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Invasion Is Contingent On Species Assemblage And Invasive Species Identity Inexperimental Rehabilitation Plots, A. Joshua Leffler, Eamonn D. Leonard, Jeremy J. James, Thomas A. Monaco Nov 2014

Invasion Is Contingent On Species Assemblage And Invasive Species Identity Inexperimental Rehabilitation Plots, A. Joshua Leffler, Eamonn D. Leonard, Jeremy J. James, Thomas A. Monaco

Natural Resource Management Faculty Publications

Ecological studies often suggest that diverse communities are most resistant to invasion by exotic plants, but relatively few local species may be available to a rehabilitation practitioner. We examine the ability of monocultures and diverse assemblages to resist invasion by an exotic annual grass (cheatgrass) and an exotic biennial forb (dyer’s woad) in experimental rehabilitation plots. We constructed seven assemblages that included three monocultures of grass, forb, or shrub; three four-species mixtures of grasses, forbs, or shrubs; and a three-species mixture of one species from each growth form in an experimental field setting to test resistance to invasion. Assemblages were …


Water Resources And The Historic Wells Of Barbuda: Tradition, Heritage And Hope For A Sustainable Future, Rebecca Boger, Sophia Perdikaris, Amy E. Potter, John Mussington Nov 2014

Water Resources And The Historic Wells Of Barbuda: Tradition, Heritage And Hope For A Sustainable Future, Rebecca Boger, Sophia Perdikaris, Amy E. Potter, John Mussington

Earth, Environment & Sustainability: Faculty Publications

The island of Barbuda has a relatively unique history, land tenure and geography. Unlike its Caribbean counterparts, the island is not suited to large-scale agriculture due to its arid climate and relatively thin soils. Instead, the enslaved and eventually free people of Barbuda developed a complex herding ecology centered on common land ownership. As a result, carefully designed historic wells are strategically located around the island. With the challenges brought about by climate change, an interdisciplinary, international team led by the Barbuda Research Complex is investigating the state of existing water and food resources and examining how the availability and …


Coastal Lagoons And Estuaries In Mexico: Processes And Vulnerability, Victor F. Camacho-Ibar, Victor H. Rivera-Monroy Oct 2014

Coastal Lagoons And Estuaries In Mexico: Processes And Vulnerability, Victor F. Camacho-Ibar, Victor H. Rivera-Monroy

Faculty Publications

No abstract provided.


Octopus Tetricus (Mollusca: Cephalopoda) As An Ecosystem Engineer, David Scheel, Peter Godfrey-Smith, Matthew Lawrence Oct 2014

Octopus Tetricus (Mollusca: Cephalopoda) As An Ecosystem Engineer, David Scheel, Peter Godfrey-Smith, Matthew Lawrence

Publications and Research

The Sydney octopus (Octopus tetricus) occurs in unusual numbers on a shell bed of its prey remains that have accumulated as an extended midden where additional octopuses excavate dens. Here, O tetricus are ecosystem engineers, organisms that modulate availability of resources to other species and to their own species by causing physical state changes in materials. A community of invertebrate grazers and scavengers has developed on the shell bed. Fishes are attracted to the shell bed in numbers significantly greater than in nearby habitats. Large predators, including wobbegong sharks, were attracted to and fed on concentrations of fish, inhibiting the …


Tree Spatial Structure, Host Composition And Resource Availability Influence Mirid Density Or Black Pod Prevalence In Cacao Agroforests In Cameroon, Cynthia Gidoin, Régis Babin, Leïla Bagny Beilhe, Christian Cilas, Gerben Martijn Ten Hoopen, Marie Ange Ngo Bieng Oct 2014

Tree Spatial Structure, Host Composition And Resource Availability Influence Mirid Density Or Black Pod Prevalence In Cacao Agroforests In Cameroon, Cynthia Gidoin, Régis Babin, Leïla Bagny Beilhe, Christian Cilas, Gerben Martijn Ten Hoopen, Marie Ange Ngo Bieng

All Peer-Reviewed Publications

Combining crop plants with other plant species in agro-ecosystems is one way to enhance ecological pest and disease regulation mechanisms. Resource availability and microclimatic variation mechanisms affect processes related to pest and pathogen life cycles. These mechanisms are supported both by empirical research and by epidemiological models, yet their relative importance in a real complex agro-ecosystem is still not known. Our aim was thus to assess the independent effects and the relative importance of different variables related to resource availability and microclimatic variation that explain pest and disease occurrence at the plot scale in real complex agro-ecosystems. The study was …


Remote Sensing Estimates Of Stand-Replacement Fires In Russia, 2002–2011, Alexander Krylov, Jessica L. Mccarty, Peter Potapov, Tatiana Loboda, Alexandra Tyukavina, Svetlana Turubanova, Matthew Hansen Oct 2014

Remote Sensing Estimates Of Stand-Replacement Fires In Russia, 2002–2011, Alexander Krylov, Jessica L. Mccarty, Peter Potapov, Tatiana Loboda, Alexandra Tyukavina, Svetlana Turubanova, Matthew Hansen

Michigan Tech Research Institute Publications

The presented study quantifies the proportion of stand-replacement fires in Russian forests through the integrated analysis of Landsat and Moderate Resolution Imaging Spectroradiometer (MODIS) data products. We employed 30 m Landsat Enhanced Thematic Mapper Plus derived tree canopy cover and decadal (2001–2012) forest cover loss (Hansen et al 2013 High-resolution global maps of 21st-century forest cover change Science 342 850–53) to identify forest extent and disturbance. These data were overlaid with 1 km MODIS active fire (earthdata.nasa.gov/data/near-real-time-data/firms) and 500 m regional burned area data (Loboda et al 2007 Regionally adaptable dNBR-based algorithm for burned area mapping from …


The Wandering Spider Guild Of Webb County, Texas, Monica Trevino Oct 2014

The Wandering Spider Guild Of Webb County, Texas, Monica Trevino

Theses and Dissertations

Analysis of 10 years of spider collecting in Webb County, Texas has yielded 549 specimens in 21 genera and 55 species. This study was performed to establish similarities and relationships among wandering spiders of south Texas in Webb County and to identify the members of the wandering spider guild. The families included in this guild are the Clubionidae, Corinnidae, Gnaphosidae, Liocranidae, and Miturgidae. Wet pitfall traps and hand collecting were utilized in the gathering of the specimens. Spiders were identified using the most recent literature and allowed for an examination of the interactions of the members of this guild based …


Historical Vegetation Of Three Salmon-Bearing Watersheds In The Interior Columbia River Basin, Tyanna Smith Oct 2014

Historical Vegetation Of Three Salmon-Bearing Watersheds In The Interior Columbia River Basin, Tyanna Smith

PSU McNair Scholars Online Journal

Land use practices can be a contributing factor to environmental degradation and have been the focus of many ecological studies. One aspect that is less addressed is land use history and the effects that past practices, such as logging and grazing, can have on the current landscape. This paper describes research and the synthesis of material on the environmental history and watershed characteristics for three watersheds located within spawning and rearing areas for Chinook salmon in the Grande Ronde River Basin in Northeast Oregon: upper Grande Ronde River, Catherine Creek, and Minam River. The Grande Ronde Basin is critical spawning …


Consumption Of Low-Moderate Level Arsenic Contaminated Water Does Not Increase Spontaneous Pregnancy Loss: A Case Control Study, Michael S. Bloom, Iulian Neamtiu, Simona Surdu, Cristian Pop, Ioana-Rodica Lupsa, Doru Anastasiu, Edward F. Fitzgerald, Eugen S. Gurzau Oct 2014

Consumption Of Low-Moderate Level Arsenic Contaminated Water Does Not Increase Spontaneous Pregnancy Loss: A Case Control Study, Michael S. Bloom, Iulian Neamtiu, Simona Surdu, Cristian Pop, Ioana-Rodica Lupsa, Doru Anastasiu, Edward F. Fitzgerald, Eugen S. Gurzau

Environmental Health Sciences Faculty Scholarship

Previous work suggests an increased risk for spontaneous pregnancy loss linked to high levels of inorganic arsenic (iAs) in drinking water sources (>10 μg/L). However, there has been little focus to date on the impact of low-moderate levels of iAs in drinking water (<10 >μg/L). To address this data gap we conducted a hospital-based case–control study in Timis County, Romania.


Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown Oct 2014

Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Global climate change is altering the breeding phenology of many organisms, and one reported consequence of warmer average temperatures is earlier breeding times in migratory songbirds of north temperate latitudes. Less studied are the potential interactions between earlier breeding and social behavior in colonial species. We investigated how breeding time, as measured by colony initiation dates across the entire summer, in Cliff Swallows (Petrochelidon pyrrhonota) of southwestern Nebraska, USA, changed over a 30-year period and could be predicted by climatic variables, year, and colony size. Mean colony initiation date became earlier over the study, with variation best predicted …


Importance Of School Library Programs, Cynthia Strong Oct 2014

Importance Of School Library Programs, Cynthia Strong

SPU Works

Within the discipline of library science, over 20 research studies have been done in the United States attesting to how high-quality school library programs contribute to improved academic achievement. On the other hand, in the fields of education, school counseling, administration, and school leadership, and so on, there is a dearth of scholarship and recognition of the positive impact librarians and library media program have on student success. This conceptual paper first presents an overview of the empirical research on school library programs and the positive impact they have on the academic achievement of students in the United States. Second, …


Effects Of Biomass Harvest On Eastern Red-Backed Salamanders, Patrick J. Ruhl Oct 2014

Effects Of Biomass Harvest On Eastern Red-Backed Salamanders, Patrick J. Ruhl

Open Access Theses

In a typical forest harvest, the volume of coarse woody debris (CWD) increases from nonmerchantable material (i.e., tree-tops, limbs, and small-diameter trees) left on the forest floor. Biomass harvesting removes much of this material for bioenergy production. When removed, ecosystem services associated with CWD, such as seedbed substrate, nutrient cycling, and essential wildlife habitat, is reduced. Woodland salamanders have strict microhabitat and soil moisture requirements that make them especially sensitive to timber harvest practices, particularly those that remove CWD, a primary habitat for the group.

I monitored the abundance of Eastern red-backed salamanders ( Plethodon cinereus ) in response to …


Energy-Efficient Information Inference In Wireless Sensor Networks Based On Graphical Modeling, Wei Zhao Oct 2014

Energy-Efficient Information Inference In Wireless Sensor Networks Based On Graphical Modeling, Wei Zhao

Open Access Dissertations

This dissertation proposes a systematic approach, based on a probabilistic graphical model, to infer missing observations in wireless sensor networks (WSNs) for sustaining environmental monitoring. This enables us to effectively address two critical challenges in WSNs: (1) energy-efficient data gathering through planned communication disruptions resulting from energy-saving sleep cycles, and (2) sensor-node failure tolerance in harsh environments. In our approach, we develop a pairwise Markov Random Field (MRF) to model the spatial correlations in a sensor network. Our MRF model is first constructed through automatic learning from historical sensed data, by using Iterative Proportional Fitting (IPF). When the MRF model …


How Discordant Morphological And Molecular Evolution Among Microorganisms Can Revise Our Notions Of Biodiversity On Earth, Daniel J.G. Lahr, Haywood Dail Laughinghouse, Angela M. Oliverio, Feng Gao, Laura A. Katz Oct 2014

How Discordant Morphological And Molecular Evolution Among Microorganisms Can Revise Our Notions Of Biodiversity On Earth, Daniel J.G. Lahr, Haywood Dail Laughinghouse, Angela M. Oliverio, Feng Gao, Laura A. Katz

Biological Sciences: Faculty Publications

Microscopy has revealed tremendous diversity of bacterial and eukaryotic forms. Recent molecular analyses show discordance in estimates of biodiversity between morphological and molecular analyses. Moreover, phylogenetic analyses of the diversity of microbial forms reveal evidence of convergence at scales as deep as interdomain: morphologies shared between bacteria and eukaryotes. Here, we highlight examples of such discordance, focusing on exemplary lineages such as testate amoebae, ciliates, and cyanobacteria. These have long histories of morphological study, enabling deeper analyses on both the molecular and morphological sides. We discuss examples in two main categories: (i) morphologically identical (or highly similar) individuals that are …


The Most Important Current Research Questions In Urban Ecosystem Services, James Salzman, Craig Anthony (Tony) Arnold, Robert Garcia, Keith Hirokawa, Kay Jowers, Jeffrey Lejava, Margaret Peloso, Lydia Olander Oct 2014

The Most Important Current Research Questions In Urban Ecosystem Services, James Salzman, Craig Anthony (Tony) Arnold, Robert Garcia, Keith Hirokawa, Kay Jowers, Jeffrey Lejava, Margaret Peloso, Lydia Olander

Duke Environmental Law & Policy Forum

No abstract provided.


Persistence And Change In Community Composition Of Reef Corals Through Present, Past, And Future Climates, Robert Van Woesik, Peter J. Edmunds, Mehdi Adjeroud, Marissa L. Baskett, Iliana B. Baums, Ann F. Budd, Robert C.C. Carpenter, Nicholas S. Fabina, Tungyung Fan, Eric C. Franklin Oct 2014

Persistence And Change In Community Composition Of Reef Corals Through Present, Past, And Future Climates, Robert Van Woesik, Peter J. Edmunds, Mehdi Adjeroud, Marissa L. Baskett, Iliana B. Baums, Ann F. Budd, Robert C.C. Carpenter, Nicholas S. Fabina, Tungyung Fan, Eric C. Franklin

Ocean Engineering and Marine Sciences Faculty Publications

The reduction in coral cover on many contemporary tropical reefs suggests a different set of coral community assemblages will dominate future reefs. To evaluate the capacity of reef corals to persist over various time scales, we examined coral community dynamics in contemporary, fossil, and simulated future coral reef ecosystems. Based on studies between 1987 and 2012 at two locations in the Caribbean, and between 1981 and 2013 at five locations in the Indo-Pacific, we show that many coral genera declined in abundance, some showed no change in abundance, and a few coral genera increased in abundance. Whether the abundance of …


Selenium In Rice And Esophageal Cancer, Sora Yasril, Viroj Wiwanitkit, Hadi Rahimzadeh-Barzoki, Hamidreza Joshaghani, Gholamreza Roshandel Oct 2014

Selenium In Rice And Esophageal Cancer, Sora Yasril, Viroj Wiwanitkit, Hadi Rahimzadeh-Barzoki, Hamidreza Joshaghani, Gholamreza Roshandel

Saudi Medical Journal

No abstract provided.


Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands, Mariano Soley Oct 2014

Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands, Mariano Soley

Dissertations, Theses, and Capstone Projects

This dissertation focused on the methodological and theoretical improvement of correlative ecological niche models (ENMs) to better understand the processes governing species distributions and associated evolutionary divergence in rodents inhabiting mesic conditions in the Neotropics. Focusing on a widespread rodent from northern South America (Heteromys anomalus), in the first chapter I proposed and tested a methodological approach to surmount the challenge of incorporating environmental information from the margins of species geographic ranges into ENMs. In so doing, I argue how populations that exist on the borders of species' local ranges (spatial margins) can lead to exaggerated estimates of their niches …


Ethnomedical, Ecological And Phytochemical Studies Of The Palauan Flora, Christopher Kitalong Oct 2014

Ethnomedical, Ecological And Phytochemical Studies Of The Palauan Flora, Christopher Kitalong

Dissertations, Theses, and Capstone Projects

There has been a serious deterioration of Palauan culture, language and traditional practices over the last century. To promote health and avoid this deterioration of tradition, ecological, ethnobotanical and phytochemical studies have been carried out on the plant Phaleria nisidai Kaneh. (Thymelaeaceae), "Delal a Kar", Palauan for "Mother of Medicine". This study is the first study that sets the foundations for the development of natural Palauan therapeutics, through validation of ethnomedically significant plants. Validations of these plants is done through documenting Palauan plant ethnomedical data; mapping the distribution of Palauan plants on limestone Rock Islands; and analyzing ethnopharmacological and phytochemical …


From Medicine To Butterflies And Back Again, C Parmesan Sep 2014

From Medicine To Butterflies And Back Again, C Parmesan

School of Biological and Marine Sciences

My research focuses on the current impacts of climate change on wildlife, from field-based work on butterflies to synthetic analyses of global impacts on a broad range of species across terrestrial and marine biomes. I work actively with governmental agencies and NGOs to help develop conservation assessment and planning tools aimed at preserving biodiversity in the face of climate change.


Millennial Minimum Temperature Variations In The Qilian Mountains, China: Evidence From Tree Rings, Yong Zhang, Xuemei Shao, Zhi-Yong Yin, Yang Wang Sep 2014

Millennial Minimum Temperature Variations In The Qilian Mountains, China: Evidence From Tree Rings, Yong Zhang, Xuemei Shao, Zhi-Yong Yin, Yang Wang

Environmental and Ocean Sciences: Faculty Scholarship

A 1343-year tree-ring chronology was developed from Qilian junipers in the central Qilian Mountains of the northeastern Tibetan Plateau (TP), China. The climatic implications of this chronology were investigated using simple correlation, partial correlation and response function analyses. The chronology was significantly positively correlated with temperature variables prior to and during the growing season, especially with monthly minimum temperature. Minimum temperature anomalies from January to August since AD 670 were then reconstructed based on the tree-ring chronology. The reconstruction explained 58% of the variance in the instrumental temperature records during the calibration period (1960–2012) and captured the variation patterns in …


Spatial And Temporal Patterns Of Carbon Storage In Forest Ecosystems On Hainan Island, Southern China, Hai Ren, Linjun Li, Qiang Liu, Xu Wang, Yide Li, Dafeng Hui, Shuguang Jian, Jun Wang, Huai Yang, Hongfang Lu, Guoyi Zhou, Xuli Tang, Qianmei Zhang, Dong Wang, Lianlian Yuan, Xubing Chen Sep 2014

Spatial And Temporal Patterns Of Carbon Storage In Forest Ecosystems On Hainan Island, Southern China, Hai Ren, Linjun Li, Qiang Liu, Xu Wang, Yide Li, Dafeng Hui, Shuguang Jian, Jun Wang, Huai Yang, Hongfang Lu, Guoyi Zhou, Xuli Tang, Qianmei Zhang, Dong Wang, Lianlian Yuan, Xubing Chen

Biology Faculty Research

Spatial and temporal patterns of carbon (C) storage in forest ecosystems significantly affect the terrestrial C budget, but such patterns are unclear in the forests in Hainan Province, the largest tropical island in China. Here, we estimated the spatial and temporal patterns of C storage from 1993–2008 in Hainan's forest ecosystems by combining our measured data with four consecutive national forest inventories data. Forest coverage increased from 20.7% in the 1950s to 56.4% in the 2010s. The average C density of 163.7 Mg C/ha in Hainan's forest ecosystems in this study was slightly higher than that of China's mainland forests, …


Inferred Vs Realized Patterns Of Gene Flow: An Analysis Of Population Structure In The Andros Island Rock Iguana., Giuliano Colosimo, Charles R. Knapp, Lisa E. Wallace, Mark E. Welch Sep 2014

Inferred Vs Realized Patterns Of Gene Flow: An Analysis Of Population Structure In The Andros Island Rock Iguana., Giuliano Colosimo, Charles R. Knapp, Lisa E. Wallace, Mark E. Welch

CAS Publications

Ecological data, the primary source of information on patterns and rates of migration, can be integrated with genetic data to more accurately describe the realized connectivity between geographically isolated demes. In this paper we implement this approach and discuss its implications for managing populations of the endangered Andros Island Rock Iguana, Cyclura cychlura cychlura. This iguana is endemic to Andros, a highly fragmented landmass of large islands and smaller cays. Field observations suggest that geographically isolated demes were panmictic due to high, inferred rates of gene flow. We expand on these observations using 16 polymorphic microsatellites to investigate the genetic …


Checklist Of Aquatic Oligochaetes Species In Tigris–Euphrates River Basin, Haifa J. Jaweir Sep 2014

Checklist Of Aquatic Oligochaetes Species In Tigris–Euphrates River Basin, Haifa J. Jaweir

Baghdad Science Journal

A total of 60 species of aquatic oligochaetes were identified in different sites within Tigris-Euphrates basin / Iraq, including River Tigris, River Euphrates, Southern marshes ( Al-Haweiza , Al-Hammar and Al-Chebaiesh ) , Shutt Al-Germa, and Shatt Al-Arab. In River Euphrates 39 species were identified, 40 species from River Tigris and 32 species from Shatt-Al-Arab and southern marshes.The identified species were classified as four species of Family Aeolosomatidae, 54 species of Naididae ( 31 Naidinae , 8 Pristininae and 15 Tubificid worms), one species of each of Lumbriculidae ( Lumbriculus variegates) and Lumbricidae ( Eiseiella tetraedra). Among Aeolosomatidae , Aelosoma …


Seasonal Study For Habitat Of Myriophyllum Spicatum L. In Al-Burgga Marsh, Hor Al-Hammar, Southern Iraq, Mohammed A. H. Al-Kenzawi Sep 2014

Seasonal Study For Habitat Of Myriophyllum Spicatum L. In Al-Burgga Marsh, Hor Al-Hammar, Southern Iraq, Mohammed A. H. Al-Kenzawi

Baghdad Science Journal

Myriophyllum spicatum distribution in Al-Burgga marsh, Hor Al-Hammar was described in relation to some of the physical-chemical properties for its habitat (water depth, light penetration, water temperature, water salinity, pH, dissolved oxygen, Ca+2, Mg+2, reactive NO2=, reactive NO3-1, and reactive PO4-3) during 2011, seasonally. CANOCO ordination program (CCA) was used to analyse the data. Its vegetation cover percentage was with its peak at summer, its value was 90 %, while the lowest value was 20 % in winter. Statistically, Positive relationships for WT, sal., Ca+2, Mg+2, reactive NO2=, reactive NO3-1, and reactive PO4-3 with the vegetation cover percentage were observed. …


Bioe 370.01: General Ecology, Erick P. Greene Sep 2014

Bioe 370.01: General Ecology, Erick P. Greene

University of Montana Course Syllabi

No abstract provided.


Pharyngeal And Cervical Cancer Incidences Significantly Correlate With Personal Uv Doses Among Whites In The United States, Dianne E. Godar, Rong Tang, Stephen Merrill Sep 2014

Pharyngeal And Cervical Cancer Incidences Significantly Correlate With Personal Uv Doses Among Whites In The United States, Dianne E. Godar, Rong Tang, Stephen Merrill

Mathematics, Statistics and Computer Science Faculty Research and Publications

Because we found UV-exposed oral tissue cells have reduced DNA repair and apoptotic cell death compared with skin tissue cells, we asked if a correlation existed between personal UV dose and the incidences of oral and pharyngeal cancer in the United States. We analyzed the International Agency for Research on Cancer's incidence data for oral and pharyngeal cancers by race (white and black) and sex using each state's average annual personal UV dose. We refer to our data as ‘white’ rather than ‘Caucasian,’ which is a specific subgroup of whites, and ‘black’ rather than African-American because blacks from other countries …


Baylisascaris Procyonis Prevalence And Impact In Raccoon (Procyon Lotor) Populations, Matthew Ingle Sep 2014

Baylisascaris Procyonis Prevalence And Impact In Raccoon (Procyon Lotor) Populations, Matthew Ingle

Loma Linda University Electronic Theses, Dissertations & Projects

Baylisascaris procyonis is a nematode parasite that infects the small intestines of raccoons (Procyon lotor). Raccoons are the definitive host for this parasite, which can have both an indirect and direct life cycle. In intermediate hosts, the parasite causes serious pathology resulting from larvae migrating through host tissue to the brain. Infection via exposure to B. procyonis eggs is fatal in over 90 vertebrate species that serve as intermediate hosts, including humans. The zoonotic potential of B. procyonis makes understanding factors that impact prevalence and pathology in raccoons important for management strategies. Alimentary canals from 226 raccoons trapped in nine …


Ensc 495.01: Field Study, Vicki J. Watson Sep 2014

Ensc 495.01: Field Study, Vicki J. Watson

University of Montana Course Syllabi

No abstract provided.


Factors Limiting The Spread Of The Protective Symbiont Hamiltonella Defensa In Aphis Craccivora Aphids, Hannah R. Dykstra, Stephanie R. Weldon, Adam J. Martinez, Jennifer A. White, Keith R. Hopper, George E. Heimpel, Mark K. Asplen, Kerry M. Oliver Sep 2014

Factors Limiting The Spread Of The Protective Symbiont Hamiltonella Defensa In Aphis Craccivora Aphids, Hannah R. Dykstra, Stephanie R. Weldon, Adam J. Martinez, Jennifer A. White, Keith R. Hopper, George E. Heimpel, Mark K. Asplen, Kerry M. Oliver

Entomology Faculty Publications

Many insects are associated with heritable symbionts that mediate ecological interactions, including host protection against natural enemies. The cowpea aphid, Aphis craccivora, is a polyphagous pest that harbors Hamiltonella defensa, which defends against parasitic wasps. Despite this protective benefit, this symbiont occurs only at intermediate frequencies in field populations. To identify factors constraining H. defensa invasion in Ap. craccivora, we estimated symbiont transmission rates, performed fitness assays, and measured infection dynamics in population cages to evaluate effects of infection. Similar to results with the pea aphid, Acyrthosiphon pisum, we found no consistent costs to infection using …