Medina, Lilhac2023-03-272023-03-272023-01https://hdl.handle.net/11299/253411University of Minnesota Ph.D. dissertation. January 2023. Major: Integrated Biosciences. Advisor: Timothy Craig. 1 computer file (PDF); v, 134 pages.The evolution of plants and herbivores is strongly influenced by anthropogenic changes in theirenvironment such as invasive species. This can lead to an outbreak of pests, and a decline in native species. Tall goldenrod, Solidago altissima, is a widespread species native to the USA and a host plant to many arthropod species. Goldenrod is also invasive in many countries, including Japan, and the invasive populations has facilitated the introduction of herbivore species. The susceptibility of the tall goldenrod to herbivory is a result of intraspecific phenotypic variation at large and small spatial scales as a result of adaptation to local abiotic and biotic factors. I set up common garden experiments of seven S. altissima populations to examine 1) differences in phenological and morphological differences of tall goldenrod populations and 2) the effect of these differences on six common herbivores of tall goldenrod. I predicted that insect specialization would influence herbivore choice for goldenrod phenotypes. The results showed that there are phenotypic differences among the goldenrod populations and these phenotypes are determined by genetic × environmental effects. Additionally, the hypothesis that insect specialization would influence herbivore choice for goldenrod phenotypes was also supported. Overall, goldenrod variation differed across large ranges due to local adaptation, but there is also variation within populations that is maintained, and this makes S. altissima successful at colonization and adapting to changes in the environment. This intraspecific plant variation influenced herbivore community composition and abundance giving insight into how bottom-up effects lead to pest outbreaks and invasive herbivores.enThesis or Dissertation