Browsing by Subject "Dendroctonus ponderosae"
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Item Data from: Development of an aggressive bark beetle on novel hosts: Implications for outbreaks in an invaded range(2017-11-11) Rosenberger, Derek W; Venette, Robert C; Aukema, Brian H; dwrosenberger@olivet.edu; Rosenberger, Derek WMountain pine beetle (Dendroctonus ponderosae Hopkins) is an aggressive bark beetle native to western North America currently expanding its range east. Should it reach northeastern North American pine forests, it is unclear how novel pine hosts might affect traits related to reproduction and development. These data are the result of studies meant to determine how four novel pine hosts might impact mountain pine beetle reproduction and development, relative to two historical hosts.Item Responses by natural enemies to semiochemicals associated with mountain pine beetle (Dendroctonus ponderosae)(2020-01) Smith, ZachMountain pine beetle (Dendroctonus ponderosae Hopkins) is an aggressive bark beetle native to North America west of the Rocky Mountains and in the Black Hills of South Dakota. Outbreaks result in mortality to mature pines over many thousands of hectares. In western North America, mountain pine beetle’s primary hosts are ponderosa (Pinus ponderosae Lawson) and lodgepole (Pinus contorta Douglas) pines. In recent decades, ameliorating winter temperatures have allowed populations of mountain pine beetle to expand their range across the biogeoclimatic barrier of the Rocky Mountains into stands of jack pine (Pinus banksiana Lamb.) in Alberta, Canada. The invaded forest is contiguous with the boreal forest of eastern North America, creating concern that mountain pine beetle will expand its range toward the Great Lakes region where it threatens evolutionarily naïve red (Pinus resinosa Ait.), eastern white (Pinus strobus L.), jack, and scots (Pinus sylvestris L.) pines. Mountain pine beetles procure hosts by responding to species-specific aggregation pheromones. Natural enemies use these and other host volatile cues as kairomones. If mountain pine beetle were to expand its range into the Great Lakes region, it would encounter new forest and insect communities that are evolutionarily naïve to its presence. My thesis investigates semiochemical responses of native insects to chemical lures of mountain pine beetle within its native range and in the potential invasion zone. In addition, I study direct competitive interactions of mountain pine beetle with the native non-aggressive bark beetle, the eastern five-spined ips (Ips grandicollis Eichoff). My work suggests very few natural enemies native to the Great Lakes region will respond to the chemical cues associated with mountain pine beetle if it were to arrive so may not be significant mortality factors.Item Susceptibility and suitability of northeastern North American pines for mountain pine beetle, Dendroctonus ponderosae Hopkins(2016-06) Rosenberger, DerekThe mountain pine beetle (Dendroctonus ponderosae Hopkins) is the most aggressive bark beetle (Coleoptera: Curculionidae) in western North America. This insect is currently expanding its range eastward through the Canadian boreal forest. Continued range expansion, or introduction via infested material from western North America, could lead to novel associations between the mountain pine beetle and eastern pines. This research seeks to determine the susceptibility and suitability of pine species common to northeastern North America for mountain pine beetle. Studies were conducted in a common garden environment on logs of four common eastern pines, red (Pinus resinosa), jack (P. banksiana), eastern white (P. strobus) and Scots (P. sylvestris) pine, and two historic hosts, lodgepole (P. contorta) and ponderosa (P. ponderosa) pine. Constitutive defenses pose no significant barrier to colonization of eastern pines by mountain pine beetle. The proportion of female beetles that established fertile egg galleries differed among eastern pines, but were similar to historic hosts. Foraging beetles were generally no more attracted to logs of eastern pines containing boring beetles than to a control. Chemical analysis of the phloem suggests that host kairomones critical for secondary attraction were minimal among novel pines and likely resulting in less attraction than to historic hosts. Overwintering capacity of developing brood was affected by eastern pines. Rapid development in novel pines resulted in greater proportions of brood entering winter in less cold tolerant life stages than historic hosts. The strategy and degree of cold tolerance of fourth instars were affected by natal pine host. Field validation of logistic regression models demonstrated that models based on the insect freezing temperature underestimate cold mortality, while lower lethal temperature curves more accurately project mortality due to cold. Finally, we found that constitutive defenses pose no barrier to reproduction among novel pines. Indeed, novel pines can have up to twice the reproductive potential, and demonstrate greater brood fitness than historic hosts. However, variable rates of development among novel hosts could result in desynchronized or extended emergence periods in mixed stands. Matches between species specific development rates and climate will be crucial for outbreaks to occur in eastern forests.