NSF proposal # IBN-9407162, Mechanisms of indirect sexual selection in an ultrasonic pyralid moth; Co-PIs Michael D. Greenfield and Robert D. Collins. Non-technical summary In many animals the basic processes of sexual selection include male male competition and female choice. It is generally believed that female choice can involve preferences for mates who provide direct benefits such as care of offspring and preferences for mates who provide indirect benefits via the genes that they contribute toward the offspring. Recently, theoretical biologists have confirmed that several different models of indirect sexual selection are plausible. However, experimental evidence for, and distinctions between, these models are meager. This paucity largely exists because many of the species in which sexual selection is studied are not amenable to the controlled experiments needed to test assumptions underlying the various models. In the current project we will overcome these previous difficulties by studying female choice in an unusual pyralid moth, Achroia grisella, that can be observed and raised in the laboratory. Female choice in A. grisella occurs via an indirect mechanism - selection based on male ultrasonic signals. We will employ a variety of breeding experiments to study the heritabilities of male signaling characteristics and of female preferences for these characteristics. The general viability of offspring of females who mate with preferred males will also be noted. Our findings will provide assessments of the alternative hypotheses (1) that indirect female choice is arbitrarily based on genetic attributes which are unrelated to general viability and (2) that the genetic attributes chosen are related to mate and offspring viability. Study of A. grisella will also increase our fundamental understanding of ultrasonic signaling and perception, and it may lead to improved control strategies of this (and related) species, a pest of honeybee colonies.
