Associational protection and potential non-target effects of systemic insecticide treatments against emerald ash borer
2022-03
Loading...
View/Download File
Persistent link to this item
Statistics
View StatisticsJournal Title
Journal ISSN
Volume Title
Title
Associational protection and potential non-target effects of systemic insecticide treatments against emerald ash borer
Authors
Published Date
2022-03
Publisher
Type
Thesis or Dissertation
Abstract
Emerald ash borer (EAB), Agrilus planipennis, is an invasive beetle that was accidentally introduced to North America from Asia. In North America, EAB attacks and kills ash trees (Fraxinus spp.). Since the 1990s the insect has spread to 35 American states and 5 Canadian provinces. A primary management strategy against EAB in urban centers is the use of systemic insecticide treatments. However, insecticide application can be very costly and induces concern about potential non-target effects on other invertebrate species and the environment. The objectives of this dissertation were to investigate the use of a treatment regime that could reduce costs, amounts of insecticides, and potential indirect negative effects on ash trees and other invertebrates. We hypothesized that treating a subset of ash trees in an urban setting could confer protective benefits to untreated trees, a strategy known as associational protection. We set up a study from summers 2017 to 2021 where 50% of boulevard ash trees at twelve sites distributed across eight cities in central and southeastern Minnesota were treated in a spatial gradient with one of two insecticides: emamectin benzoate (TREE-äge® G4) or azadirachtin (AzaSol®). Each site covered an area of approximately 1 km2 and contained approximately 100 ash trees. In general, treating a subset of trees increased the overall crown health of the study trees. We also conducted field and laboratory studies to analyze the indirect effect of insecticides on ash tree phenology and seed resources as well as non-target effects on other insect species. No adverse effects of chemical treatments were observed on ash tree phenology or seed germination or viability or time to germination. Non-target insect studies showed that there will likely be minimal effects on other invertebrates. Results from this study will assist in amending current treatment regimens using systemic insecticides and elucidate potential risks these insecticides may have on non-target invertebrates and ash trees.
Description
University of Minnesota Ph.D. dissertation. March 2022. Major: Entomology. Advisor: Brian Aukema. 1 computer file (PDF); xix 216 pages.
Related to
Replaces
License
Collections
Series/Report Number
Funding information
Isbn identifier
Doi identifier
Previously Published Citation
Suggested citation
Mwangola, Dorah. (2022). Associational protection and potential non-target effects of systemic insecticide treatments against emerald ash borer. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/227911.
Content distributed via the University Digital Conservancy may be subject to additional license and use restrictions applied by the depositor. By using these files, users agree to the Terms of Use. Materials in the UDC may contain content that is disturbing and/or harmful. For more information, please see our statement on harmful content in digital repositories.