Odontomachus rixosus species group

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. haematodus group (with palp formula 4, 3). Odontomachus monticola is distributed from northeastern India to southern China and Vietnam; O. latidens from Peninsular Malaysia to Borneo, Sumatra and Java; and O. rixosus from southeast Asia to Java, Borneo, and the southern Philippines (Brown 1976, and this study). Odontomachus monticola is strongly varying (see Brown 1976: pp. 157-159), but some of its synonyms are probably valid species.

In its present concept, the O. rixosus group is almost complementary biogeographically to the O. infandus group, with one exception: an overlap on the island of Mindanao.