Myrmica jessensis

Japanese Name

Ezo-kushike-ari

Forel, A. (1901) VariŽtŽs myrmŽcologiques. Annales de la SociŽtŽ Entomologique de Belgique 45: 334-382.

Myrmica lobicornis jessensis Forel, 1901, Myrmica yessensis [!] Collingwood, 1976, Myrmica lobicornis subsp. littoralis Weber 1948a,

Total length of workers around 3 - 4.5 mm. Body color brown to reddish brown, head and gaster relatively dark. Antennal scape bent at the base; the angle of the dorsal margin of the bend about 100 degrees, viewed parallel to the flexing face of the funiculus. Dorsum of the bend margined at a right angle to the axis, and usually with a thin projecting blackish brown lamella. Antennal scape slender near the base. Anterior margin of clypeus concave in the middle. Rugae on the dorsa of head and mesosoma rather weakly impressed,the intervening spaces narrow. Metanotal groove variable, shallow to deep. Propodeal spines rather short. Petiolar node short, posterodorsal border not angular.

This species nests under stones or in the soil of open grasslands or bare lands, and can be abundant in dry riverbeds. It ranges from 200 to 1700 m above sea level in central Honshu (Morisita,1945), and has been found at 20 m elevation in the dry bed of the Sagami River, Kanagawa Prefecture (Kubota, 1983).

Hokkaido, Honshu (the central part and northwards); Sakhalin, Kunashiri I.