do Sul: Dourados (1☿) . Minas Gerais: Belo Horizonte (2☿) ; Boa Esperança (8☿) ; Chapada Gaúcha (1☿) ; Divinópolis (1☿) ; Itumirim (1☿) ; Itutinga (1☿) ; Machado (1☿) ; Mariana (1☿, 1♀) ; Monte Camelo (1☿) ; Nova Lima (4☿) ; Pandeiros (1☿) ; Poço fundo (3☿) ; Rio Pardo de Minas (1☿) ; Parque Estadual Serra do Ouro Branco (1☿) ; Represa do Estreito (1☿) ; Rio Parnaíba (2☿) ; Rodovia MG 355 (1☿) ; Santana do Riacho (1☿) ; São Tiago (2☿) ; Serra da Canastra (2☿) Viçosa (4☿, 1♀) . Pará: Jari (1☿) ; Parauapebas (3☿) . Pernambuco: Caruaru (5♂) . Paraná: Antonina (28☿, 7♂) ; Campina Grande do Sul (1☿) ; Colombo (3☿) ; Cornélio Procópio (1☿) ; Curitiba (20☿, 1♀) ; Diamante do Norte (1☿) ; Floresta Estadual do Palmito 28km (1☿) ; Guaraqueçaba (2☿) ; Ilha do Mel (6☿) ; Marumbi (2☿) ; Morretes (1☿, 3♂) ; Palotina (7☿) ; Ponta Grossa (62☿, 2♀) ; Quatro Barras (1☿) ; Santa Terezinha de Itaipu (1☿) ; São José dos Pinhais (1☿, 1♂) ; São Miguel do Iguaçu (2☿) ; Tibagi (4☿, 1♂) . Rio de Janeiro: Angra dos Reis (1☿) ; Itatiaia (6☿) ; Rio de Janeiro (2☿, 1♂) . Roraima: Caracaraí (1☿) ; Paracaima (5☿) . Rio Grande do Sul: Montenegro (8☿) ; Pareci Novo (1☿) ; Porto Alegre (1☿) ; Santa Cruz do Sul (2☿) ; Viamão (1☿, 1♀) . Santa Catarina: Araranguá (2☿) ; Balneário Gaivota (1☿) ; Blumenau (1☿) ; BR 470 Navegantes, Indaial (6☿); Chapecó (1♀) ; Florianópolis (3☿) ; Nova Teutônia (1☿) ; Siderópolis (31☿) . Sergipe: São Cristóvão (1☿) . São Paulo: Águas de Santa Bárbara (1☿) ; Botucatu (3☿, 1♀) ; Campinas (2☿) ; Cardoso (5☿) ; Guarulhos (1☿) ; Ilhabela (1☿) ; Itirapina (4☿, 1♀) ; Macalbal (8☿) ; Mirassol (4☿) ; Mogi das Cruzes (12☿) ; Santos (1☿) ; São Paulo (1☿) ; Mogi Guaçu (3☿) ; Morro Aprazível (2☿) ; Parque Estadual Intervales (3☿) ; Picinguaba (2☿) ; Ribeirão Preto (2☿) ; Rio Claro (2☿) ; São Paulo (1☿) ; São Sebastião (2☿) ; São Vicente (1☿) ; Teodoro Sampaio (2☿) ; Ubatuba (4☿) . COLOMBIA: Casalma. Ap. Monte (1☿) . Cauca: Popayan (6☿) . Cundinamarca: Sasaima (4☿) . Risalda: Pereira (1♀) . [ Without location] (1☿) . COSTA RICA: Cartago: Turrialba (1☿) . ECUADOR: Esmeraldas: Atacames (1☿) . PANAMA: Panamá Oeste: Barro Colorado Island (1☿) . PARAGUAY: Central: San Lorenzo (6☿) . Caaguazú: Pastoreo (3☿) . PERU: Huánuco: Huánuco (2☿) . TRINIDAD AND TOBAGO: San Juan: El Tucuche (1☿) . [no further data] B.W.I. (2☿); Top of Marine Blue (1☿) . VENEZUELA: Amazonas: Alto Orinoco (1☿) ; Bolívar: Auyantepui (1☿) ; Cerro Los Pijiguaos (1☿) ; Parque Nacional Canaima (1☿) . Caracas: Parque Nacional El Ávila (1☿) ; Carabobo: 4.8km SSE Canoabo (1☿) . Miranda: Parque Nacional Guatopo (2☿) . Nueva Esparta: Cerro El Copey (1☿) .

Odontomachus chicomendesi França, Fernandes & Lattke new species urn:lsid:zoobank.org:act:222DAF6C-AEDE-41CE-9CE6-AE2B1C8FA0A0 ( Figures 25-A , 30-C , 37-A , 45-A , 76 , 77 , and 78)

Type specimens: Holotype. BRAZIL: Acre, Mâncio Lima, Parque Nacional Serra do Divisor, Feitosa., R. M., Silva, T. S. & Ferreira, A. C. cols., 15-18.xi.2016, Winkler , 360m, 7°26’56.65” S 73°40’13.94” W [-7.449069, - 73.670539], DZUP591302 1☿ [ DZUP].

Paratypes. Same series of holotype. DZUP 549013 1☿ [ DZUP] and HYM-INPA034966 1☿ [ INPA]. BRAZIL: Acre, Rio Branco, Fazenda Experimental Catuaba , UFAC, J. Lattke col., 07.xi.2006, # 3742, 210m, -10.0778 - 67.6264, DZUP 591303 1☿, DZUP 549015 1☿ and DZUP 549197 1♂ [ DZUP]. BRAZIL: Amazonas, Benjamin Constant , 18-28.IX.1968, K. Lenko col., [Coll. Lenko] 2921, MZSP 77773 4☿, MZSP 77774 4☿, MZSP 77775 3☿ [ MZSUP] .

Etymology: The specific epithet honors the environmental activist Chico Mendes (1944-1988). Chico Mendes was born in the state of Acre, Brazil. He was raised and lived in the Amazonian Forest as a rubber tapper. He fought for the protection of the Amazonian Forest and the rights of rubber tree workers. Unfortunately, he was murdered in his backyard in an ambush at the behest of a squatter (Memorial Chico Mendes, 2022). Since then, he became a symbol for protection of the Amazon and of the traditional people who subsist from it. Additionally, the mesopleural shape of this species resembles the rubber tree knife used in the rubber extraction process.

Diagnosis: (☿) Scape reaching occipital corner but not surpassing it. Mesopleuron with anteroventral portion forming acute projection directed ventrally. Petiolar node conical with spine long and curved posteriorly. (♀) Scape, mesopleuron and petiole as in worker. (♂) Body color black, tarsi whitish. Mesoscutum smooth and shining. Propodeum with coarse rugae.

Worker

Holotype measurements: EL 0.3, HL 2.2, HoW 1.6, HvW 1.4, HW 1.6, ML 1.2, SL 1.9, PnW 1.0, WL 2.5, FL 2.0, PTH 0.5, PtW 0.3, GL 2.2, TL 8.6. CI 0.72, MI 0.54, PtI 2.0, SI 0.86, VI 0.87.

Non-type measurements: EL 0.3-0.4, HL 1.8-2.5, HoW 1.4-1.9, HvW 1.2-1.9, HW 1.3-2.1, ML 1.0-1.3, SL 1.7-2.1, PnW 0.8-1.1, WL 2.2-2.9, FL 1.9-2.4, PTH 0.8-1.1, PTL 0.4-0.6, PTW 0.3-0.5, GL 1.7-3.2 TL 7.1-10.0. CI 0.69-0.95, MI 0.50-0.60, PtI 1.83-2.75, SI 0.81-0.95, VI 0.80-0.94 (n= 40).

Head. Vertex trapezoidal, wider than long in frontal view; with regular longitudinal striae diverging posteriorly. Posterior margin concave medially; occipital carina not forming nuchal collar. Cephalic constriction conspicuous. Frontal lobes striated. Ocular bridges posteriorly forming arc. Eye relatively large (EL> 0.4); rounded, posterior margin rounded. Clypeus with fine regular longitudinal striae on median portion. Malar area wrinkly on anterior portion in latero-oblique view, posterior portion smooth and shining.

Mandible. Almost as long as anterior head portion. External margin slightly convex. Masticatory margin with denticles that serially increase in size apically. Palp formula 4,3.

Antenna. Scape reaching occipital corner but not surpassing it.

Mesosoma. Pronotum in lateral view rounded, dorsal margin convex; neck well developed anteriorly in dorsal view; lateral margin rounded; central disc of pronotum with regular longitudinal striae, external striae forming concentric circles. Propleuron smooth and shining. Mesonotum slightly larger than wide, narrow posteriorly; with regular transverse striae. Mesopleuron with anteroventral portion forming acute projection directed ventrally; mostly smooth and shining, anterior portion with regular transverse striae curved dorsal-anteriorly. Mesometanotal sulcus well-marked, scrobiculate; curved anteriorly. Metanotum vestigial as long as notopropodeal sulcus; with fine irregular transverse striae. Metapleural gland bulla with transverse striae. Propodeum in lateral view almost straight, with two shallow impressions; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process close, forming fine arc with notch medially or not; regular fine transverse striae.

Petiole. Sessile. Conical node, anterior margin in lateral view straight to slightly convex, continuous with petiolar spine. Spine acute, straight or curved posteriorly, usually as long as node half-height. Fine irregular transverse striae on anterior margin and lateral face becoming imbricate to inconspicuous dorsally. Subpetiolar process wider than long keel-shaped; tip acute; posterior portion concave.

Gaster. First tergum almost higher than long; anterior and dorsal margin meeting in an obtuse angle; dorsal margin convex. dorsal face of all terga imbricate or almost smooth and shining.

Color and size. Body color varying from dark brown almost black to light brown. Legs and antennae lighter. Medium ants.

Pilosity. Dense, conspicuous and short pubescence spread over the body, separated each other about their length. Short hairs on anterior portion of procoxa, pronotum and gaster, smaller than coxae width. Short hairs on posterior 3/4 of gastral terga directed posteriorly.

Gyne

Non-type measurements: EL 0.40, HL 2.30-2.40, HoW 1.50, HvW 1.50, HW 1.70-1.80, ML 1.20, SL 2.00-2.10, PnW 1.30, WL 3.20-3.60, FL 2.10-2.20, PTH 1.20, PTL 0.50, PtW 0.50, GL 2.90-3.50, TL 10.00-10.30. CI 0.73- 0.75, MI 0.5-0.52, PtI 2.4, SI 0.83-0.91, VI 0.83-0.88 (n= 2).

Mesosoma. Pronotum slightly longer than high in lateral view, dorsal margin slightly concave; lateral margins converging anteriorly forming a neck in dorsal view; pronotal dorsum with regular transverse striae forming arcs directed posteriorly on lateral face. Subalar area conspicuous with pronotum. Mesoscutum anterior and dorsal margin forming single convexity in lateral view; with median sulcus anteriorly in dorsal view; regular longitudinal striae; striae between parapsidial line and parascutal area oblique, directed medially. Parapsidial line diverging anteriorly and very fine. Parascutal area smooth and shining. Notopropodeal sulcus scrobiculate. Axilla with micro-sculpture and longitudinal striae limited to anterior portion. Mesoscutellum smooth and shining with sparse punctures, median longitudinal carina weakly developed might be present. Metascutellum smooth and shining with sparse punctures, with longitudinal carina weakly developed.

Petiole. Conical node, anterior face straight to slightly convex.

Pilosity. Pubescence on mesosoma strongly curved, dense separated each other less than its length. Pubescence on mesoscutellum less dense.

Male

Paratype measurements: EL 0.58, HL 0.8, OW 0.12, OES 0.31, IOW 0,21 WL 2.5, FWL 4.5, PTH 0.7, PTL 0.4, PTW 0.4, GL 2.3 TL 6.0. PtI 1.75 (n= 1).

Color and size. Head and mesosoma dark brown almost black. Petiole and coxae dark brown.Antenna. mandible and trochanter yellowish. Femur. Tibiae and gaster brown. Tarsi whitish. Relatively small size.

Pilosity. Head and mesosoma with dense appressed pubescence. Mesoscutum, mesoscutellum, petiole and gaster pubescence less dense, posterior face of petiole without pubescence. Pronotum with two pairs of thin erect hairs on posterior portion, one pair almost two times larger than the other. Thin and erect short hairs on posterior portion of gaster segments I and II, hairs on segments III, IV and V almost two times larger.

Head. Palp formula 5,3. Lateral ocelli partially surpassing posterior margin in frontal view; posterior margin between lateral ocelli slightly concave, not reaching median ocellus.

Mesosoma. Pronotal dorsum smooth and shining; with inconspicuous irregular transverse striae next to posterior margin in lateral view. Propleuron with micro sculpture. Mesoscutum smooth and shining. Axilla with micro sculpture. Mesoscutellum convex; smooth and shining. Metascutellum smooth and shining with longitudinal carina. Anepisternum smooth and shining. Katepisternum smooth and shining, posterior portion with micro sculpture. Metapleuron, metepisternum and propodeum with coarse rugae, space between them densely punctate. Metapleuron and propodeum separated by longitudinal sulcus scrobiculate. Propodeal dorsum with coarse rugae; dorsal and posterior face delimited by coarser rugae standing out from the others; posterior face with coarse rugae.

Wing. Whitish translucid. 5 hamuli. Pterostigma whitish.

Petiole. Sessile; dorsal portion blunt; with micro sculpture limited to latero-ventral portion under spiracle height.

Natural history: Odontomachus chicomendesi occurs in the soil of secondary, riparian and ombrophilous Amazonian forests, from 200– 820 m. This species is frequently collected in leaf litter and pitfall samples. There are records of O. chicomendesi as prey of Eciton rapax Smith, 1855 , at that time considered as a variation of O. haematodus by Brown, (1976). Although workers of O. chicomendesi are relatively abundant in collections, few gynes were found.

Comments: Most examined specimens of O. chicomendesi were identified as either O. brunneus or O. haematodus . The relatively small size, conical petiolar node, and imbricate or almost smooth and shining gastral terga can explain these misidentifications. The petiolar node shape resembles that of O. haematodus , but just O. chicomendesi has acute projection directed ventrally on the anteroventral portion of mesopleuron and the metasternal process is closed forming a fine arc; whereas O. haematodus does not have acute projection on the anteroventral portion of mesopleuron and its metasternal process is bilobate forming a pair of spines.

The male is unique because it is the only species with a coarsely rugose propodeum and a black body with white tarsi. It was not possible to examine the petiolar sternum and subpetiolar process of the male due to the way it was mounted. Workers from Peru are usually darker and with the petiolar spine relatively less curved than populations from Brazil. Some specimens have the pronotum striae spiral-shaped, resembling the pattern in O. biumbonatus and O. xeta sp. nov. The body color varies from light brown to dark brown with yellowish legs. Even individuals from the same series show this variation.

Brown (1976) mentions specimens collected by Carl Rettenmeyer in Ecuador that were smaller than O. haematodus and shared some characters with O. brunneus . During a visit to the QCAZ, these specimens were examined and their identity as O. chicomendesi was confirmed. The males present in this collection correspond to the paratype morphology with some variation in body color, usually with a lighter gaster.

Material examined: 130☿, 2♀. BRAZIL: Acre: Cruzeiro do Sul (11☿) . Amazonas: Benjamin Constant (17☿) ; BR 319, Km 450 (1☿) ; Manaus (1☿) . Maranhão: João Lisboa (2☿) . Pará: Belém (1☿) ; Carajás (3☿) ; Marabá (40☿, 2♀) ; Santarém (12☿) . Rondônia: Itapuã do Oeste (1☿) ; Ouro Preto do Oeste (1☿) ; Porto Velho (3☿) . Tocantins: Babaçulandia (4☿) ; Dois Irmãos (1☿) . ECUADOR: Napo: Limoncocha (6☿) ; Morona-Santiago: Los Tayos (8☿) .

GUYANA: [Cuyuni-Mazaruni]: Kartabo (5☿) . PERU: Cusco: Estación Biológica Vila Carmen (3☿) . Madre de Dios: Puerto Maldonado (10☿) .

Figures

FIGURE 15. Meso and metanotal striation of Odontomachus workers in dorsal view. A, mesonotum with longitudinal striae, mesometanotal sulcus vestigial (O. caelatus); B, mesonotum with transverse striae, mesometanotal sulcus scrobiculate (O. bauri). White squares with lines representing the striation pattern of mesonotum.

FIGURE 16. Pronotum shapes and mesonotal striation of Odontomachus workers in lateral view. A, pronotum angular, mesononotum striae curved anteriorly, forming lateral concentric arcs (O. caelatus); B, pronotum in lateral view convex, mesonotum striae not forming concentric arcs (O. scalptus). White squares with lines representing the striation pattern of mesonotum in lateral view and dash lines highlighting pronotum shapes.

FIGURE 18. Anterior face of petiolar nodes of Odontomachus workers in lateral view. A, bluntly angular, vertical anterior margin of petiolar node in lateral view longer than the half-length of petiolar sloping margin (O. chelifer); B, bluntly angular, vertical anterior margin of petiolar node in lateral view shorter than 1/3 length of petiolar sloping margin (O. bradleyi); C, conical (O. meinerti). Dash lines highlighting anterior face shape.

FIGURE 19. Metaesternal process of Odontomachus workers in ventral view, middle coxae on superior portion and hind coxae on inferior portion. A, metasternal process forming a pair of lateral cuticular borders widely separated each other (O. chelifer); B, metaesternal process forming a pair of triangular lobes almost as long as wide (O. dubius sp. nov.).

FIGURE 22. Metaesternal process of Odontomachus workers in ventral view, middle coxae on superior portion and hind coxae on inferior portion. A, metasternal process open, posterior border deeply invaginated anteriorly forming two lobes (O. biumbonatus); B, metaesternal process close, cuticle border forming bilobate projections (O. xeta sp. nov.). Dash lines highlighting the metasternal process shapes.

FIGURE 23. Odontomachus workers in lateral view. A, O. biolleyi (CASENT0907425, imaged by: Ziv Lieberman, Source: AntWeb.org. B, O. insularis. Arrows pointing to the petiole node spines.

FIGURE 25. Mesopleuron of Odontomachus workers in lateral view. A, mesopleuron with anteroventral portion forming acute projection directed ventrally of (O. chicomendesi sp. nov.); B, mesopleuron without anteroventral portion forming acute projection directed ventrally of (O. cupreus sp. nov.). Dash lines highlighting the mesopleuron shape.

FIGURE 30. Petiolar node of Odontomachus gynes in lateral view.A, bluntly angular node, vertical anterior margin of petiolar node almost 1/3 length of petiolar sloping margin node (O. chelifer); B, bluntly angular node, vertical anterior margin of petiolar node in lateral view almost as long as the petiolar sloping margin (O. bradleyi); C, conical node (O. chicomendesi sp. nov.). Dash lines highlighting the shape of anterior portion of petiole node.

FIGURE 34. Metascutellum striae of Odontomachus gynes in dorsal view. A, with longitudinal striae weakly impressed (O. laticeps); B, smooth and shining (O. scalptus); C, with longitudinal striae well-marked converging posteriorly (O. caelatus). Arrows pointing to the mesoscutellum.

FIGURE 37. Mesosoma of Odontomachus gynes in lateral view. A, mesopleuron with anteroventral portion forming an acute projection directed ventrally (O. chicomendesi sp. nov.); B, mesopleuron anteroventral portion not forming a blunt projection directed ventrally (O. bauri). Dash lines highlighting the mesopleuron shape.

FIGURE 38. Petiolar nodes of Odontomachus males in lateral view. A, pedunculate (O. hastatus); B, sessile with anterior face strongly convex (O. chelifer); C, sessile with anterior face slightly convex (O. affinis). Dash lines highlighting the shape of anterior face of petiole node.

FIGURE 39. Mesoscutellum shapes of Odontomachus males in antero-dorsal view. A, concave (O. chelifer); B, convex (O. haematodus). Dash lines highlighting the mesoscutellum shape.

FIGURE 41. Petiolar nodes of Odontomachus males in latero-oblique view. A, apex pointed, posterior portion not forming blunt projection and subpetiolar process with vestigial blunt lobe (O. xeta sp. nov.); B, apex blunt, posterior portion with lateral blunt projections and subpetiolar process with well-developed lobe (O. biumbonatus). Dash lines highlighting the posterior face projections and subpetiolar lobe shapes.

FIGURE 45. Mesoscutum sculpturing of Odontomachus males in dorsal view. A, smooth and shining (O. chicomendesi sp. nov.); B, with micro sculpture of striate aspect (O. haematodus).

FIGURE 59. Odontomachus biolleyi holotype. CASENT0907425, imaged by: Ziv Lieberman, Source:AntWeb.org.A, head in frontal view; B, full dorsal view; C, full lateral view.

FIGURE 60. Map of distribution of O. spissus, O. biolleyi, O. insularis and O. mormo. Triangles representing the typelocalities.

FIGURE 61. Odontomachus biumbonatus worker. A, head in frontal view; B, full lateral view; C, metasternum in ventral view with middle coxae at superior portion and hind coxae at inferior portion; D, mesosoma in dorsal view; E, petiole in lateral view; F, gaster in dorsal view.

FIGURE 62. Odontomachus biumbonatus gyne. A, head in frontal view; B, mesosoma in dorsal view; C, full lateral view.

FIGURE 63. Odontomachus biumbonatus male.A, head in frontal view; B, mesosoma in dorsal view; C, propodeum in posterior view; D, full lateral view.

FIGURE 64. Map of distribution of O. biumbonatus, O. opaciventris and O. xeta sp. nov. Triangles representing the typelocalities.

FIGURE 65. Odontomachus bradleyi worker.A, head in frontal view; B, full lateral view; C, metasternum in ventral view with middle coxae at superior portion and hind coxae at inferior portion; D, mesosoma in dorsal view; E, petiole in lateral view; F, gaster in dorsal view.

FIGURE 66. Odontomachus bradleyi gyne. A, head in frontal view; B, full dorsal view; C, petiole in lateral view; D, anterior and posterior wings in full view. Imaged by: Adrian Troya.

FIGURE 67. Map of distribution of O. chelifer, O. bradleyi and O. dubius sp. nov. Triangles representing the type-localities.

FIGURE 68. Odontomachus caelatus worker.A, head in frontal view; B, full lateral view; C, metasternum in ventral view with middle coxae at superior portion and hind coxae at inferior portion; D, mesosoma in dorsal view; E, petiole in lateral view; F, gaster in dorsal view.

FIGURE 70. Odontomachus caelatus male. A, head in frontal view; B, mesosoma in dorsal view; C, propodeum in posterior view; D, full lateral view.

FIGURE 71. Map of distribution of O. scalptus, O. yucatecus and O. caelatus. Triangles representing the type-localities.

FIGURE 72. Odontomachus chelifer worker. A, head in frontal view; B, full lateral view; C, metasternum in ventral view with middle coxae at superior portion and hind coxae at inferior portion; D, mesosoma in dorsal view; E, petiole in lateral view; F, gaster in dorsal view.

FIGURE 73. Odontomachus chelifer gyne. A, head in frontal view; B, mesosoma in dorsal view; C, full lateral view.

FIGURE 74. Odontomachus chelifer male. A, head in frontal view; B, mesosoma in dorsal view; C, propodeum in posterior view; D, full lateral view.

FIGURE 76. Odontomachus chicomendesi gyne. A, head in frontal view; B, mesosoma in dorsal view; C, full lateral view.

FIGURE 77. Odontomachus chicomendesi male paratype.A, head in frontal view; B, mesosoma in dorsal view; C, propodeum in posterior view; D, full lateral view.