Specialist pollinating seed predator exhibits oviposition strategy consistent with optimal oviposition theory

Abstract The outcome of mutualistic interactions depends on the costs and benefits for each of the partners, which have been shown to be both context‐ and species‐dependent. This phenomenon is seen in the interactions between plants in the genus Silene and moths in the genus Hadena . In this study, the interaction between native North American species Silene stellata and Hadena ectypa is examined to understand the factors that influence female H. ectypa oviposition decisions, a behaviour that influences both herbivore and plant fitness. While most studies focus on oviposition preference between different host plant species, here it is shown that for a specialist pollinating seed predator, oviposition preference occurs within a host species (and even within a plant) based upon individual flower age and pollination status. Female H. ectypa preferentially visited and oviposited on young flowers and flowers that were unpollinated. Larvae also preferred to feed on young fruits. Female H. ectypa oviposition choice was consistent with optimal oviposition theory, as oviposition preference was correlated with larval feeding preference and not just adult visitation preference.