Odontomachus chelifer ( Latreille, 1802 )

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 : 12-44

Odontomachus chelifer ( Latreille, 1802)

= Odontomachus chelifer leptocephalus Emery, 1890

= Odontomachus chelifer theresiae Forel, 1895

= Odontomachus chelifer emacerata Santschi, 1922

Odontomachus chicomendesi França, Fernandes & Lattke new species Odontomachus cornutus Stitz, 1933

Odontomachus cupreus França, Fernandes & Lattke new species Odontomachus davidsoni Hoenle, Lattke & Donoso, 2020 Odontomachus dubius França, Fernandes & Lattke new species Odontomachus erythrocephalus Emery, 1890

= Odontomachus biolleyi subsulcatus nomen nudum

Odontomachus haematodus ( Linnaeus, 1758)

= Odontomachus maxillosus ( De Geer, 1773)

= Odontomachus hirsutiusculus Smith, 1858

= Odontomachus haematodus pallipes Crawley, 1916

= Odontomachus haematodus brunneipes Menozzi, 1935 Odontomachus hastatus ( Fabricius, 1804)

= Odontomachus maxillaris Smith, 1858

Odontomachus insularis Guérin-Méneville, 1844

Odontomachus laticeps Roger, 1861

Odontomachus meinerti Forel, 1905

= Odontomachus minutus Luederwaldt, 1918

= Odontomachus haematodus dulcis Mann, 1922

Odontomachus mormo Brown, 1976

Odontomachus opaciventris Forel, 1899

Odontomachus panamensis Forel, 1899

= Odontomachus mayi Mann, 1912 new status

Odontomachus ruginodis Wheeler, 1908

Odontomachus scalptus Brown, 1978

Odontomachus spissus Kempf, 1962

Odontomachus xeta França, Fernandes & Lattke new species Odontomachus yucatecus Brown, 1976

Order: Hymenoptera Linnaeus, 1758 Family: Formicidae Latreille, 1802 Subfamily: Ponerinae Lepeletier de Saint-Fargeau, 1835 Tribe: Ponerini Lepeletier de Saint-Fargeau, 1835 Genus: Odontomachus Latreille, 1804

Odontomachus Latreille, 1804: 179 , type-species: Formica haematoda by monotypy; combination in Ponérites by Saint-Fargeau, 1835: 185; combination in Poneridae by Smith, 1858: 64 ; combination in Formicidae : Odontomachidae by Mayr, 1862: 711 ; combination in Ponerinae by Dalla Torre, 1893: 49, 51; combination in Odontomachini by Forel, 1893b: 163; combination in Ponerini : Odontomachiti by Brown, 1976: 70.

Pedetes Bernstein, 1861: 7 , type-species: Pedetes macrorhyncus by monotypy; junior synonym of Odontomachus by Dalla Torre, 1893: 51; incertae sedis in Odontomachus by Bolton, 1995: 296.

Champsomyrmex Emery, 1892: 558 (footnote), type-species Champsomyrmex coquereli by monotypy; combination in Ponerinae by Dalla Torre, 1893: 49; subgenera of Odontomachus by Forel, 1893b: 163; combination in Odontomachini by Emery, 1895: 768; status as genera by Emery, 1911: 111; junior synonym of Odontomachus by Brown, 1976: 96.

Myrtoteras Matsumura, 1912: 191, type-species: Myrtoteras kuroiwae by monotypy; combination in Odontomachini by Donisthorpe 1943: 672; junior synonym of Odontomachus by (W L Brown, 1976): 96.

Etymology: Masculine Greek compound name, odonto from odous = tooth and machus from makh ē= fight. Probably referring to the trap-jaw mandibles, meaning “fighting tooth”.

Diagnosis: (☿ and ♀) In frontal view, cephalic capsule pyriform. Vertex with median longitudinal furrow. Mandibles elongated anteriorly, apical portion with three teeth, masticatory margin with series of denticles. In dorsal-anterior view, occipital area with pair of apophyseal lines converging anteriorly with occipital carina in acute angle. Propodeum striate to rugose. Petiolar node always conical. (♂) Notauli absent. Anapleural sulcus present; propodeum usually with coarse sculpturing contrasting with the mesosoma sculpturing; petiolar node conical with apex usually acute.

Worker

Head. Cephalic capsule longer than wide in frontal view; anterior portion separated from vertex by often conspicuous cephalic constriction. Anterior head portion narrower anteriorly, wider medially at ocular prominence height and posteriorly delimitated by cephalic constriction. Clypeus fused to cephalic capsule; anterior margin slightly rounded; lateral portion with lobe covering mandible insertion; smooth and shining or micro-sculptured. Malar area smooth and shining or micro-sculptured. Frontal lobe covering antennal insertion, partially separated each other by frontoclypeal area. Frontal carina projecting posteriorly or not. Antennal scrobe shallow, shaped-like inverted “U”. Eye rounded to elliptical; posterior margin rounded or acute. Vertex varying from trapezoidal with anterior portion wider than posterior, lateral margins converging posteriorly, long ( Fig. 6-A ) or short in length ( Fig. 6- C ); or rectangular, with anterior and posterior portion almost or equally wide, lateral margins parallel ( Fig. 6-B ); posterior margin straight or medially concave. Ocular bridge protruding from vertex surface posteriorly forming angle or arch linking both ocular prominences. Regular longitudinal striae extend diagonally from frontal lobe to ocular bridge, reaching or not posterior head margin. Median furrow converging posteriorly with occipital carina and apophyseal lines. Occipital carina projecting or not from vertex surface forming nuchal collar. In dorsal view, occipital area with pair of dark apophyseal lines converging anteriorly with occipital carina and median furrow. In ventral view, hypostoma with pair of acute denticles projected anteriorly, longer than wide. Postgenal suture discontinuous anteriorly. Occipital carina extending anteriorly toward anteroventral apophyseal line. Ventral surface smooth and shining.

Mandible. Flattened dorsal-ventrally; as long as anterior portion of head or more ( Fig. 6-A ) or shorter ( Fig. 6-B and 6-C ). Apical portion curving ventrally in lateral view, with three acute teeth, usually worn. In dorsal view, dorsal apical tooth wider; intercalary tooth smaller than dorsal and ventral teeth; ventral tooth robust longer and wider. Masticatory margin with serial denticles or crenulations directed apically or not. External margin straight, slightly or strongly curved. Dorsal surface with inconspicuous transverse to oblique, irregular striation; sparse piligerous punctures present. Mandibles can open to 180° angle with each other and when closed, one apical portion overlaps with the other and basal margins are parallel.

Antenna. With twelve antennomeres, entirely punctate. Scape flattened dorsal-ventrally, slightly curved and wider medially; length varying, surpassing or not posterior margin of head. Basal portion of pedicel narrower than its apical portion, shorter than first flagellomere. Flagellomeres longer than wide, shortening gradually toward apex, distal flagellomere elliptical with acute apex.

Mesosoma. Pronotum and mesonotum in dorsal view, separated by rounded promesonotal suture. Notopropodeal sulcus separating mesonotum from metanotum sometimes shallow to weakly developed; smooth and shining, scrobiculate or longitudinally striated. Transverse declivity between metanotal spiracles separate metanotum from propodeum or surface between them continuous. Pronotum in lateral view varying from triangular, dorsal face weakly convex to almost straight ( Fig. 6-D ); to angular, with lateroposterior corner forming blunt projection and anterior face forming an obtuse angle with weakly convex dorsal face ( Fig. 6-E ); or rounded, dorsal face strongly convex ( Fig. 6-F ). In dorsal view, lateral margins straight and converging anteriorly, cervical area continuous to pronotum; or pronotum constricted anteriorly, forming neck with parallel lateral margin. Central disc of pronotum with different patterns of striation extending to lateral portions, cervical region or neck with transverse regular striae. Propleuron in ventral view with rounded lateral margin gradually converging anteriorly to the cervical area; cervical area with regular oblique striae that might extend to lateral margin, central portion smooth and shining, to finely striated. Prosternum triangular; posterior portion bilobate or slightly notched medially, longer than wide or as wide as long; smooth and shining or deeply punctuate. Mesonotum higher anteriorly in lateral view; in dorsal view, almost as long as wide or much wider, with regular striae longitudinal or transversely directed. Mesopleuron anteriorly elongated, anteroventral portion with rounded carina, forming acute projection directed ventrally or rounded lobe directed laterally; usually with regular transverse striae on anterior and posterior portions, median portion smooth and shining. Mesometanotal sulcus vestigial, forming shallow impression, or well-marked, smooth and shining to scrobiculate. Metanotum well-developed, almost as long as half-length of mesonotum, or vestigial, limited to narrow region between metanotal spiracles. Metanotal spiracle shaped ovoid or elliptical plate; usually smooth and shining. Metapleural-propodeal suture complete, weak or vestigial at mid-length. Propodeum without projections; dorsal margin straight, convex or with one or two shallow impressions in lateral view; dorsal margin gradually joining with posterior margin. Transverse, regular striae on propodeum extend to metapleuron, oblique and thicker posteriorly. Metapleural gland convex, protruding from metapleuron; opening simple, directed posteriorly in median portion of bulla, connected posteriorly by cuticle border that delimits the propodeal lobe; sculpture variable. Metasternum with posterior cuticle border forming open metasternal process, separated medially in two lateral portions; or metasternal process closed, with posterior border forming single arch that sometimes projects as lobe; smooth and shining with coarse sparse transverse striae, deeply punctate.

Legs. Tibiae flattened laterally. Tibiae and femora usually slightly reticulate, almost smooth and shining. Basitarsus longer than the length sum of other tarsomeres. Pretarsal claw simple. Arolium absent. Pectinate spur present on all tibiae; mesotibial spur with coarse pecten, resembling comb, its length half that of pro and metatibial spurs; pro and metatibial spurs feather like. Anterior leg longer than middle and posterior legs.

Petiole. Pedunculate, anterior portion anteriorly elongated ( Fig. 6-G ), varying in length; or sessile, at most presenting vestigial constriction between node and articulation with propodeum ( Fig. 6-H–J ). Node of petiole varying from angular, in lateral view with short vertical anterior section and long slope to summit ( Fig. 6-H ); to cylindrical, dorsal portion as wide as ventral portion with anterior and posterior faces strongly convex dorsally ( Fig. 6-I ); or conical, anterior and dorsal face forming a single surface, straight to convex ( Fig. 6-J ). Petiolar spine varying in shape and size from vestigial and blunt to acute and long, straight or curved posteriorly. Posterior face of petiole usually strongly convex at apex forming base of petiolar spine with concavity above it. Subpetiolar process varying from longer than wide, blunt or acute to wider than long, convex anteriorly or keel shape-like. Entirely smooth and shining, partially or completely striated, striae varying in thickness, direction, with or without punctures.

Gaster. In lateral view, first tergum longer than high or almost higher than long; anterior and dorsal margins form single convexity ( Fig. 6-K ) or anterior margin straight, forming blunt angle with dorsal convex margin ( Fig. 6-L–M ). Constriction between first and second segments weak. Sculpturing on first and second tergum varying according to species, third and fourth tergum usually less sculptured. Epipygium smooth and shining. Gastral sternum smooth and shining. Sting long and dorsally curved.

Color and size. Varying from small (TL minimum= 7.30 mm) with short appendages to large (TL maximum= 19.5 mm) and slender ants with long appendages). Head, mesosoma, petiole and gaster concolorous, or gaster darker than the head and body color or head color lighter, contrasting with body color. Antenna and legs usually lighter than body, testaceous to yellowish.

Pilosity. Light brown hairs distributed throughout body varying in size, density, orientation and inclination. Mandible with short hairs on dorsal face, length about equal to width of mandible base, inserted in punctuations, decumbent and directed apically; two or three pairs of long hairs present on ventral face, length about equal to mandible half-length or more, transversely directed; apex with hairs as long as apical tooth or more, decumbent and transversely directed. Two or three long, suberect, curved hairs present on posterior portion of frontal area anterior to cephalic constriction. Anterior margin of clypeus and lateral portion of anterior margin of head with short yellowish hairs directed anteriorly. Pronotum with series of long, suberect, curved hairs with length similar to pronotum height, varying in number and orientation. Propleuron with subdecumbent to suberect hairs varying in length. Procoxa with long erect hairs varying in length. Gaster with posteriorly directed hairs varying in number and inclination. Epipygium with pair of suberect, dorsal-laterally curved hairs, standing out from others. Tibia with long setae on apex, length about equal to tibia width, varying in number. Anterior basitarsus with dense short setae of different inclinations, their length less than basitarsus width, with a shining pubescent aspect. Light yellowish pubescence present on most body surface, varying in length, density, orientation and inclination.

Gyne

Resembling workers, differing by usual features associated with flight.

Mesosoma. Pronotum in lateral view varying from longer than high, dorsal margin straight ( Fig. 7-A ); to higher than long, dorsal face straight ( Fig. 7-B ), with broad anterior concavity and narrow posterior convexity ( Fig. 7-C ); or mostly broadly convex ( Fig. 7-D ); in dorsal view, lateral margins straight and converging anteriorly, cervical area continuous to pronotum ( Fig. 7-A ); or pronotum constricted anteriorly forming neck with parallel lateral margins ( Fig. 7 -B-D). Mesoscutum in dorsal view rounded anteriorly, longer than wider or as long as wide; notauli absent; parapsidial lines and parascutal carina present; in lateral view with short, almost vertical anterior margin that sharply curves onto horizontal dorsal margin ( Fig. 7-A ), or anteriorly convex curving onto dorsal margin ( Fig. 7-B ), or broadly convex ( Fig. 7 -C-D). Tegula drop-like shaped. Scutoscutellar sulcus well-developed. Mesoscutellum in dorsal view trapezoidal, wider anteriorly, longer than wide. Metascutellum wider than long with or without median longitudinal carina.

Wing. Color varying from dull grey, light brown or translucid pale yellow. Posterior margin of fore and hind wing, including jugal lobe, with short translucid setae. Wing surfaces with bristles as long or shorter than pilosity on body surface, always slender, visible by contrast on stereomicroscope. Pterostigma usually darker than wing surface or almost concolorous with it. Forewing ML1 curved ( Fig. 7-A ), slightly curved ( Fig. 7-B ) to almost straight ( Fig. 7 -C-D). RsL1 slightly curved ( Fig. 7 -A-B) to straight ( Fig. 7 -C-D); as long as Rs+M ( Fig. 7-A, B, D ), or shorter than Rs+M half-length ( Fig. 7-C ). RsL2-3 sinuous ( Fig. 7-A ) or curved to almost straight ( Fig. 7-B, C, D ). RS+M and ML2 meeting with RSL 2-3 in an obtuse angle, giving discal cell pentagonal shape ( Fig. 7-A ); or RS+M and ML2 forming single straight or curved line ( Fig. 7-B, C, D ). Vein cu-a reaching discal cell on M+Cu - ML1 angle ( Fig. 7-A ) or not reaching ( Fig. 7-B, C, D ). Hindwing RL vein reaching costal margin, becoming effaced toward apex. Hamuli varying in number from six to thirteen.

Petiole. Usually higher than long, spine more robust and sculpturing slightly coarser than worker.

Pilosity and sculpturing. Varying according to the species.

Male

Head. In frontal view, elliptical, wider than long. Frontal triangle delimited by frontal carina. Compound eye occupying more than 2/3 of head length, internal margin concave. Clypeus trapezoidal, posterior margin wider than anterior margin. Tentorial pit present. Lateral ocelli smaller than or same size as median ocellus; surpassing or not posterior margin of head in frontal view ( Fig. 4-E ). In dorsal view, occipital carina well-marked.

Mandible. Spatulate and short, as long or shorter than clypeus length; Masticatory margin without teeth; in lateral view, apical portion acute or blunt; in dorsal view with oblique carina, concave laterally. Palp formula 5,3 or 4,2; maxillary palps twice longer than labial palps.

Antenna. With thirteen antennomeres. Antennal insertion conspicuous, bulbous visible. Scape short, length about 1/3 or 1/4 of first flagellomere length. Pedicel short, ring-like, length about half-length of scape or less. Flagellum long, surpassing or almost surpassing mesosoma when directed posteriorly.

Mesosoma. Pronotum in dorsal view short, wider than long, arched posteriorly; postero-ventral portion concave in lateral view. Subalar area separated from pronotum by shallow sulcus or continuous to it. Mesoscutum, mesoscutellum and metascutellum as in gyne; sculpturing variable according to species. Notauli absent. Tegula twice longer than wide. Mesoscutellum in lateral view, rounded and dorsally projected. Anapleural sulcus present; katepisternum rounded and convex ventrally. Mesometapleural suture present, metepisternum separated from propodeum. Sculpturing for each sclerite varying from smooth and shining to microsculptured or striated.

Legs. As in worker and gyne. Tarsal claw with or without preapical tooth. Arolium and manubrium present and well-developed.

Wings. As in gyne but with wing membrane lighter and veins thinner.

Petiole. Pedunculate or sessile. Petiolar node conical, longer than high or as long as high; dorsal portion acute or blunt. Subpetiolar process triangular and varying in size.

Gaster. In dorsal view, elliptical with convex lateral margin or cylindrical with slightly convex, almost straight lateral margins. First tergite shortest.

Pilosity. Dense pubescence present on postero-lateral portion of head. Clypeus, frontal triangle, and frons between eyes and antennal insertions mostly with ventrally directed, dense, light pubescence; occasional thin hairs twice as high as pubescence. Pilosity and pubescence on gastral terga limited to posterior portion.

Comments: Among the Ponerinae ants, the only genus that looks like Odontomachus and can eventually be confused for it is Anochetus Mayr, 1861 . In general, the Odontomachus head has a relatively longer vertex than Anochetus . The posterior cephalic margin is straight or slightly concave, forming an acute angle with the occipital carina and the median furrow. Also, Odontomachus always has a pair of dark apophyseal lines in the occipital area, that converge anteriorly with the occipital carina and the median furrow. On the other hand, Anochetus has the vertex relatively short, the median furrow and the apophyseal lines are absent, and the posterior margin of the head is always deeply concave with the occipital carina very rounded.

It is common to find species with small body lengths like O. meinerti or O. spissus identified as Anochetus but they can be quickly recognized by the pair of apophyseal lines in the occipital area. The only species of Anochetus that might be confused with Odontomachus is Anochetus hohenbergiae Feitosa & Delabie, 2012 due to its conical petiolar node. Even so, the lack of apophyseal lines is enough to recognize it as Anochetus .

The apical dorsal tooth in the mandibles is usually worn and difficult to measure, hence it is not useful as a diagnostic feature. The same usually happens with the teeth or denticles on the masticatory margin, and in contrast with Anochetus , in Odontomachus the number of teeth is not diagnostic. In some yellowish-pale specimens of O. meinerti and O. chicomendesi sp. nov. the dorsal apical tooth is broken and forms a concavity with acute lateral portions, resembling two little teeth.

The Odontomachus males can be quickly identified using the mesonotum and particularly the propodeal sculpturing and body color.Even with some variation, the body color seems to be stable within species.The metasternal process is very similar to the workers and queens, it is relatively smaller and presents less coarse sculpture. There is a variety of microsculptures that were not possible to describe with the stereomicroscope and SEM images would help to explore these characters. According to MacGown et al. (2014), the ocelli size is diagnostic for the Nearctic males, but for the Neotropical species that’s not valid. Fernandes et al. (in prep.) indicate the petiole node as low and subtriangular in the Neotropical species Anochetus orchidicola and A. inermis , with two protuberances on each side of the node, as in most workers and queens of the genus.

Key to identify the species of Odontomachus based on workers from the Neotropical region

1- Petiole in lateral view pedunculate ( Fig. 8-A ).............................................................. 2

1’- Petiole in lateral view sessile ( Fig. 8-B ).................................................................. 5 2 (1)- Posterior margin of vertex narrower than its anterior portion in cephalic frontal view, straight and slightly concave medially. Occipital carina forming nuchal collar ( Fig. 9-A; 9-B ). Slender ants............................................ 3

2’- Posterior margin of vertex almost as wide as its anterior portion in frontal view, rounded at occipital borders and deeply concave medially. Occipital carina not forming nuchal collar ( Fig. 9-C ). Robust ants............................... 4

3 (2)- Vertex smooth and shining in frontal view ( Fig. 9-A ). Central disc of pronotum smooth and shining or with inconspicuous transverse striae in dorsal view ( Fig. 10-A ). Body covered by sparse erect hairs................. Odontomachus hastatus

3’- Vertex striate in frontal view ( Fig. 9-B ). Central disc of pronotum with transverse and conspicuous striae in dorsal view ( Fig. 10-B ). Body not covered by erect hairs................................................ Odontomachus davidsoni

4 (2’)- Ocular prominences acute and projecting anteriorly ( Fig. 11-A ). Petiolar node without an anterior prominence in lateral view. First tergum of gaster with long hairs and dense pubescence............................... Odontomachus cornutus

4’- Ocular prominences rounded and not projecting anteriorly ( Fig. 11-B ). Petiolar node with a blunt anterior prominence in lateral view. First tergum of gaster without hairs and with inconspicuous pubescence............. Odontomachus mormo 5 (1’)- Vertex smooth and shining in cephalic frontal view ( Fig. 9-A )................................................. 6

5’- Vertex with longitudinal striae in cephalic frontal view ( Fig. 9-B ).............................................. 9

6 (5)- Reduced eyes (EL= 0.2 mm). Scape not reaching the posterior head margin in cephalic frontal view ( Fig. 12-A ). Petiolar node scale-like. Small ants (TL<7.9 mm)................................................... Odontomachus spissus

6’- Not reduced eyes (EL> 0.3 mm). Scape surpasses the posterior head margin in cephalic frontal view ( Fig. 12-B ). Petiolar node conical. Medium to large ants (TL> 9.1 mm).............................................................. 7

7 (6’)- Central disc of pronotum with longitudinal striae that never form angles anteriorly. Petiolar node with posterior margin rounded and projecting laterally; dorsal portion of anterior face convex; petiolar spine relatively short and robust ( Fig. 13- A )............................................................................. Odontomachus allolabis

7’- Central disc of pronotum without longitudinal striae, if present, then they form obtuse angles anteriorly. Petiolar node with posterior margin at most slightly convex but never projecting laterally; dorsal portion of anterior face straight to slightly concave; petiolar spine relatively long and slender ( Fig. 13-B )................................................ 8

8 (7’)- Central disc of pronotum with curved transverse striae, outer striae forming concentric ellipses. Mesopleuron without anteroventral rounded lobe directed laterally in dorsal view ( Fig. 14-A )........................ Odontomachus affinis

8’- Central disc of pronotum with striae forming angles anteriorly, outer striae usually forming concentric triangles and circles. Mesopleuron with anteroventral rounded lobe directed laterally in dorsal view ( Fig. 14-B )..... Odontomachus panamensis

9 (5’)- Mesonotum in dorsal view with longitudinal striae. Mesometanotal sulcus vestigial, metanotum striae continuous with mesonotum striae ( Fig. 15-A )......................................................................... 10

9’- Mesonotum in dorsal view with transverse striae. Mesometanotal sulcus scrobiculate, metanotum striae not continuous with mesonotum striae ( Fig. 15-B )......................................................................... 12

10 (9)- Anterior margin of pronotum in lateral view angular. Mesonotal striae curved anteriorly, forming lateral concentric arcs ( Fig. 16-A ). First tergum of gaster with regular and posteriorly diverging longitudinal striae........... Odontomachus caelatus

10’- Anterior margin of pronotum in lateral view convex. Mesonotal striae not forming concentric arcs, at most slightly curved ( Fig. 16-B ). First tergum of gaster without striae, if present they are limited to the posterior portion and the anterior portion is punctate.......................................................................................... 11

11 (10’)- Mesopleuron with transverse striae on all surface, sometimes effaced centrally. First tergum of gaster in dorsal view densely punctate or anteriorly punctate and gradually becoming longitudinally striate posteriorly ( Fig. 17-A )... Odontomachus scalptus

11’- Mesopleuron with transverse striae restricted to the anterior and posterior portion, central portion smooth and shining. First tergum of gaster in dorsal view imbricate or almost smooth and shining ( Fig. 17-B )............ Odontomachus yucatecus

12 (9’)- Petiolar node in lateral view bluntly angular, with a short vertical anterior section and a long slope to the summit ( Fig 18- A–B ). Anterior margin of first gastral tergum in lateral view shorter than half the length of the dorsal margin.......... 13

12’- Petiolar node in lateral view conical, anterior face forming single surface to the summit ( Fig. 18-C ). Anterior margin of first tergum of gaster as long as the half length of the dorsal margin............................................... 15

13 (12)- Vertical anterior margin of petiolar node in lateral view shorter than 1/3 length of petiolar sloping margin, petiolar node relatively long ( Fig. 18-A ). Central disc of pronotum with longitudinal striae. First tergum of gaster imbricate, almost smooth and shining....................................................................... Odontomachus bradleyi

13’- Vertical anterior margin of petiolar node in lateral view longer than the half-length of petiolar sloping margin, petiolar node relatively short ( Fig. 18-B ). Central disc of pronotum with transverse striae. First gaster tergum with transverse striae... 14

14 (13’)- In ventral view, metasternal process forming a pair of lateral cuticular borders widely separated from each other, sometimes forming a pair of short blunt lobes close to the middle line ( Fig. 19-A ). Body color brown to light brown, if dark brown then appendages always yellowish........................................................ Odontomachus chelifer

14’- In ventral view, metasternal process forming a pair of triangular lobes, each almost as long as wide ( Fig. 19-B ). Body color dark brown to almost black with appendages slightly lighter.......................... Odontomachus dubius sp. nov.

15 (12’)- Posterior portion of ventral margin of pronotum in lateral view with anteriorly curved long hairs, almost as long as the anterior procoxal hairs ( Fig. 20-A ). Propleuron with long erect hairs, about two times longer than the length of the propleural pubescence ( Fig. 20-A ). Subpetiolar process not posteriorly concave......................... Odontomachus laticeps

15’- Posterior portion of ventral margin of pronotum in lateral view without long hairs ( Fig. 20-B ). Propleuron with short, decumbent hairs, slightly longer than the propleural pubescence ( Fig. 20-B ). Subpetiolar process posteriorly concave... 16

16 (15)- Petiolar node in lateral view cylindrical, dorsal portion almost as wide as ventral portion ( Fig. 21-A ). Lateral margins of vertex in frontal view parallel, not converging posteriorly................................................... 17

16’- Petiolar node in lateral view conical, dorsal portion narrower than ventral portion ( Fig. 21-B ). Lateral margins of vertex in frontal view converging posteriorly..................................................................... 19

17 (16’)- Eyes in frontal view rounded with obtuse posterior margin. First gastral tergum entirely deeply punctate............................................................................................ Odontomachus opaciventris

17’- Eyes in frontal view elliptical with acute posterior margin. First gastral tergum imbricate to smooth and shining........ 18

18 (17’)- Metasternum in ventral view with metasternal process open, posterior border deeply invaginated anteriorly forming two lobes, irregular and longitudinal striae present ( Fig. 22-A ). Petiolar node in lateral view smooth and shining, at most with effaced oblique striae on ventral portion............................................ Odontomachus biumbonatus

18’- Metasternum in ventral view with metasternal process close, cuticle border forming bilobate projections, densely punctate with irregular transverse striae ( Fig. 22-B ). Petiolar node in lateral view with fine irregular oblique striae that gradually efface dorsally...................................................................... Odontomachus xeta sp. nov.

19 (16’)- Petiolar node in lateral view with anterior margin not inclined posteriorly, almost forming a right angle ( Fig. 18-C ). First gastral tergum in dorsal view either with longitudinal striae, anteriorly punctate and posteriorly striate or slightly areolate.................................................................................. Odontomachus meinerti

19’- Petiolar node in lateral view with anterior margin inclined posteriorly, almost forming an angle of 45° with the horizontal axis ( Fig. 21-B ). First gastral tergum in dorsal view imbricate to smooth and shining................................. 20

20 (19’)- Body color yellowish, gaster slightly darker than head and mesosoma......................................... 21

20’- Body color not yellowish, gaster as dark as mesosoma or more............................................... 22

21 (20)- Scape surpassing occipital corner by more than pedicel length. Petiolar node in lateral view triangular, spine reduced to a blunt projection ( Fig. 23-A )............................................................... Odontomachus biolleyi

21’- Scape surpassing occipital corner by less than pedicel length. Petiolar node in lateral view with long, slender and curved spine ( Fig. 23-B )...................................................................... Odontomachus insularis

22 (20’)- Head ferruginous or yellowish, strongly contrasting with the dark brown to almost black body ( Fig. 24-A ). Petiolar node campanulate, sometimes with fine and inconspicuous striae.......................... Odontomachus erythrocephalus

22’- Head color not contrasting with body color ( Fig. 24-B ). Petiolar node conical, if campanulate, then with thick and conspicuous striae............................................................................................. 23

23 (22’)- Scape reaching or slightly surpassing occipital corner. Mesopleuron in lateral view with anteroventral portion forming an acute projection directed ventrally ( Fig. 25-A )................................ Odontomachus chicomendesi sp. nov.

23’- Scape usually surpassing occipital corner at least by half-length of pedicel. Mesopleuron in lateral view without anteroventral portion forming an acute projection directed ventrally ( Fig. 25-B )............................................ 24

24 (23’)- Head and mesosoma usually dark brown or black......................................................... 25

24’- Head and mesosoma usually reddish brown or ferruginous.................................................. 26

25 (24)- Metasternum in ventral view with metasternal process forming a pair of spines posteriorly ( Fig. 26-A ). Metasternum sculpture inconspicuous. Petiolar node in lateral view with straight anterior margin, striae on posterior face effaced or inconspicuous............................................................................ Odontomachus haematodus

25’- Metasternum in ventral view with metasternal process not forming a pair of spines ( Fig. 26-B ). Metasternum with coarse transverse striae. Petiolar node in lateral view usually campanulate, anterior margin convex on dorsal portion, posterior face with coarse and regular striae.......................................................... Odontomachus bauri

26 (24’)- Propleuron in ventral view with fine transverse striae, central portion usually effaced ( Fig. 27-A ). Posterior portion of procoxa usually with micro striae. Petiolar node punctate-striate............................. Odontomachus cupreus sp. nov.

26’- Propleuron in ventral view smooth and shining, coarse short striae limited to lateral margins ( Fig. 27-B ). Posterior portion of procoxa smooth and shining. Petiolar node striae without punctures......................... Odontomachus ruginodis

Key to identify the species Odontomachus based on gynes from the Neotropical region

OBS: Odontomachus biolleyi , O. dubius sp. nov., O. mormo , O. opaciventris and O. yucatecus were not included because they are unknown or it was not possible to examine their gynes. Even though the gyne of O. mormo is unknown we kept it on the key due to the stability of the diagnostic characters that separate the workers of it from O. cornutus .

1- Petiole in lateral view pedunculate ( Fig. 8-A ).............................................................. 2

1’- Petiole in lateral view sessile ( Fig. 8-B ).................................................................. 4

2- Posterior margin of vertex narrower than its anterior portion in cephalic frontal view, straight and slightly concave medially ( Fig. 9 -A-B). Ocular prominence rounded ( Fig. 11-B )....................................................... 3

2’- Posterior margin of vertex as wide as its anterior portion in frontal view, rounded at occipital borders and concave medially ( Fig. 9-C ). Ocular prominence acute and projected anteriorly ( Fig. 11-A )..................... Odontomachus cornutus

3 (2)- Vertex smooth and shining in frontal view ( Fig. 9-A ). First tergum of gaster with dense pubescence... Odontomachus hastatus

3’- Vertex striate in frontal view ( Fig. 9-B ). First tergum of gaster with inconspicuous pubescence.... Odontomachus davidsoni

4 (1’)- Vertex smooth and shining in frontal view ( Fig. 9-A )........................................................ 5

4’- Vertex with regular and longitudinal striae in cephalic frontal view ( Fig. 9-B ).................................... 8

5 (4)- Reduced eyes (EL= 0.3 mm). Scape not reaching the posterior margin of the head in frontal view ( Fig. 12-A ). Petiolar node scale-like. Small ants (TL<7.9 mm).................................................... Odontomachus spissus

5’- Not reduced eyes (EL≥ 0.4 mm). Scape surpassing the posterior margin of the head in frontal view ( Fig. 12-B ). Petiolar node conical. Medium size ants (TL> 9.1 mm)................................................................. 6

6- Pronotum in lateral view with concave dorsal margin. Mesoscutum, mesoscutellum and axillae smooth and shining ( Fig. 28- A ). Posterior margin of petiolar node rounded and projecting laterally....................... Odontomachus allolabis

6’- Pronotum in lateral view with straight dorsal margin. Mesoscutum, mesoscutellum and axillae with longitudinal striae ( Fig. 28-B ). Posterior margin of petiolar node slightly convex, but not projecting laterally............................... 7

7 (6’)- Pronotum striae in lateral view regular. Propleuron without hairs, at most with inconspicuous pubescence. Mesopleuron without anteroventral rounded lobe directed laterally in dorsal view ( Fig. 29-A )................. Odontomachus affinis

7’- Pronotum striae in lateral view irregular. Propleuron with suberect hairs. Mesopleuron with anteroventral rounded lobe directed laterally in dorsal view ( Fig. 29-B ).......................................... Odontomachus panamensis

8 (4’)- Pronotum with straight dorsal margin in lateral view. Petiolar node in lateral view bluntly angular, with a short vertical anterior section anteriorly ( Fig. 30 -A-B).................................................................. 9

8’- Pronotum with convex dorsal margin in lateral view or forming an obtuse angle posteriorly. Petiolar node in lateral view conical ( Fig. 30-C ).................................................................................. 10

9 (8)- Vertical anterior margin of petiolar node in lateral view almost 1/3 length of petiolar sloping margin ( Fig. 30-A ). Petiolar node anteriorly elongated. Gastral terga with transverse striae................................... Odontomachus chelifer

9’- Vertical anterior margin of petiolar node in lateral view almost as long as the petiolar sloping margin ( Fig. 30-B ). Petiolar node not anteriorly elongated. Gastral terga imbricate to smooth and shining................... Odontomachus bradleyi

10 (8’)- Propleuron in ventral view with conspicuous striae, striae on central portion might be effaced, concentric or form arcs ( Fig. 31-A )............................................................................................ 11

10’- Propleuron in central view smooth and shining, if striae are present, they are vestigial and restricted to the lateral margins ( Fig. 31-B )............................................................................................ 16

11 (10)- Dorsal margin of pronotum in lateral view anteriorly concave forming obtuse angle posteriorly ( Fig. 32-A ). Body dark brown........................................................................................... 12

11’- Dorsal margin of pronotum in lateral view, anteriorly straight becoming convex posteriorly ( Fig. 32-B ). Body reddish brown................................................................... Odontomachus cupreus sp. nov.

12 (11)- Pronotum dorsum with striae on median portion next to posterior margin strongly curved, forming concentric arcs directed anteriorly ( Fig. 33-A ); in lateral view, ventral margin of pronotum with series of short, curved hairs directed anteriorly... 13

12’- Pronotum dorsum with striae on median portion next to posterior margin weakly curved, not forming concentric arcs directed anteriorly ( Fig. 33-B ); in lateral view, pronotum without series of short curved hairs directed anteriorly............... 14

13 (12)- Mesoscutellum with weakly impressed longitudinal striae, sometimes laterally effaced ( Fig. 34-A ). Petiolar node in lateral view with slightly concave anterior margin. Gastral terga smooth and shining to longitudinally striate.................................................................................................. Odontomachus laticeps

13’- Mesoscutellum smooth and shining ( Fig. 34-B ). Petiolar node in lateral view with anterior margin straight. Gastral terga densely punctate-striate, punctures on anterior portion gradually becoming longitudinal striae..... Odontomachus scalptus

14 (12’) Mesoscutum pubescence inconspicuous, almost absent. Mesoscutellum with regular and well-marked longitudinal striae converging posteriorly ( Fig. 34-C ). Gastral terga with longitudinal striae diverging on posterior portion................................................................................................. Odontomachus caelatus

14’ Mesoscutum pubescence dense. Mesoscutellum in dorsal view with inconspicuous fine longitudinal to oblique striae ( Fig. 34-A ). Gastral terga in dorsal view smooth and shining to imbricate........................................... 15

15 (14’)- Metasternum with irregular fine longitudinal striae in ventral view, metasternal process open forming a pair of acute lobes posteriorly ( Fig. 22-B ). Petiolar node in lateral view with coarse irregular striae on ventral portion................................................................................................. Odontomachus biumbonatus

15’- Metasternum with irregular coarse transverse striae in ventral view, metasternal process close forming a bilobate projections ( Fig. 22-A ). Petiolar node in lateral view with fine irregular striae....................... Odontomachus xeta sp. nov.

16 (10’)- Axilla longitudinally striae ( Fig. 35-A ). Gastral terga in dorsal view areolate or punctate anteriorly and striate longitudinally................................................................................ Odontomachus meinerti

16’- Axilla smooth and shining or at most with effaced short striae on anterior portion ( Fig. 35-B ). Gastral terga in dorsal view smooth and shining to imbricate....................................................................... 17

17 (16’)- Head red to yellowish, contrasting with the dark brown almost black body ( Fig. 24-A )..... Odontomachus erythrocephalus

17’- Head light brown, slightly ferruginous to dark brown, not contrasting with the body color ( Fig. 24-B )................ 18

18 (17’)- Mesosoma and petiole light brown to yellowish. Petiole smooth and shining; petiolar spine slender and strongly curved posteriorly ( Fig. 36-A )............................................................. Odontomachus insularis

18’- Mesosoma and petiole dark brown to almost black. Petiole with coarse transverse striae ( Fig. 36-B ) or densely imbricate in lateral view ( Fig. 30-C ); petiolar spine robust, straight to slightly curved posteriorly.............................. 19

19 (18’)- Metasternal process forming a pair of spines posteriorly ( Fig. 26-A )....................... Odontomachus haematodus

19’- Metasternal process forming a pair of lobes, at most lip-like ( Fig. 26-B )........................................ 20

20 (19)- Mesopleuron in lateral view with anteroventral portion forming an acute projection ventrally directed ( Fig. 37-A ). Petiolar lateral face imbricate ( Fig. 30-C ), posterior margin with fine striae limited to ventral portion or completely smooth and shining............................................................... Odontomachus chicomendesi sp. nov.

20’- Mesopleuron in lateral view with anteroventral portion forming a blunt projection ventrally directed ( Fig. 37-B ). Petiolar lateral face with coarse transverse striae in lateral view ( Fig. 36-B ), posterior margin also coarsely striated................................................................................................ Odontomachus bauri

Key to identify the species of Odontomachus based on males from the Neotropical region

OBS: O. cornutus and O. panamensis were not included because males were not examined and the original descriptions do not provide diagnostic characters for them (respectively Kugler, 1980 and Forel, 1899).

1- Mesoscutum with transverse to oblique rugae. Petiole in lateral view pedunculate, longer than high ( Fig. 38-A ).......................................................................................... Odontomachus hastatus

1’- Mesoscutum with longitudinal to oblique striae or smooth and shining. Petiole in lateral view sessile, almost as long as high or higher than long ( Fig. 38-B and 38-C )................................................................. 2

2 (1’)- Mesoscutellum in antero-dorsal view concave ( Fig. 39-A ). Propodeal dorsum with fine regular striae diverging posteriorly.................................................................................................. 3

2’- Mesoscutellum in antero-dorsal view convex ( Fig. 39-B ). Propodeal dorsum with coarse irregular striae, usually with wrinkled aspect, if striae diverge posteriorly then the petiole apex is blunt............................................... 8

3 (2)- Mesoscutum and mesoscutellum conspicuously striae. Anterior margin of Petiolar node in lateral view strongly convex ( Fig. 38-B )........................................................................... Odontomachus chelifer

3’- Mesoscutum and mesoscutellum with inconspicuous micro sculpture. Anterior margin of Petiolar node in lateral view straight to slightly convex ( Fig. 38-C ).......................................................................... 4

4 (3’)- Body light brown to yellowish.......................................................................... 5

4’- Body dark brown sometimes with some areas lighter........................................................ 6

5 (4)- Mesoscutum with conspicuous oblique striae converging posteriorly. Dorsal and posterior face of propodeum separated by coarse striae; propodeum in posterior view without concentric striae ( Fig. 40-A )................. Odontomachus affinis

5’ Mesoscutum with inconspicuous oblique striae diverging on middle portion and converging in the posterior portion. Dorsal and posterior face of propodeum not separated by coarse striae; propodeum in posterior view with concentric striae ( Fig. 40- B ).............................................................................. Odontomachus laticeps

6 (4’)- Posterior portion of petiolar node in latero-oblique view weakly convex, petiolar node apex pointed. Subpetiolar process with vestigial, posterior blunt lobe ( Fig. 41-A )........................................... Odontomachus xeta sp. nov.

6’- Posterior portion of petiolar node in latero-oblique strongly convex, petiolar node apex blunt. Subpetiolar process with well-developed, posterior blunt lobe ( Fig. 41-B )................................................................ 7

7 (6’)- Mesoscutellum with longitudinal carina ( Fig. 42-A ). Dorsal and posterior face of propodeum not separated by coarse striae. Posterior face of propodeum with transverse striae........................................ Odontomachus caelatus

7’- Mesoscutellum without longitudinal carina ( Fig. 42-B ). Dorsal and posterior face of propodeum separated by coarse striae. Posterior face of propodeum without transverse striae................................. Odontomachus biumbonatus 8 (2’)- Propodeum in posterior view rugose. Petiolar node with apex acute in lateral view ( Fig. 43-A )....................... 9

8’- Propodeum in posterior view with striae forming concentric longitudinal arcs on middle portion, sometimes with transverse striae on lateral portion. Petiolar node with blunt apex in lateral view ( Fig. 43-B )............... Odontomachus meinerti

9 (8)- Petiolar node with striae oblique on the posterior portion ( Fig. 43-A ).......................................... 10

9’- Petiolar node without striae oblique on the posterior portion ( Fig. 43-B )........................................ 11

10 (9’)- Mesosoma dark-brown, head and gaster lighter. Central portion of mesoscutum with conspicuous oblique and irregular striae, posterior portion with coarse longitudinal striae ( Fig. 44-A ). Axilla with fine longitudinal striae................................................................................................. Odontomachus erythrocephalus

10’- Body color pale yellow with brown metascutellum and propodeum. Central portion of mesoscutum with effaced micro-sculpturing becoming coarser laterally, posterior portion without longitudinal coarse striae ( Fig. 44-B ). Axilla without fine longitudinal striae................................................................ Odontomachus insularis

11 (9’)- Mesoscutum in dorsal view smooth and shining ( Fig. 45-A ). Entire body black. Tarsi whitish.............................................................................................. Odontomachus chicomendesi sp. nov.

11’- Mesoscutum in dorsal view with micro-sculpture of striolate aspect ( Fig. 45-B ). Body pale yellow sometimes with brown spots and propodeum brown. Tarsi yellowish to light brown................................................. 12

12 (11’)- Metasternum with pair of spines ( Fig. 46-A )......................................... Odontomachus haematodus

12’- Metasternum without pair of spines, at most rounded lobes or pair of lateral cuticle borders ( Fig. 46-B )............... 13

13 (12’)- Mesoscutum with dark brown spots ( Fig. 47-A ). Head and mesosoma, except propodeum, pale yellow... Odontomachus bauri

13’- Mesoscutum at most with slightly darker areas never forming contrasting spots ( Fig. 47-B ). Head and mesosoma, except propodeum, ferruginous to light brown................................................ Odontomachus ruginodis

Odontomachus affinis Guérin-Méneville, 1844 ( Figures 8-B , 12-B , 14-A , 28-B , 29-A , 38-C , 40-A , 48 , 49 , 50 and 51 )

Odontomachus affinis Guérin-Méneville, 1844: 423 (☿); Roger, 1861: 27 (♀).

Type material: Syntype [Images]. BRESIL[ BRAZIL]: [no further data], [envoyé par M.] Pinel , (type), GBIF-D/ FoCol 0682, 1☿ [ ZSM] .

Etymology: From the Latin word affinis = related to, neighboring; referring to the similarity with O. chelifer .

Diagnosis: (☿) Vertex rectangular, smooth and shining. Central disc of pronotum in dorsal view with regular transverse striae slightly curved anteriorly. Petiolar node campanulate to conical, smooth and shining. Central disc of first tergum of gaster smooth and shining in dorsal view. (♀) Pronotum striae regular in lateral view. Mesopleuron anteroventral portion without rounded lobe directed laterally. (♂) Body color yellowish brown. Dorsal face of propodeum with regular striae diverging posteriorly towards propodeal spiracles.

Worker

Non-type measurements: EL 0.4-0.5, HL 2.7-3.6, HoW 1.9-2.9, HvW 1.4-2.1, HW 1.6-2.4, ML 1.7-2.1, SL 2.7-3.3, PnW 0.9-1.4, WL 3.3-4.4, FL 3.0-3.9, PTH 1.2-1.6, PTL 0.6-0.7, PTW 0.4-0.6, GL 2.9-4.5, TL 11.4-14.8. CI 0.56- 0.66, MI 0.54-0.65, PtI 1.85-2.50, SI 0.82-1.0, VI 0.84-0.94 (n= 30).

Head. Vertex rectangular to trapezoidal, in frontal view, length larger than its half-width; smooth and shining. Posterior margin concave medially; occipital carina not forming nuchal collar. Cephalic constriction conspicuous. Striae on frontal area reaching cephalic constriction and ocular bridges. Frontal lobes striated posteriorly. Ocular bridges posteriorly forming arch. Eye relatively large (EL> 0.4); rounded, posterior margin rounded. Clypeus wrinkly-punctate on median portion. Malar area smooth and shining in latero-oblique view.

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 triangular in lateral view, 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 mostly smooth and shining, regular oblique striae restricted to anterior portion. Mesonotum wider than long; regular transverse striae slightly arched 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 slightly scrobiculate. Metanotum with regular transverse striae curved anteriorly. Metapleural gland bulla smooth and shining. Propodeum in lateral view with shallow depression on middle length; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process open, cuticle border fine forming lateral projections; with regular transverse striae.

Petiole: Sessile. Node campanulate or conical with anterior margin slightly convex at dorsal portion. Spine acute, slightly curved posteriorly. Entire node surface smooth and shining, sometimes with weak lateroventral striae. Subpetiolar process longer than wide; tip blunt; posterior portion not concave.

Gaster: First tergum usually longer than high; anterior and dorsal margin meeting in a convex surface not forming an angle; dorsal face of all terga smooth and shining.

Color and size. Head, mesosoma and petiole ferruginous to orange. Gaster darker, leg and antenna lighter. Medium to relatively large size ants.

Pilosity. Scattered inconspicuous pubescence spread over the body. Anterior portion of pro-coxa with hairs shorter than coxal width; ventral portion of gaster with short hairs. Posterior half of gastral tergum with long erect hairs, directed posteriorly.

Gyne

Non-type measurements: EL 0.5-0.6, HL 3.2-3.6, HoW 2.4-2.7, HvW 1.8-2.1, HW 2.0-2.3, ML 1.9-2.2, SL 3.1-3.4, PnW 1.4-1.7, WL 4.5-4.8, FL 3.4-4.0, FWL 8.3-8.6, PTH 1.6-2.0, PTL 0.7-0.8, PTW 0.6-0.7, GL 4.2-5.5, TL 14.9- 16.7. CI 0.62-0.64, MI 0.58-0.61, PtI 2.0-2.5, SI 0.93-0.96, VI 0.85-0.91 (n= 6).

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 transverse and posteriorly convex striae on transition between dorsal and lateral face. Subalar area separated from pronotum by sulcus at least on dorsal portion; striae finer than on pronotum. Mesoscutum anterior and dorsal margins meeting in convex surface, form an almost rounded right angle; with anterior longitudinal depression, length about first flagellomere length in dorsal view; slightly wider than long, with regular longitudinal striae, medial striae converging posteriorly; striae between parapsidial line and parascutal area oblique, directed medially. Parapsidial line curved, well-marked. Parascutal area smooth and shining. Notopropodeal sulcus scrobiculate. Axilla with regular longitudinal striae, posteriorly effaced. Mesoscutellum smooth and shining with longitudinal carina. Metascutellum smooth and shining.

Wing. Color dull brown, darker on areas closer to veins. Fore wing ML1 slightly curved almost straight. RsL1 straight; almost as long as Rs+M. RSL2-3 slightly curved. Rs+M and ML2 forming single straight to 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. 10 hamuli.

Petiole. Node of petiole conical, anterior and posterior faces slightly convex.

Pilosity. Pubescence on pronotum and propodeum dense, separated from each other by about its own length. Pubescence on mesoscutum, mesoscutellum and metascutellum inconspicuous.

Male

Non-type measurements: EL 0.7-0.8, HL 1.0-1.2, IOW 0.1-0.2, OES 0.2-0.3, WL 3.2-3.8, FWL 6.1-7.3, PTH 0.9- 1.3, PTL 0.6-0.7, PTW 0.4-0.6, GL 2.7-4.2, TL 7.0-9.0. PtI 1.5-1.8 (n= 10).

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

Mesosoma. Pronotal dorsum mostly transversely striate; with micro sculpture effaced on central portion in lateral view. Propleuron smooth and shining. Mesoscutum anteriorly with transverse striae, striae on dorsal surface posteriorly converging. Axilla and mesoscutellum with micro sculpture and fine striae. Mesoscutellum medially concave. Metascutellum with micro sculpture, longitudinal carina present. Anepisternum smooth and shining. Katepisternum with dense micro sculpture. Metapleuron with fine irregular longitudinal striae. Metapleuron with sparse, oblique to longitudinal striae, coarser on central portion, with micro sculpture between them. Metepisternum mostly with oblique to curved sparse striae, with micro sculpture between them. Metapleuron and propodeum separated by longitudinal carina extending from metepisternum to propodeal spiracle, and by discontinuous and longitudinal striae posteriorly to it. Propodeal dorsum with oblique striae diverging posteriorly to propodeal spiracle; dorsal and posterior face of propodeum delimitated by short coarser striae; posterior face with piliferous punctures. Tarsal claw with pre-apical denticle.

Wing. Light brown. Hamuli varying from 7 to 10. Pterostigma light brown, slightly darker than rest of wing surface.

Petiole. Sessile; dorsal portion acute; coarsely imbricate on ventral portion gradually becoming smooth and shining dorsally. Subpetiolar process sub-quadrate. Sternum concave posteriorly.

Color and size. Entire body light brown to bright yellow. Relatively large.

Pilosity. Head, mesosoma and gaster with dense appressed pubescence. Petiolar pubescence less dense. Pronotum with thin erect hairs on posterior portion, two of them usually larger. Thin and erect short hairs on posterior portion of gaster segments I and II, hairs on segments III, IV and V larger almost twice longer.

Natural history: Odontomachus affinis nests in soil, rotten wood ( Brown, 1976), or under tree trunk bases ( Brandão, 1983). The underground nests may extend about 50 cm in depth and be about 30 cm in diameter, and the galleries are usually built along the root system of the tree under which the nest was built. The entrance has a mound made of leaf pieces and sticks ( Brandão, 1983). Young colonies can be found under partially rotten trunks with founding queens in a single chamber under the bark ( Brandão, 1983).

According to Brandão (1983), queens in young colonies display a larger behavioral repertory. As colonies grow, queens’ behavior is limited to egg production. Workers from colonies without queens or unfertilized gynes start to lay eggs. This suggests that queens have certain control over worker sterility. The average time of male egg development in artificial conditions is 59 (±3) days. Apparently, chemical communication is more important to queens than workers, since they do not display antennation behavior with workers. On the other hand, apparently, the combination of chemical and mechanical signals through antennation between workers is crucial to recognizing members from the same colony.

Brandão (1983) observed the following insects associated with O. affinis nests: Passalidae Leach, 1815 , Tenebrionidae Latreille, 1802 , a small colony of Heteroponera flava Kempf, 1962 , and workers of Armitermes Wasmann, 1987 .

Specimens of O. affinis have been collected with pitfall traps, Winkler’s extractor, and even at bait stations at night. Some specimens have been collected on stems of Tibouchina mutabilis (Vell.) Cogn. ( Melastomataceae ). Gynes and males have been collected at light and with Malaise traps. This species is endemic to the Atlantic Forest ( Fig. 51 ) and can be found in forest or urban green areas ( Brandão, 1983) from 50 m to about 1000 m above sea level.

Comments: Odontomachus affinis can be recognized due to the smooth and shining vertex, node of the petiole, and gastral terga smooth and shining. To the naked eye, darker specimens might be confused with O. chelifer . However, O. chelifer has the vertex and the gaster striate, and the petiolar node is slightly angular on the anterior face. The only other species with smooth and shining vertex and gastral terga is O. panamensis , which can be distinguished by the pattern of striation on the pronotum. Odontomachus affinis has transverse striae that might form concentric transverse ellipses on the pronotum and O. panamensis the striae form angles anteriorly.

Males are similar to those of O. chelifer , but they can be distinguished by the body color, which is yellowish brown in O. affinis and light brown to dark brown in O. chelifer .Also, in males of O. affinis the striae are limited to the anterior and lateral mesoscutal margins, while males of O. chelifer have the mesoscutum completely longitudinally striate.

The main variations are in the pattern of striae on the pronotum and mesonotum, and the body size. Specimens from the same series show pronotal striae completely transverse or forming concentric transverse ellipses. Mesonotal striae rarely form obtuse angles anteriorly or may be completely longitudinal. The ocelli can be large and completely surpassing the posterior cephalic margin, in frontal view, or smaller and partially surpassing the posterior margin. In the former, the posterior margin between the lateral ocelli is deeply concave and reaches the median ocellus.

There is no mention regarding how many specimens Pinel sent to Guérin-Méneville in the original description, but according to the ZSM website, there is a type specimen considered as the holotype (SNSB, 2023). However, no holotype or lectotype was designated in the original publication, which renders this ‘type’ specimen automatically as a syntype (Article 73.2.). Specimens GBIF-D/FoCol 1055 1☿, GBIF-D/FoCol 1056 1☿, GBIF-D/FoCol 1057 1♀, GBIF-D and FoCol 1058 1♂ [MNHN] were collected in Brazil by Roger and are labeled as type specimens. There is no mention of gynes or males in the original description and Roger describes the gyne years later ( Roger, 1861). The handwriting on these labels is different from the FoCol 0682 syntype labels [ZSM], suggesting they are not from the same series. Therefore, these specimens collected by Roger are not considered type specimens, however, based on the handwriting, they can be considered from the same series of the gyne description publication ( Roger, 1861). The syntype FoCol 0682 [ZSM] examined is without the head and has the petiolar node considerably damaged. Furthermore, it is pinned through the pronotum which is separated from the mesonotum. Due to these conditions, it was not measured.

According to Fernandes et al. (2021), O. affinis is the sister species of O. chelifer , and both share transverse striae on the anterior male mesoscutum and the oblique to longitudinal striae that converge posteriorly on the dorsal face.

A single specimen labelled as coming from Acre was examined but no other specimens from the Amazon were found. It was considered a labelling mistake, since we found in the same lot, specimens of O. chicomendesi sp. nov., which has a strict Amazonian distribution and that were labeled as coming from Santa Catarina. Probably the labels were misplaced thus explaining both unexpected records.

Material examined: 86☿, 7♀ and 11♂. BRAZIL: Bahia: Iguaí (3☿ and 3♀) . Espírito Santo: Santa Teresa (2☿) ; REBIO Augusto Ruschi (6☿); [no further data] (1☿) . Paraná: Antonina (11☿, 3♂) ; Morretes (4♂) ; São José dos Pinhais (3☿) . Rio de Janeiro: Angra dos Reis (1☿) ; Niterói (1☿) ; Petrópolis (2☿) ; Rio de Janeiro (3☿, 2♀, 1♂) . Santa Catarina: Florianópolis (2☿) ; P. E. da Serra Furada (3☿); Pomerode (7☿) ; Siderópolis (4☿) ; Timbé do Sul (2☿) . São Paulo: Mogi das Cruzes (23☿) ; Parque das Neblinas (1☿) ; São Paulo (10☿, 2♀, 3♂) ; São Sebastião (1☿) .

Odontomachus allolabis Kempf, 1974 ( Figures 13-A , 28-A , 51 , 52 , 53 and 54 )

Figures

FIGURE 4. Morphological measurements of Odontomachus. A, cephalic frontal view of worker; mesosoma of worker B, in lateral view and C in dorsal view; D, mesosoma of male in lateral view; E, cephalic frontal view of male; F, forewing in dorsal view. Dash lines representing the measurements. Abbreviations: EL (Eye Length); FL (Hind Femur Length); FWL (Forewing Length); GL (Gaster Length); HL (Head Length); HOW (Head Ocular Width); HVW (Head Vertexal Width); HW (Head Width); IOW (Intra Ocellar Width); ML (Mandible Length); SL (Scape length); OES (Ocellar Eye Space); OW (Ocellar Width); PnW (Pronotum Width); PtH (Petiole Height); PtL (Petiole Length); PtW (Petiole Width); TL (Total Length); WL (Weber’s Length).

FIGURE 6. Variation of worker morphology of Odontomachus. In cephalic frontal view A, O. hastatus, mandibles elongated, vertex trapezoidal and long; B, O. chelifer mandibles short, vertex rectangular and short; C, O. bauri mandibles short and vertex trapezoidal. Pronotum in lateral view D, O. hastatus, triangular; E, O. biumbonatus angular; F, O. bauri, rounded. Petiole in lateral view G, O. hastatus, pedunculate and anteriorly elongated; H, O. chelifer sessile and angular; I, O. biumbonatus sessile and cylindrical; J, O. bauri sessile and conical. Gaster in lateral view K, O. hastatus, anterior and dorsal margins continuous forming a single convexity; L, O. chelifer and M, O. bauri, anterior margin straight forming blunt angle with dorsal convex margin. Dash lines and gray area representing shape of each structure. Scale bar = 1mm.

FIGURE 7. Variation of gyne morphology of Odontomachus. Pronotum and mesoscutum in lateral view (left) and dorsal view (right), forewing in dorsal view.A, O. hastatus, pronotum longer than high with dorsal margin straight, cervical area continuous to the pronotum, mesoscutum with short, almost vertical anterior margin that sharply curves onto horizontal dorsal margin; B, O. chelifer, pronotum dorsal margin straight, mesoscutum anteriorly convex curving onto dorsal margin; C, O. xeta sp. nov., pronotum dorsal margin slightly concave with angular aspect, mesoscutum broadly convex; D, O. bauri, pronotum dorsal margin convex, mesoscutum broadly convex. B, C and D pronotum in lateral view higher than long, in dorsal view constricted anteriorly forming neck. Dash lines representing shape of each structure. Scale bar = 1 mm. Wings out of scale.

FIGURE 8. Petiole of workers in lateral view. A, pedunculate (O. hastatus); B, sessile (O. affinis). Dash lines highlighting anterior portion of petioles.

FIGURE 9. Vertexes of Odontomachus workers in frontal view. A, smooth and shining, nuchal collar present (O. hastatus); B, striate, nuchal collar present (O. davidsoni); C, smooth and shining, nuchal collar absent (O. mormo). Dash lines highlighting occipital carina.

FIGURE 10. Pronotum of Odontomachus workers in dorsal view. A, central disk smooth and shining (O. hastatus); B, central disk with conspicuous striae (O. davidsoni). Arrows pointing to the central portion of pronotum.

FIGURE 11. Ocular prominences of Odontomachus workers in frontal view. A, acute and projecting anteriorly (O. cornutus). Source: MZSP, imaged by: Mônica Ulysséa; B, rounded and not projecting anteriorly (O. mormo). Dash lines highlighting ocular prominence shapes.

FIGURE 12. Heads of Odontomachus workers in cephalic frontal view.A, reduced eyes, scape not reaching the posterior head margin (O. spissus); B, not reduced eyes, scape surpassing the posterior head margin (O. affinis). Dash lines highlighting scape lengths and arrows pointing to the eyes.

FIGURE 13. Petiolar nodes of Odontomachus workers in lateral view. A, node with posterior margin rounded and projecting laterally, dorsal portion of anterior face convex (O. allolabis); imaged by: Adrian Troya. B, node with posterior margin at most slightly convex but never projecting laterally; dorsal portion of anterior face straight to slightly concave (O. panamensis). Dash lines highlighting the shape of the dorsal portion of anterior face of petiole node.

FIGURE 14. Anterior portion of mesosoma of Odontomachus workers in dorsal view. A, central disc of pronotum with curved transverse striae, Mesopleuron without anteroventral rounded lobe (O. affinis); B, central disc of pronotum with striae forming angles anteriorly, Mesopleuron with anteroventral rounded lobe (O. panamensis). White squares with lines representing the striation pattern of pronotum and dash lines highlighting the anterior projection of mesopleuron.

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 17. First gaster tergum sculpturing of Odontomachus workers in dorsal view. A, anteriorly punctate and gradually becoming longitudinally striate posteriorly (O. scalptus); B, smooth and shining (O. yucatecus).

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 20. Pronotum of Odontomachus workers in lateral view. A, posterior portion of ventral margin of pronotum in lateral view with anteriorly curved long hairs, almost as long as the anterior procoxal hairs and propleuron with long erect hairs (O.laticeps); B, posterior portion of ventral margin of pronotum in lateral view without long hairs, propleuron with short decumbent hairs (O. bauri). Vertical arrows indicating the hairs on propleuron and horizontal arrows indicating the hairs on ventral portion of pronotum.

FIGURE 21. Petiolar node shapes of Odontomachus workers in lateral view. A, node cylindrical (O. xeta sp. nov.); B, node conical (O. haematodus). Dash lines highlighting anterior and posterior face shapes.

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 24. Body color pattern of Odontomachus workers in lateral view. A, head ferruginous, strongly contrasting with the dark brown body (O. erythrocephalus); B, head and body dark brown almost black (O. bauri).

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 26. Metaesternal process of Odontomachus workers in ventral view, middle coxae on superior portion and hind coxae on inferior portion. A, metasternal process forming pair of spines (O. haematodus); B, metaesternal process not forming pair of spines of (O. bauri). Dash lines highlighting the metasternal process shapes.

FIGURE 27. Propleuron of Odontomachus workers in ventral view. A, propleuron with fine transverse striae (O. cupreus sp. nov.); B, propleuron smooth and shining with coarse lateral striae (O. ruginodis).

FIGURE 28. Mesoscutum sculpturing of Odontomachus gynes in dorsal view.A, mesoscutum smooth and shining (O. allolabis, imaged by: Adrian Troya); B, mesoscutum with longitudinal striae (O. affinis).

FIGURE 29.Mesosoma of Odontomachus gynesin lateral view.A, pronotumstriae regular, propleuronwithout hairs and mesopleuron without anteroventral rounded lobe (O. affinis); B, pronotumstriae irregular,propleuron with hairs and mesopleuron with anteroventral rounded lobe (O. panamensis). Arrows pointing to the propleuron. 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 31. Propleuron of Odontomachus gynes in ventral view. A, propleuron with conspicuous striae (O. scalptus); B, propleuron smooth and shining with lateral striae restricted anteriorly of (O. haematodus).

FIGURE 32. Pronotum of Odontomachus gynes in lateral view. A, dorsal face anteriorly concave forming obtuse angle posteriorly (O. xeta sp. nov.); B, anteriorly straight becoming convex posteriorly (O. cupreus sp. nov.). Dash lines highlighting the pronotum shapes.

FIGURE 33. Pronotal striae of Odontomachus gynes in dorsal view. A, dorsum with striae strongly curved (O. scalptus); B, dorsum with striae dorsum with striae weakly curved (O. meinerti). White squares with lines representing the striation pattern of pronotum in dorsal view.

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 35. Axillae sculpturing of Odontomachus gynes in dorsal view. A, axilla with longitudinal striae (O. meinerti); B, axilla smooth and shining (O. haematodus). Arrows pointing to the axillae.

FIGURE 36. Petiolar nodes of Odontomachus gynes in lateral view. A, node smooth and shining (O. insularis); B, node with coarse striae (O. bauri).

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 40. Propodeum of Odontomachus males in posterior view. A, dorsal and posterior face separated by coarse striae, without concentrical striae (O. affinis); B, dorsal and posterior face not separated by coarse striae, with concentrical striae (O. laticeps). Arrows pointing to the propodeum striae patterns.

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 42. Mesoscutellum of Odontomachus males in dorsal view. A, mesoscutellum with longitudinal carina (O. caelatus); B, mesoscutellum without longitudinal carina (O. biumbonatus). Arrows pointing to the mesoscutella.

FIGURE 43. Propodeum and posterior face of petiole node of Odontomachus males.A, propodeum coarsely rugose and petiole node with apex acute and ascending striae (O. erythrocephalus); B, Propodeum with striae forming concentrical longitudinal arcs and transversal striae on lateral portion, petiole node with blunt apex without ascending striae (O. meinerti). Arrows pointing to the petiole node sculpturing and dash lines highlighting the petiole node apex shapes.

FIGURE 44. Mesoscutum sculpturing of Odontomachus males in dorsal view.A, with conspicuous oblique and irregular striae and posterior portion with coarse longitudinal striae (O. erythrocephalus); B, central portion with effaced striae and posterior portion without coarse longitudinal striae (O. insularis). Arrows pointing to the posterior portion of the mesoscuta.

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 46. Metasternal process of Odontomachus males in ventral view.A, forming a pair of spines (O. haematodus); B, with pair of lateral cuticle borders (O. bauri). Dash lines highlighting the metasternal process shapes.

FIGURE 47. Mesoscutum color pattern of Odontomachus males. A, with dark-brown spots (O. bauri); B, without dark-brown spots (O. ruginodis, CASENT0104177, imaged by: April Nobile, Source: AntWeb.org.

FIGURE 48. Odontomachus affinis 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 49. Odontomachus affinis gyne. A, head in frontal view; B, mesosoma in dorsal view; C, full lateral view.

FIGURE 50. Odontomachus affinis male. A, head in frontal view; B, mesosoma in dorsal view; C, propodeum in posterior view; D, full lateral view.

FIGURE 51. Map of distribution of O. affinis, O. allolabis and O. panamensis. Triangles representing the type-localities.

FIGURE 52. Odontomachus allolabis worker.A, head in frontal view; B, mesosoma in dorsal view; C, metasternum in ventral view with middle coxae at superior portion and hind coxae at inferior portion; D, mesosoma in lateral view; E, petiole in lateral view; F, gaster in dorsal view. Imaged by: Adrian Troya.

FIGURE 53. Odontomachus allolabis holotype.A, head in frontal view; B, full dorsal view; C, full lateral view.Arrow pointing to the ventral gaster opening. Source: MZSP, imaged by: Mônica Ulysséa.

FIGURE 54. Odontomachus allolabis gyne. A, head in frontal view; B, dorsal view; C, full lateral view; D, petiole in lateral view; E, metasternum in ventral view with middle coxae at superior portion and hind coxae at inferior portion. Imaged by: Adrian Troya.