Abstract IBN 96-23764 Hoy, Crocroft & Gilbert Offspring-Parent Communication Within all animal societies, most of an individual s social interactions are carried out by means of communication. Yet the role of communication in social behavior remains controversial, in part because it has been difficult to integrate information about the adaptive significance of signaling for both senders and receivers within the same system. In the subsocial treehopper, Umbonia crassicornis, communication between parents and offspring plays a critical role in their response to predation. Females produce only a single clutch of young, and thus there is a high overlap of interests between parent and offspring about the extent of parental investment in offspring defense. The fitness costs and benefits of signaling are therefore shared by both senders and receivers. This study will address the benefits of signaling by quantifying the effectiveness of the parents anti-predatory response, that is evoked by nymphal signals. The costs of signaling will be addressed by manipulating female investment in offspring defense, to determine whether current benefits accrued by evoking parental defense are offset by a reduction in parental survivorship and potential for future defense. The proposed research should be of general interest within the fields of animal communication and social evolution.
