Browsing by Subject "emerald ash borer"

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    Associational protection and potential non-target effects of systemic insecticide treatments against emerald ash borer
    (2022-03) Mwangola, Dorah
    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.
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    Biosurveillance with the smokey winged beetle bandit wasp: understanding buprestid populations and volunteer outcomes in Minnesota
    (2019-08) Hallinen, Marie
    Buprestid beetles can be difficult to sample due to their cryptic nature: larvae are usually wood-boring and feed under bark or within stems, and adults exhibit maturation feeding within tree canopies. There is no long-range sex pheromone identified for this family that could be exploited for sampling. In addition, currently available traps are only intermittently successful at detecting species of interest, including the invasive emerald ash borer, Agrilus planipennis Fairmaire, when at low densities. One method used to sample emerald ash borer and other buprestids is biosurveillance with a native ground-nesting hunting wasp, Cerceris fumipennis Say (Hymenoptera: Crabronidae). Cerceris fumipennis hunts for a wide range of buprestids, does not sting humans, and tends to nest at easily accessible human-disturbed sites such as baseball diamonds, making it easy for non-specialists to monitor nests and collect beetles in their communities. This work utilizes C. fumipennis-collected beetles along with existing museum records to create a checklist of buprestid species in Minnesota, investigates site-level variables that may influence the number and diversity of beetles collected by C. fumipennis, and elucidates individual outcomes for citizen science volunteers who monitor nesting aggregations of C. fumipennis.
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    Checklist of Minnesota Buprestidae Appendix: Distributional Maps
    (2020-04-08) Hallinen, Marie J; Wittman, Jacob T; Steffens, Wayne P; Schultz, Jennifer L; Aukema, Brian H; MarieHallinen@gmail.com; Hallinen, Marie J; University of Minnesota Forest Entomology Lab
    We utilized a biosurveillance sampling method, namely the use of the native ground-nesting hunting wasp Cerceris fumipennis, along with University of Minnesota Insect Collection (UMSP) records, to create a checklist for Buprestidae in Minnesota, USA. We examined 5,127 specimens with Minnesota localities, documenting 107 species. Of these, 37 new state records are noted, including 11 collected from C. fumipennis nesting sites between 2013 and 2018. Maps displaying the number of beetles for a given species caught in each county and the time passed since last collection (within 20 years) are provided here as an appendix.
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    Data and code for forecasting overwintering mortality of Spathius galinae in North America
    (2021-04-26) Wittman, Jacob T; Aukema, Brian H; Duan, Jian J; Venette, Robert C; wittm094@@umn.edu; Wittman, Jacob T
    From publication: Evaluating the cold tolerance of biological control agents is often necessary to optimize their release and performance. We used field and laboratory assays to determine the cold hardiness of the parasitoid Spathius galinae Belokobylskij & Strazanac, an approved classical biological control agent of emerald ash borer (Agrilus planipennis Fairmaire) in North America. Supercooling points and lower lethal temperature of mature (cocooned) S. galinae larvae were measured in controlled cooling assays in the laboratory. Most S. galinae larvae died after reaching their supercooling point, which occurred at -25.0°C on average. Several larvae, however, initiated freezing but later eclosed, suggesting S. galinae may be partially freeze tolerant. Supercooling points were not affected by chilling rate. In the winter of 2019 – 2020, we monitored development of mature S. galinae larvae in ash segments above and beneath the snow in three locations in Minnesota, USA. Nearly 100% of S. galinae larvae died after air temperatures reached -29°C in Minnesota. Using models developed from our data, we forecast eclosion rates of S. galinae based on minimum winter temperatures across the range of ash (Fraxinus spp.) in North America. Our results indicate that S. galinae populations may suffer high overwintering mortality in areas where winter temperatures regularly decrease below -28°C, but a small portion of the population may be able to survive lower temperatures.
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    Effects of Flooding and Light on the Performance of Potential Replacement Species in Black Ash Wetland Forests
    (2022-04) Keller, Gwendolen
    Within black ash wetlands in the western Great Lakes region, black ash (Fraxinus nigra Marshall) is a foundational species that controls hydrologic regime, nutrient cycling, and wildlife habitat. The role of black ash in these stands makes them particularly vulnerable to the invasive emerald ash borer (EAB) (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae). One strategy that has been suggested to mitigate the impact of this invasive insect is the increase of tree species diversity through artificial regeneration, however, there is limited information available on how potential replacement tree species respond to shade and flooding. We used controlled greenhouse and field experiments that manipulated flooding duration and intensity as well as shade to explore early survival, growth, and physiology of 23 different tree species that vary in shade and flood tolerance. Measurements of seedling physiology, growth, and survival were taken throughout the growing seasons of 2020 and 2021. Results indicate that bald cypress was able to tolerate the most extreme flooding conditions simulated in the study: water table at the soil surface for 15 weeks. American elm, sycamore, and river birch were tolerant of water tables between 0 and 14 cm below the soils surface for up to 15 weeks. Northern white cedar, red maple, tamarack, swamp white oak, and yellow birch had high survival and growth rates with the water table at the soil surface for up to 6 weeks. Finally, black walnut, sugar maple, white spruce, white oak, red pine, and bitternut hickory responded poorly to flooding of any duration. Results indicate that water table depth has a greater influence on seedling growth and gas exchange rates than light reduction, especially at light levels likely to be found in black ash wetlands. Since shade treatments were generally not a significant impediment to early growth, survival, and gas exchange rates, natural resource managers should focus on matching the flood tolerance of potential replacement species to local site hydrology.
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    Managing Ash Woodlands: Recommendations for Minnesota Woodland Owners
    (University of Minnesota Extension, 2019) University of Minnesota Extension
    This document provides ash management recommendations for private woodland owners in Minnesota. After the emerald ash borer (EAB) was found in Minnesota in 2009, the University of Minnesota Extension and the MN Department of Natural Resources (DNR) quickly recognized the need to offer practical and timely ash management recommendations for woodland owners. This document synthesizes expert woodland recommendations presented in previous publications in addition to scientific results from on-the-ground research studies.
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    Managing Emerald Ash Borer: A Resilient Communities Project–GreenStep Cities Guide
    (Resilient Communities Project (RCP), University of Minnesota., 2016) Strain, Sarah (editor)
    This decision document helps local government agencies develop an emerald ash borer management plan based on the “acceptable risks” the community is willing to take ecologically, economically, and socially to manage the problem. This resource was prepared by the University of Minnesota’s Resilient Communities Project (RCP) for the Minnesota GreenStep Cities Program. The resource was developed from work completed by two teams of students through a partnership between RCP and the City of North St. Paul, Minnesota, during the 2013–2014 academic year. Although the original reports were developed for a specific community, the students’ findings and recommendations have been synthesized and generalized, and additional research has been conducted where necessary, to produce a resource that is relevant to communities throughout Minnesota. The original student reports can be found at https://conservancy.umn.edu/handle/11299/194801 and https://conservancy.umn.edu/handle/11299/194802. 
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    Minnesota Forest Land Area Estimation Using National Forest Inventory Data
    (University of Minnesota, 2019-05) Edgar, Christopher; Carson, Michael; Young, John
    The United States conducts a national forest inventory (NFI) for the purpose of providing information on the forest resources of the nation. The United States Forest Service, through the Forest Inventory and Analysis (FIA) program, administers the NFI in cooperation with state forestry agencies. NFI data and information are used by states to support forest management and policy decision-making. Here we review the sample design and estimation procedures of the NFI, with special emphasis on those aspects related to forest land area. Using the 2017 inventory data for the state of Minnesota, we compute an estimate of 17.7 million acres of forest land with a sampling error of 0.52%. Our estimate matches that published by FIA. This report documents the process of obtaining and organizing the data and application of formulae to compute the estimate and associated estimate of sampling error. All data and calculations are assembled in an MS Excel worksheet as a resource for anyone seeking to develop a fuller understanding of this important data set and appropriate estimation procedures. We then extend the estimation to that of ash forest land area, information needed for assessment of potential impacts of the emerald ash borer. For 2017, we estimate that ash (black, green, and white) is a component (at least some live volume) on 4.33 million acres, is 25% or more live volume on 1.78 million acres, and is 50% or more of live volume on 1.10 million acres of forest land in the state.
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    Perspectives on Ash Wood Utilization and Marketing in Minnesota
    (2020-08-31) Russell, Matthew B; Ring, Elizabeth C; russellm@umn.edu; Russell, Matthew B; University of Minnesota Department of Forest Resources
    In 2019 the University of Minnesota surveyed forest products companies and natural resource managers about the use of ash wood and the future of the ash resource in Minnesota given the current and future distribution of the emerald ash borer. The survey was used to gain knowledge on the current and future use of ash wood in Minnesota. This information has provided information to researchers and managers on current and future approaches to utilize forest products from ash trees.
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    Silvicultural Options to Promote Resilience of Northern Great Lakes Fraxinus nigra (Black Ash) Forests following Emerald Ash Borer (Agrilus planipennis) Invasion
    (2017-05) Looney, Christopher
    Fraxinus nigra (black ash), a dominant species of northeastern North American wetland forests, is threatened by the invasive insect, emerald ash borer (Agrilus planipennis, EAB). The potential for one or more tree species to replace F. nigra and approaches for facilitating this replacement have not been explored. To fill these knowledge gaps, this research examined: (1) the influence of competition and climate on the growth of mature F. nigra in association with Tilia americana (basswood), Populus tremuloides (quaking aspen), and Thuja occidentalis (northern white-cedar) at the mesic, moist, and wet F. nigra forest margins, respectively; (2) the survival and growth of planted seedlings of 12 potential F. nigra replacement species under four canopy treatments: unharvested control, clearcut, Fraxinus girdling to emulate EAB, and group selection; and (3) the response of F. nigra forest groundlayer plant communities to treatment-induced canopy changes. The research goals were to determine (1) how the influences of climate and competition vary by species in F. nigra forests and whether these factors shift in importance along a gradient of waterlogging stress; (2) the most promising combinations of species and treatment for silvicultural efforts to maintain post-EAB forest function; and (3) the extent to which natural regeneration of associated tree species can be expected to aid in maintaining post-EAB forest cover, as well as the potential effects on this regeneration of EAB- and treatment-induced shifts in groundlayer community composition. The main findings were that mature F. nigra had slower growth and appeared more sensitive to competition than T. americana and P. tremuloides, while having similar growth and appearing less sensitive to competition than T. occidentalis. Fraxinus nigra growth showed greater sensitivity to precipitation and temperature across the gradient of waterlogging stress relative to the three associated species. Canopy treatment type interacted with species to influence the survival and relative growth rate (RGR) of planted seedlings. Planted seedlings of shade-intolerant species generally had moderate-to-low survival and high RGR across treatments, while shade-tolerant species had higher survival with lower RGR. Natural tree regeneration varied by treatment and fell short of F. nigra forest stocking recommendations. Graminoid cover increased in the clearcut treatment, while bottomland shrubs and wetland indicator species were more numerous in the control and girdle. Overall, the findings suggest that planting seedlings of non-Fraxinus tree species with or without overstory treatment as EAB approaches is a potentially viable and necessary management option for sustaining ecosystem services in F. nigra wetlands. Site, species, and canopy treatment selection should be coordinated to maximize artificial regeneration success.