While the idea that not only pollinators, but also enemies (herbivores/pathogens), can contribute to plant floral evolution is gaining acceptance, the role predation plays in plant breeding system evolution is currently unknown. Yet there is ample evidence that plants with separate sexes represent a dimorphic resource base for herbivores. Herbivores preferentially feed on plants with male function relative to those lacking male function (i.e., female plants) suggesting that herbivores may select host plants based on pollen production and, more specifically, may be attracted to pollen scent. This hypothesis will be tested by characterizing floral, pollen, and vegetative scents of female and hermaphrodite wild strawberry and by determining if weevils are attracted to scents specific to the pollen-bearing sexual morph. These data will evaluate a mechanism for sex-biased selection of host plants by weevils and thus will be instrumental in the development of hypotheses concerning the role of herbivory in breeding system evolution. Moreover, by elucidating the role of floral scent in attracting herbivores this research may suggest an alternative to the use of pesticides for controlling herbivory.
