Effects Of Bagging Capitula On Plant Seed Production Of 8 Compositae Species And Growth Of Their Predispersal Seed Predators

Flowering plants interact simultaneously with mutualistic pollinators and antagonistic herbivores,and hence elucidating the complex interactions among plants-pollinators-herbivores is crucial to understanding the ecology and evolutionary biology of plants.Climate change and pesticide spraying have largely decreased the pollinator abundance and services,and the ecological consequence has received much attention.The decline of pollinator abundance may directly reduce seed set rate and seed production of angiosperms and indirectly change the interaction between plants and predispersal seed predators.However,such an effect of pollinators on plant herbivore performance has scarcely been examined.I determined the effect of pollinators on plant seed production of 8 Compositae species and the growth of tephritid fly species that consume developing seeds to complete life histories by bagging plant capitula in the alpine meadow of Hongyuan County,Sichuan Province,the eastern Qinghai-Tibet Plateau.I also evaluated the fitness consequence of pollinators and seed predators on the study plant species.I obtained the following results.(1)Except for the Taraxacum species,all the other species were demonstrated to be self-incompatible and to decrease seed set rate and seed production.(2)Capitula bagging decreased the growth rate of the large bodied fly species but not small ones.(3)Bagged capitula suffered a higher proportion of seed loss due to the seed predators.(4)Bagging capitula increased the infestation rate of tephritid flies in two of the plant species,indicating a strong resource competition between the fly species and some other seed predator species.My study demonstrated the significant effect of pollinators on the performance of predispersal seed predators,and thus it can be an important addition to the current advance of research on the relationship among plants-pollinators-herbivores.