Odontomachus yucatecus Brown, 1976

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 : 154-155

Odontomachus yucatecus Brown, 1976 ( Figures 17-B , 71 and 118 )

Odontomachus yucatecus Brown, 1976: 169 (☿).

Type specimens: Holotype. MEXICO: Campeche, 10km. e. [East] Campeche, VII-28. 29-53[28-29.vii.1953], E. O. Wilson [col.], #132 Strays, MCZ Holotype 34797 1☿ [ MCZ] .

Paratype. Same locality of Holotype. MEX [ ICO]: 10 km E[ast] of Campeche vii.28-29.53 [28-29.vii.1953], E. O. Wilson col., #132 [strays], MZSP77727 1☿ [ MZSUP] .

Paratype [Images]. GUATEMALA: Esquintla , Dec. 30. 1911 [30.xii.1911], Wm. M. Wheeler col., BMNH (E) 1014006, ANTWEB CASENT 0900609 1☿ [ BMNH] .

Etymology: Probably alludes to the Yucatán native people who lives in the Yucatán peninsula, Mexico, which is the type-locality of this species.

Diagnosis: (☿) Propleuron with fine regular transverse striae. Mesonotum with regular longitudinal striae. Gastral terga slightly imbricate, almost smooth and shining. (♀) Unknown. (♂) Unknown.

Worker

Holotype measurements: EL 0.30, HL 1.82, HoW 1.32, HvW 1.17, HW 1.28, ML 0.93, SL 1.55, PnW 0.79, WL 2.85, FL 1.71, FL 1.71, PTH 1.05, PTL 0.51, PtW 0.32, GL 2.67, TL 8.78. CI 0.70, MI 0.51, PtI 2.05, SI 0.85, VI 0.91.

Non-type measurements: EL 0.4, HL 2.6-2.7, HoW 2.1, HvW 1.7-1.8, HW 1.9-2.0, ML 1.4-1.5, SL 2.2-2.4, PnW 1.2, WL 3.2-2.8, FL 2.4-2.5, PTH 1.1, PTL 0.5-0.6, PTW 0.5, GL 3.0-3.3, TL 10.6-11.0. CI 0.70-0.76, MI 0.53-0.55, PtI 1.83-2.20, SI 0.84-0.88, VI 0.89-0.90 (n= 2).

Head. Vertex trapezoidal, wider than long in frontal view; with regular longitudinal striae diverging and effacing posteriorly, reaching posterior margin. 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 wounded. Clypeus with fine regular longitudinal striae on median portion. Malar area with fine inconspicuous transverse striae 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 surpassing occipital corner about pedicel half-length or less.

Mesosoma. Pronotum in lateral view rounded, dorsal margin slightly convex; neck well developed anteriorly in dorsal view; lateral margin rounded; central disc of pronotum with regular longitudinal striae, lateral striae forming concentric arcs directed anteriorly. Propleuron with transverse striae effaced on central portion. Mesonotum wider than long; with regular longitudinal striae. Mesopleuron with vestigial carina on anteroventral portion not forming projection; mostly smooth and shining, anterior portion with regular transverse striae. Mesometanotal sulcus vestigial, mesonotum continuous to metanotum; with regular longitudinal striae as mesonotum. Metanotum vestigial. Metapleural gland bulla with fine transverse striae. Propodeum in lateral view straight; posterior margin length about 1/3 of dorsal length. Metasternum with metasternal process open, cuticle border bilobate separated on middle line by longitudinal sulcus; regular transverse coarse striae.

Petiole. Sessile. Conical node, anterior margin in lateral view usually continuous with petiolar spine. Spine robust, straight or slightly curved posteriorly. Coarse regular transverse striae covering all surface. Subpetiolar process wider than long keel-shaped; tip blunt to slightly acute; posterior portion not 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 slightly imbricate to smooth and shining.

Color and size. Body dark brown almost black. Legs and antennae brown to yellowish. Medium ants.

Pilosity. Hook-shaped, scattered, conspicuous and short pubescence spread over the body, separated each other about their length. Pubescence on petiole limited to anterior face extending to lateral faces. Short hairs on anterior portion of procoxa and Propleuron smaller than coxae width. Pronotum with three or four pairs of long, curved erect hairs longer than maximum procoxa width. Short subdecumbent hairs on posterior 2/3 of gastral terga directed posteriorly, as long as pronotum hairs.

Natural history: The biology of this species is poorly known. The type-series specimens were collected near a cave opening in Yucatán, Mexico, in areas of degraded evergreen forest, and second growth Cecropia sp. , in the Yucatán Peninsula and lowlands of Veracruz in Mexico ( Brown, 1976). Odontomachus yucatecus can be collected with Berlese funnel ( Brown, 1976) and pitfalls (label data) and has a wide distribution from Mexico to northeast South America on Ecuador ( Fig. 71 ).

Comments: Odontomachus yucatecus can be confused with O. scalptus due to the almost straight longitudinal striae on the lateral portions of mesonotum. But it can be quickly recognized by the gaster sculpturing: weakly imbricate to almost smooth and shining while O. scalptus has the gastral terga striate-punctate or completely punctate. Another species that might be misidentified as O. yucatecus is O. bauri , due to the shape and sculpturing of the petiolar node in both, conical and coarse striate. The longitudinal striation on the mesonotum of O. yucatecus is enough to separate it from O. bauri , which has transverse striae in the mesonotum.

Material examined: (15☿). ECUADOR: Morona-Santiago: Los Tayos (8☿) . Napo: Ahuano (2☿) . Sucumbíos: Parque Nacional Yasuní (3☿) . MEXICO: Chiapas: 10 km S Palenque (1☿) ; Playón La Gloria (1☿) .

Figures

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

FIGURE 118. Odontomachus yucatecus 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.