Polyethism in an Oriental Hornet (Vespa orientalis) Colony

The present study describes the daily activities of the Oriental hornet (Vespa orientalis) workers older than 48 hours as observed in an Artificial Breeding Box (ABB) in our laboratory at the peak of the active season. These workers were picked randomly from a population of a single nest that was enabled to free egress into the field. The study points to the existence of polyethism in the nest of V. orientalis with the adult worker hornets, separating them into three groups in accordance with the frequency and nature of their exits from the nest, and the tasks which they perform. This polyethism was not age-dependent. Recordings were made of the following vespine activities: the frequency of exits to the field during various hours of the day and the various roles undertaken by the hornets. Also investigated was the assignment of tasks among the hornets and the preference given to some tasks over others. The general organization of traffic and other movements in the colony is discussed.