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Full-Text Articles in Life Sciences
Surveying Eastern Hemlocks In The Northwestern Portion Of Port Sheldon Natural Area For Hemlock Woolly Adelgid, Murielle A. Garbarino
Surveying Eastern Hemlocks In The Northwestern Portion Of Port Sheldon Natural Area For Hemlock Woolly Adelgid, Murielle A. Garbarino
Honors Projects
Hemlock woolly adelgid (Adelges tsugae, HWA) is an insect native to Asia that feeds on the starches of hemlock trees (Tsuga spp.). HWA is invasive to the Eastern United States and can kill Eastern hemlock trees (Tsuga canadensis). Eastern hemlock is the only hemlock species native to Michigan. As of 2019, the invasion of HWA in Michigan is concentrated in the western portion of the lower peninsula. Monitoring is important to determine the extent of HWA within the state and to establish infested areas in need of treatment. This purpose of this project was to do a 100 percent survey …
Volatile Profiles And Resistance To Herbivory In Eastern Hemlock, Elizabeth A. Mckenzie
Volatile Profiles And Resistance To Herbivory In Eastern Hemlock, Elizabeth A. Mckenzie
Masters Theses
Eastern hemlock hosts the hemlock woolly adelgid, an introduced sap-feeding insect that causes rapid deterioration of the host. Like most conifers, eastern hemlock produces a variety of constitutive and induced defenses, primarily terpenoids. To explore the relationship of terpenoid defenses with adelgid infestations, we artificially infested hemlocks at a forest site and a plantation site, and compared their terpenoid concentrations to those in control trees. Infested trees showed lower terpenoid concentrations than control trees, suggesting that eastern hemlock not only fails to induce production of terpenoids in response to adelgid infestation, but becomes less able to produce carbon-based defenses due …
Resin Volatiles Of Eastern Hemlock Induced By Its Non-Native Herbivores, Joshua D. Pezet
Resin Volatiles Of Eastern Hemlock Induced By Its Non-Native Herbivores, Joshua D. Pezet
Masters Theses 1911 - February 2014
Eastern hemlock (Tsuga canadensis) is in decline because of infestation by the invasive hemlock woolly adelgid (Adelges tsugae; ‘HWA’) and, to a lesser extent, the elongate hemlock scale (Fiorinia externa; ‘EHS’). Many conifers respond to insect herbivory by inducing oleoresin-based defenses, however it is unknown whether eastern hemlock is capable of this inducible response. We conducted a plantation setting study of artificially infested saplings to determine if feeding by HWA or EHS induces changes in the tree’s volatile chemistry. The induced changes in volatiles we found were unlike the terpenoid-based defenses of related conifers. Only HWA feeding …