1,216 research outputs found

    Parasitism of \u3ci\u3eUrophora Affinis\u3c/i\u3e (Diptera: Tephritidae) by \u3ci\u3eAprostocetus\u3c/i\u3e Sp. (Hymenoptera: Eulophidae) in Michigan

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    (excerpt) Urophora affinis Frfld. and U. quadrifasciata (Meig.) (Diptera: Tephriti- dae) are Eurasian gallicolous fruit flies introduced to North America in 1972 as biological control agents for Centaurea biebersteinii DC (spotted knapweed, Asteraceae, = C. maculosa auct. non Lam.) (Harris 1980). Through natural dispersal and numerous introductions, both Urophora species have become distributed throughout the introduced range of C. biebersteinii (Foote et al. 1993, Lang et al. 1997, Mays and Kok 2003)

    Presence of the “Threatened” \u3ci\u3eTrimerotropis Huroniana\u3c/i\u3e (Orthoptera: Acrididae) in Relation to the Occurrence of Native Dune Plant Species and the Exotic \u3ci\u3eCentaurea Biebersteinii\u3c/i\u3e

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    Trimerotropis huroniana Wlk. is a “Threatened” species in Michigan and Wisconsin with a distribution limited to open dune systems in the northern Great Lakes region of North America. Pitfall traps were utilized in the Grand Sable Dunes of Pictured Rocks National Lakeshore, MI, along with an herbaceous plant survey, to identify the relationship of T. huroniana with native dune plant species, Ammophila breviligulata Fern. (American beachgrass, Poaceae), Artemisia campestris L. (field sagewort, Asteraceae), and the exotic invasive plant Centaurea biebersteinii DC. [=Centaurea maculosa, spotted knapweed, Lamarck] (Asteraceae). The absence of C. biebersteinii resulted in an increased likelihood of capturing T. huroniana. This was most likely due to the increased likelihood of encountering A. campestris in areas without C. biebersteinii. The occurrence of A. breviligulata was independent of C. biebersteinii presence. A significant positive linear relationship occurred between the percent cover of A. campestris and the traps that captured T. huroniana. There was no significant relationship between A. breviligulata percent cover and the traps that captured T. huroniana. The occurrence and distribution of T. huroniana is closely related to the presence and abundance of A. campestris. Habitat conservation and improvement for T. huroniana should include increases in A. campestris populations through the removal of C. biebersteinii

    Establishment, Growth, Spread, and Ecological Impacts of \u3cem\u3eMicrostegium vimineum\u3c/em\u3e in Central Hardwood Forests

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    Microstegium vimineum is an annual exotic grass common through the Southeastern United States. Adding M. vimineum to native plant communities may alter future forest composition through inhibiting the growth and influencing recruitment of seedlings into larger size classes, as well as significantly altering vertical structure and community richness, which may influence the distribution of insects. The main objectives of these studies were to 1) establish how different mineral soil and litter disturbances, in combination with various forest canopy coverage, influence the establishment, growth, and spread of M. vimineum, 2) quantify effects of competition between M. vimineum and native hardwood seedlings, and 3) identify the influence of M. vimineum on insect community structure and distribution. As percent canopy cover decreased, M. vimineum mean length and mean number of nodes increased. Also, as soil temperature and soil moisture increased, M. vimineum percent cover increased. Individual seedlings spread further from established populations in both the litter removal and the mineral soil disturbance and litter removal treatments than in the control. The apparent connection between soil disturbance and invasion by M. vimineum provides further impetus for careful planning and use of haul road and skid trails. There was a reduction in A. rubrum and L. tulipifera leaf area as a result of competition with M. vimineum, which was likely due to competition for moisture. Quercus rubra did not display any differences in leaf characteristics as a result of M. vimineum competition. As a result of reductions in growth for A. rubrum and L. tulipifera, competitive impacts imposed by M. vimineum may alter the rate at which these species are recruited into larger size classes. This may change future forest composition, and have ecological and economic consequences. In areas with M. vimineum, there were significantly more insects collected than in areas without M. vimineum. These increases in abundance likely resulted from 2.5 times greater plant cover due to the addition of M. vimineum to the plant communities. However, it should be noted that focusing on a single taxonomic group, such as insects, might not provide an adequate measure of exotic species impacts

    Parasitism of \u3ci\u3eUrophora Affinis\u3c/i\u3e (Diptera: Tephritidae) by \u3ci\u3eAprostocetus\u3c/i\u3e Sp. (Hymenoptera: Eulophidae) in Michigan

    Get PDF
    (excerpt) Urophora affinis Frfld. and U. quadrifasciata (Meig.) (Diptera: Tephriti- dae) are Eurasian gallicolous fruit flies introduced to North America in 1972 as biological control agents for Centaurea biebersteinii DC (spotted knapweed, Asteraceae, = C. maculosa auct. non Lam.) (Harris 1980). Through natural dispersal and numerous introductions, both Urophora species have become distributed throughout the introduced range of C. biebersteinii (Foote et al. 1993, Lang et al. 1997, Mays and Kok 2003)

    Insect Visitors of Cirsium pitcheri, a Threatened and Endemic Dune Species, in Relation to Annual Weather Variation

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    Cirsium pitcheri (Torr. ex Eaton) Torr. & A. Gray (Pitcher’s thistle) is a threatened herbaceous plant endemic to sand dune ecosystems along Lakes Huron, Michigan, and Superior in North America. Habitat for this plant is limited to active dunes with moving sand. I observed floral visitors of C. pitcheri in Indiana Dunes National Lakeshore and Indiana Dunes State Park, and calculated frequency and density of visitor families. Additionally, I tested for relationships between visitor counts and previous growing season mean temperature and precipitation. Formicidae, Anthomyiidae, and Cecidomyiidae were the most frequent families. However, Apidae was the only family correlated with the number of subsequent C. pitcheri seedlings. Counts of mean visitors per plant were different between years, with 2013 being the lowest. These values were related to previous growing season precipitation, which was lowest in 2012 due to a widespread severe drought. There was clear depression of floral visitor frequency and density following the 2012 drought, but that was short-lived and subsequent years displayed recovery of visitor numbers. Many of the floral visitors of C. pitcheri are likely feeding on nectar, pollen, and vegetative structures, and providing minimal, if any, pollination benefit. However, families such as Apidae and Halictidae carry visible pollen loads between multiple individual plants. Pollinator augmentation with these families may benefit C. pitcheri reproduction, especially following years of drought

    Predicting Emerald Ash Borer, \u3ci\u3eAgrilus Planipennis\u3c/i\u3e (Coleoptera: Buprestidae), Landing Behavior on Unwounded Ash

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    Detection of emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), an invasive forest pest, is difficult in low density populations war- ranting continual development of various trapping techniques and protocols. Understanding and predicting landing behavior of A. planipennis may assist in the further development of trapping techniques and improvement of trapping protocols for widespread survey programs in North America. Three multiple regression models were developed using ash tree vigor and crown light exposure to predict the landing behavior of A. planipennis. These models were then used to predict the landing density of A. planipennis at separate sites and in separate years. Successful prediction of A. planipennis capture density at the test sites was limited. Even though the multiple regression models were not effective at predicting landing behavior of A. planipennis, tree characteristics were used to predict the likelihood of A. planipennis landing. Trees predicted as having high likelihood of landing had 3.5 times as many A. planipennis adults/m2 on stem traps than trees predicted as having low likelihood of landing. While the landing density of A. planipennis may not be efficiently predicted, the utility of these predictions may be in the form of identifying trees with a high likelihood of A. planipennis landing. Those high likelihood trees may assist in improving existing detection programs and techniques in North American forests

    Presence of the “Threatened” \u3ci\u3eTrimerotropis Huroniana\u3c/i\u3e (Orthoptera: Acrididae) in Relation to the Occurrence of Native Dune Plant Species and the Exotic \u3ci\u3eCentaurea Biebersteinii\u3c/i\u3e

    Get PDF
    Trimerotropis huroniana Wlk. is a “Threatened” species in Michigan and Wisconsin with a distribution limited to open dune systems in the northern Great Lakes region of North America. Pitfall traps were utilized in the Grand Sable Dunes of Pictured Rocks National Lakeshore, MI, along with an herbaceous plant survey, to identify the relationship of T. huroniana with native dune plant species, Ammophila breviligulata Fern. (American beachgrass, Poaceae), Artemisia campestris L. (field sagewort, Asteraceae), and the exotic invasive plant Centaurea biebersteinii DC. [=Centaurea maculosa, spotted knapweed, Lamarck] (Asteraceae). The absence of C. biebersteinii resulted in an increased likelihood of capturing T. huroniana. This was most likely due to the increased likelihood of encountering A. campestris in areas without C. biebersteinii. The occurrence of A. breviligulata was independent of C. biebersteinii presence. A significant positive linear relationship occurred between the percent cover of A. campestris and the traps that captured T. huroniana. There was no significant relationship between A. breviligulata percent cover and the traps that captured T. huroniana. The occurrence and distribution of T. huroniana is closely related to the presence and abundance of A. campestris. Habitat conservation and improvement for T. huroniana should include increases in A. campestris populations through the removal of C. biebersteinii

    Applying Social Science to Bring Resident Stakeholders into Pollution Governance: A Rural Environmental Justice Public Health Case Study

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    The purpose of this engaged public sociology study was to use social science to bring resident stakeholders into the process of governing pollution production in a rural community. The community has cancer clusters. Residents have concerns about direct exposure to pollution production in their neighborhood by a steel recycling plant that has been cited numerous times for environmental violations. The facility has been under voluntary remediation since 2009, but neighborhood residents were marginalized from the governance process. This case study details how social science was used to bring neighborhood residents’ concerns about direct exposure to toxic air pollution into remediation governance. A curricula-as-research model was developed to provide an engagement framework that guided the case study as it progressed through a series of six stages over five years. The Principle Investigator maintained this collaboration by integrating the project into courses, securing small grants, developing an affordable air pollution monitoring method, and convening multiple community meetings. The air monitoring results are analyzed and discussed. Finally, the impact of the case study on the company, the state environmental management agency, local government, the nonprofit partner, and residents’ sense of human agency is evaluated

    Relationships between algal biomass and diversity with stream size and adjacent land use

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    Land use adjacent to waterways, such as development or agriculture, alters hydrological patterns leading to increases in runoff and nutrient input. Forests and wetlands, as natural land cover types, reduce water movement and allow infiltration into soil. We measured algal biomass and diversity in order to quantify the influence neighboring land cover types have on streams in Northeastern Indiana. In the study area, cultivated crops were the dominant land cover type, with open development and deciduous forest following. Emergent wetland area had the greatest influence on algal biomass, with increases in wetland area decreasing biomass. However, open development, low intensity development, grassland, shrub, and forested wetlands added to increases in biomass. Conversely, forested wetlands reduced algal richness, while open development and pastures increased richness. Because open development (i.e. dominated by turf grass, lawns, parks, golf courses) was the second most common land cover type and positively influenced both algal biomass and richness, management of those properties will likely have direct impact on nutrient flow into streams. Additionally, adding functional wetlands dominated by emergent herbaceous plants will directly impact future algal biomass

    Genome-wide SNP identification in Fraxinus linking genetic characteristics to tolerance of Agrilus planipennis

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    Ash (Fraxinus spp.) is one of the most widely distributed tree genera in North America. Populations of ash in the United States and Canada have been decimated by the introduced pest Agrilus planipennis (Coleoptera: Buprestidae; emerald ash borer), having negative impacts on both forest ecosystems and economic interests. The majority of trees succumb to attack by A. planipennis, but some trees have been found to be tolerant to infestation despite years of exposure. Restriction site-associated DNA (RAD) sequencing was used to sequence ash individuals, both tolerant and susceptible to A. planipennis attack, in order to identify single nucleotide polymorphism (SNP) patterns related to tolerance and health declines. de novo SNPs were called using SAMtools and, after filtering criteria were implemented, a set of 17,807 SNPs were generated. Principal component analysis (PCA) of SNPs aligned individual trees into clusters related to geography; however, five tolerant trees clustered together despite geographic location. A subset of 32 outlier SNPs identified within this group, as well as a subset of 17 SNPs identified based on vigor rating, are potential candidates for the selection of host tolerance. Understanding the mechanisms of host tolerance through genome-wide association has the potential to restore populations with cultivars that are able to withstand A. planipennis infestation. This study was successful in using RAD-sequencing in order to identify SNPs that could contribute to tolerance of A. planipennis. This was a first step toward uncovering the genetic basis for host tolerance to A. planipennis. Future studies are needed to identify the functionality of the loci where these SNPs occur and how they may be related to tolerance of A. planipennis attack
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