XVI International Botanical Congess

Mechanisms of tolerance of insect damage are poorly understood. However, characters associated with developmental phenology may contribute to tolerance. Using Helianthus annuus (wild sunflower) as a model system I am examining the hypothesis that tolerance of damage by Haplorhynchites anaeus, the head-clipping weevil, is correlated with either flowering phenology or patterns of meristem commitment. Haplorhynchites clips entire inflorescences just as the first florets produce pollen, well before seeds have begun to fill. Thus, resources that would have been used to fill seeds may be redirected to other meristems. In fact, plants that have had inflorescences clipped do commit additional meristems to inflorescences later in the season. I will discuss the effect that variation in developmental phenology has on the ability of plants to produce these extra inflorescences and fill additional seeds.