Sight in a Clique, Scent in Society: Plasticity in the Use of Nestmate Recognition Cues Along Colony Development in the Social Wasp Polistes dominula

This review covers selected literature from 1982 to the present on some of the ecological, behavioral, and biochemical aspects of hydrocarbon use by insects and other arthropods. Major ecological and behavioral topics are species- and gender-recognition, nestmate recognition, task-specific cues, dominance and fertility cues, chemical mimicry, and primer pheromones. Major biochemical topics include chain length regulation, mechanism of hydrocarbon formation, timing of hydrocarbon synthesis and transport, and biosynthesis of volatile hydrocarbon pheromones of Lepidoptera and Coleoptera. In addition, a section is devoted to future research needs in this rapidly growing area of science.

The traditional emphasis when measuring performance in animal cognition has been overwhelmingly on accuracy, independent of decision time. However, more recently, it has become clear that tradeoffs exist between decision speed and accuracy in many ecologically relevant tasks, for example, prey and predator detection and identification; pollinators choosing between flower species; and spatial exploration strategies. Obtaining high-quality information often increases sampling time, especially under noisy conditions. Here we discuss the mechanisms generating such speed-accuracy tradeoffs, their implications for animal decision making (including signalling, communication and mate choice) and the significance of differences in decision strategies among species, populations and individuals. The ecological relevance of such tradeoffs can be better understood by considering the neuronal mechanisms underlying decision-making processes.

Organisms use signals of quality to communicate information about aspects of their relative phenotypic and genetic constitution. Badges of status are a subset of signals of quality that reveal information about an individual's size and dominance. In general, signals of quality require high and differential costs to remain honest (that is, prevent low-quality cheaters from exploiting any fitness benefits associated with communicating high quality). The theoretically required costs for badges of status remain controversial because the development (or 'production') of such signals often seems to be relatively cost-free. One important hypothesis is that such signals impose social (or 'maintenance') costs incurred through repeated agonistic interactions with other individuals. However, convincing empirical evidence for social costs remains elusive. Here we report social costs in a previously undescribed badge of status: the highly variable black facial patterns of female paper wasps, Polistes dominulus. Facial patterns strongly predict body size and social dominance. Moreover, in staged contests between pairs of unfamiliar wasps, subordinate wasps with experimentally altered facial features ('cheaters') received considerably more aggression from the dominant than did sham controls, indicating that facial patterns are signals and that dishonest signalling imposes social costs.