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Influences Of Host Size And Host Quality On Host Use In A Seed-Feeding Beetle, Angela Rocío Amarillo-Suárez

University of Kentucky Doctoral Dissertations

For insects that develop inside discrete hosts both host size and host quality constrain offspring growth, influencing the evolution of body size and life history traits. This dissertation examines the effects of host size, host quality, and intraspecific competition on life history and associated traits of populations of the seed-feeding beetle S. limbatus adapted to different host plants, and quantifies population differences in phenotypic plasticity. Populations of the study correspond to divergent clades of the species phylogeography (Colombia and United States).

Clades compared differ genetically for all traits when beetles were raised in a common garden. Contrary to expectations from …

Localization Of Diplodia Pinea In Diseased And Latently-Infected Pinus Nigra, Jennifer Lee Flowers

University of Kentucky Doctoral Dissertations

Diplodia pinea causes Diplodia tip blight on more than 30 different pine species. During the past 10 years, Diplodia tip blight has emerged as a serious problem in landscape and Christmas tree farms in this region. Surveys of diseased and symptomless Austrian pines revealed that latent infections of symptomless shoots by D. pinea were common. Latent infections may account for the recently observed rapid decline of mildly diseased pines in our region. To investigate the colonization habits of D. pinea within its host, molecular cytology was attempted and traditional histology was performed on naturally infected, diseased and asymptomatic Austrian pine …