Strongylognathus koreanus

Japanese Name

Ibari-ari

Pisarski, B. (1966) Etudes sur les fourmis du genre Strongylognathus Mayr. Annales Zoologici 23: 509-523.

Total length of workers around 3 mm. Body yellowish brown. Head approximately square, 1.1 times as long as wide; posterior margin almost straight, very weakly convex medially in full face view. Anterior margin of clypeus broadly convex. Antennal scapes short, 0.7 times as long as head length. Mesonotal dorsum almost straight in profile; dorsum of propodeum gently convex. Posterodorsal corner of propodeum with a pair of obtuse spines. Petiole triangular, with a short peduncle. Subpetiolar process low, anteroventrally angled. Viewed from above the postpetiole 1.45 times as wide as long and wider than the petiole. Front of head and areas surrounding the eyes with longitudinal rugae; head elsewhere smooth and shining. Dorsa of head, mesosoma, petiole, postpetiole, and gaster with scattered stout hairs. Female around 7 mm long; color brown; mandibles remarkably sickle-shaped, as in the workers.

This species is very rare. It has been collected only twice in Japan, from Masutomi-onsen, Yamanashi Prefecture (Nakano,1938), and Washu-zan, Okayama (not Hiroshima) Prefecture (Collingwood, 1976). Both were taken from nests of Tetramorium tsushimae. This species has long been known but nomenclaturally undetermined in Japan. Terayama (1988) recently identified it as S. koreanus Pisarski, originally described from the Korean Peninsula. There are only two Korean collection records, from Myohyang (the type locality) and Gumpongli-Saryangdo (Kim et al., 1989).

Honshu (Masutomi, Yamanashi Pref.; Washu-zan, Hiroshima Pref.); Korean Peninsula.