ABDOMINAL VIBRATIONS IN A PRIMITIVELY EUSOCIAL WASP BELONOGASTER JUNCEA JUNCEA (VESPIDAE, POLISTINAE)

Abdominal oscillations such as those described in several polistine wa sps are described in Belonogaster juncea juncea. A field study conduct ed at both pre- and post-emergence stages enabled us to distinguish tw o types of abdominal movements namely ''longitudinal vibrations'' and ''abdominal wagging''. All females of the nest can perform ''longitudi nal vibrations''. This behavior stimulates larvae to produce salivary secretions. The adults, head positioned in a cell containing a larva, perform dorso-ventral movements of the abdomen with the body held in a rigid position. ''Abdominal wagging'', described for the first time i n the genus Belonogaster, is the dorso-ventral movement of the abdomen when the wasp is either stationary at the top of the nest or while wa lking over cells. This hard vibration can bring about the vibration of the entire body. By recording for each individual the frequency of '' abdominal wagging'', we show that this behavior, implicated in the dom inance interactions between adults, is performed only by dominant fema les in post-emergence colonies and rarely by subordinates in pre-emerg ence colonies. As a consequence, abdominal wagging is a good means of identifying the dominant female.