On the ants (Hymenoptera: Formicidae) of the Philippine Islands: V. The genus Odontomachus Latreille, 1804. Sorger, D. M. Zettel, H. Myrmecological News 2011 14 141 163 48QCG 255797 Insecta Formicidae Odontomachus Animalia Hymenoptera Arthropoda species rixosus  Diagnosis: Palp formula: 4, 4. Subapical teeth of mandibles short and truncate ( O. latidens, O. monticola) or only slightly truncate and long ( O. rixosus). Posterior portion of head tends to be fairly broad. Petiolar node tending to height reduction. Diversity and distribution: Brown (1976) includes three species: Odontomachus latidens Mayr, 1867, O. monticola Emery, 1892, and O. rixosus Smith, 1857. The group comprises those Oriental species with truncate subapical teeth of the mandibles, except O. simillimus, which belongs to the O. haematodusgroup (with palp formula 4, 3). Odontomachus monticolais distributed from northeastern India to southern China and Vietnam; O. latidensfrom Peninsular Malaysia to Borneo, Sumatra and Java; and O. rixosusfrom southeast Asia to Java, Borneo, and the southern Philippines (Brown 1976, and this study). Odontomachus monticolais strongly varying (see Brown 1976: pp. 157-159), but some of its synonyms are probably valid species.  In its present concept, the O. rixosusgroup is almost complementary biogeographically to the O. infandusgroup, with one exception: an overlap on the island of Mindanao.