<div>Native and invasive bark and ambrosia beetles threaten the health and productivity of natural and planted forests worldwide. Management of these pests relies on semiochemical-based tactics, but these are often ineffective at monitoring for incipient populations or decreasing pest populations. The role of fungal and non-host volatiles in colonization behavior remains unknown for many important bark and ambrosia beetle species, thereby hindering their control. In this dissertation, I tested the hypothesis that fungal and tree-associated volatiles influence the host colonization behavior of bark and ambrosia beetles that affect hardwood trees. This work describes the identification of novel fungal and host-associated semiochemicals that may aid in future management of these important pests.</div><div><br></div><div>In Chapter 1, I review the current literature describing the volatile chemical ecology of bark and ambrosia beetles that inhabit hardwood trees. A review of groups with numerous identified semiochemicals, as well as considerations for future research is included.</div><div><br></div><div>In Chapter 2, I test the hypothesis that host colonization by the peach bark beetle (Phloeotribus liminaris) is chemically mediated by compounds associated with infested hosts. I found that benzaldehyde mediates colonization by the peach bark beetle, and that that benzaldehyde lures are effective attractants in field-trapping studies.</div><div><br></div><div>In Chapter 3, I test the hypothesis that ambrosia beetle attraction to host stress compounds can be modified by symbiotic fungal volatiles. I found that for three species of invasive ambrosia beetles individual fungal volatiles act as repellents, with species-specific differences in response to different compounds.</div><div><br></div><div>In Chapter 4, I test the hypothesis that attraction of the walnut twig beetle (Pityophthorus juglandis) to its pheromone lure can be enhanced by symbiotic fungal volatiles. I found that symbiotic fungal volatiles consistently enhance attraction of the beetles to their fungus, while one symbiotic fungal volatile of ambrosia beetle species repelled the walnut twig beetle.</div><div><br></div><div>In Chapter 5, I summarize results from each of the chapters and discuss patterns observed in the response to fungal and host-associated volatiles among the focal bark and ambrosia beetle species. I also discuss future research needs and directions to continue development of the knowledge surrounding scolytine chemical ecology and management of these pest beetle species.</div>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/14522331 |
| Date | 30 April 2021 |
| Creators | Matthew W Ethington (10731882) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/Role_of_Fungal_and_Host-Associated_Volatiles_in_the_Chemical_Ecology_of_Scolytine_Beetles_Affecting_Hardwood_Trees/14522331 |
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