Lateral Vibrations by Social Wasps Signal Larvae to Withhold Salivary Secretions ( Polistes fuscatus , Hymenoptera: Vespidae)

Abstract

The communicative meaning of an oscillation (lateral vibration) performed by foundresses of social wasps (Polistes fuscatus) was investigated by sampling larval saliva from 12 postworker, single-foundress colonies and by viewing videotapes of 17 multiple-foundress (139.3 h) and 16 single-foundress (32 h) preworker colonies. Foundresses spent significantly more time inspecting cells before performing a lateral vibration (LV) than after and commonly became inactive after performing an LV. The proportion of departures temporally proximate to LVs was significantly greater in single- than in multiple-foundress colonies. Departures and LVs were significantly temporally associated in single-foundress colonies. Single foundresses were significantly more likely to perform an LV prior to departing on longer than shorter trips. In multiple-foundress colonies there was a significant temporal relationship between LVs and departures that left the nest unattended. Larvae secreted significantly less saliva, a nutritious substance provided to adults, immediately after an LV than in the absence of an LV. Contextual evidence and results of sampling larval saliva indicate that LVs by foundresses signal larvae to withhold or reduce their secretion of saliva.