Rust fungi are some of the most devastating plant pathogens. Research efforts have therefore focused on the genetic basis for resistance to the pathogens and on other methods of control. However, by focusing on the hosts, we have learned very little about the pathogens themselves. The proposed research uses an extraordinary case of rust induced floral mimicry to explore the consequences of insect mediated gamete transfer by these fungi. Because this system appears to be highly evolved, it is ideal for studying the importance of insect-interactions for the evolution of the rust fungi. First, whether the mimicry is an evolved system, or whether it is merely the result of an accidental combination of host morphology and fungal hormones, will be examined. Next how important this extreme case of mimicry is for these particular fungi, that is, does the mimicry increase visitation by insects, and does increased visitation matter to the reproductive success of the fungi, will be assessed. Insects are known to transfer gametes of rusts, but how necessary they are under natural conditions is not well understood. Finally, the possibility that these flower-mimic fungi may affect the reproductive success of co-occurring true flowers, either by competing for pollinators or by attracting a larger pollinator population will be explored.
