Oligomyrmex yamatonis

Japanese Name

Kotsuno-ari

Terayama, M. (1996) Taxonomic studies of the Japanese Formicidae, part 2. Seven genera of Ponerinae, Cerapachyinae and Myrmicinae. Nature and Human Activities, 1, 9-32.

Oligomyrmex sauteri Forel (Azuma, 1951; not O. sauteri)

Total length around 2 mm in soldiers, around 1 mm in workers. Body color light reddish brown, heads of soldiers blackish. In soldiers: head 1.3 times as long as wide, with parallel sides in frontal view; vertex with a pair of tubercles, posterior margin of head strongly concave; mandibles each with 5 teeth; antennae 9-segmented; eyes small, with 2 or 3 facets, situated on the anterior portion of the head capsule; pronotal and mesonotal dorsa raised in profile; mesopleuron simple, not divided by an oblique furrow; posterolateral margins of propodeum with a thin lamellate flange below the propodeal tooth; subpetiolar process small, forming a blunt triangle; head, mesosoma, petiole and postpetiole covered with punctures; head with many longitudinal rugae. In workers: Head slightly longer than wide in frontal view; mandibles each with 5 teeth; eyes each with only one facet, situated at midlength of head capsule in side view; thin lamellar flanges on posterolateral margins of propodeum; subpetiolar process obscure; head, mesosoma, petiole and postpetiole covered with small, coarse punctures.

This species was first recorded from Japan by Azuma (1951). Thereafter Japanese myrmecologists have consistently used the name O. sauteri for this relatively common ant. However, O. sauteri was originally described from Taiwan, and morphological comparison between Japanese and Taiwanese specimens suggests that they represent separate species.

Honshu, Shikoku, Kyushu, Yaku I., Nansei Is.