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Odontomachus

Odontomachus

Odontomachus are large ponerinae ants which are immediately recognised by the characteristic shape of the head and mandibles. They are most likely to be confused with species of Anochetus but differ in having the nuchal carina, which separates the dorsal from the posterior surfaces of the head, converging into a V at the midline. In the closely related Anochetus, the nuchal carina forms a broad, uninterrupted curve across the posterior dorsal extremity of the head.
They are generalist predators on small invertebrates, hunting singly and capturing prey with their elongate trap-like jaws. Patek et al. (2006) investigated the biomechanics of mandible strikes in O. bauri, which are used to capture prey, eject intruders, or jump to safety. Don´t miss the videos! More on the biology of Odontomachus can be found in the revision of Brown (1976).

Odontomachus affinis Guérin-Méneville 1844

on Hymenoptera Name Server

Identification:
Vertex smooth & shining; antennal scapes surpass posterior border of head in full face view; color redish-brown.

Taxonomic Notes:
Males of Odontomachus are rarely collected and not easily matched with workers. During the FoCol project a male O. affinis from a type series deposited at the Museum für Naturkunde Berlin has been documented. Christiana Klingenberg kindly provided the image of this specimen: Male of O. affinis. Note the petiolar node of the male im comparison to the worker node.


Natural History:
Regarding this species, Brown (1976) states: "O. affinis is restricted to wet subtropical forests of SE Brazil (Espiritio Santo to Santa Catarina). In Sao Paulo state, at least, it occurs in and under rotten logs in plateau forest; I did not find it in the warmer lowland forest along the coast."
I have collected this species from leaf litter samples collected in the lowland forests of Cachoeira Nature reserve, though this species seems to be rare.

Odontomachus affinis - head view Odontomachus affinis - head view

Odontomachus chelifer (Latreille 1802)

on Hymenoptera Name Server

Identification:
Large species (largest Odontomachus in the New World); dorsal surface of head striate; first and second gastral tergite transversely striate.

Natural History:
A common species in the reserve.

Odontomachus chelifer - head view Odontomachus chelifer - lateral view

Odontomachus haematodus (L. 1758)

on Hymenoptera Name Server

Identifcation:
Paired, slender, acute sternal spines produce from the transverse ridge just in front of the metacoxae; body brown, legs of lighter color.

Odontomachus haematodus - head view Odontomachus haematodus - lateral view

Odontomachus meinerti (Forel 1905)

on Hymenoptera Name Server

Identification:
Disc of first gastric tergite very densely punctulate, opaque, longitudinally striae over a posterior portion of variable extent ; small species, light to dark brown in color.

Natural History:
A common species at Cachoeira Nature reserve. I have collected 17 specimens from a single soil sample. Therefore this Odontomachus, at least occasionally, seems to nest in soil.

Odontomachus meinert - head view Odontomachus meinert - lateral view

Offline References for Odontomachus

Brown, W. L. (1976): Contributions toward a reclassification of the Formicidae. Part VI. Ponerinae, tribe Ponerini, subtribe Odontomachiti. Section A. Introduction, subtribal characters. Genus Odontomachus. Studia Entomologica 19:67-171.

Patek, S.N. , Baio, J.E. , Fisher, B.L. , and A. V. Suarez (2006): Multifunctionality and mechanical origins: Ballistic jaw propulsion in trap-jaw ants. PNAS 103(34): 12787-12792.

Date of this version: 27.03.2007

This work is licensed under a Creative Commons License
page author: Jochen H. Bihn
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