Ergatoid Queens of Slave-making Ant Polyergus samurai YANO (Hymenoptera, Formicidae)

Ergatoid queens of Polyergus samurai YANO, 1911, are firstly described. This caste is easily distinguishable from the normal queens by the workerlike trunk, and from the workers by the large head and gaster, convex mesonotum, and developed ovaries. The developed reproductive organs suggest that the ergatoid queens can produce female offsprings. The ground activities of the caste were also observed in the field.