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Full-Text Articles in Life Sciences

First Record Of Paratelenomus Saccharalis (Dodd, 1914) (Hymenoptera: Scelionidae) A Natural Enemy Of The Invasive Species Brachyplatys Subaeneus (Westwood, 1837) (Heteroptera: Plataspidae) In Panama And The Neotropical Region, Jean Carlos Abrego, José A. Rivera, Carelos Vargas H., Annette Garrido, Julio Gutiérrez L., Miguel A. Osorio-Arenas, Pedro A. Arauz L., Luis A. Jaén, Rubén Collantes G., Alonso Santos-Murgas Oct 2023

First Record Of Paratelenomus Saccharalis (Dodd, 1914) (Hymenoptera: Scelionidae) A Natural Enemy Of The Invasive Species Brachyplatys Subaeneus (Westwood, 1837) (Heteroptera: Plataspidae) In Panama And The Neotropical Region, Jean Carlos Abrego, José A. Rivera, Carelos Vargas H., Annette Garrido, Julio Gutiérrez L., Miguel A. Osorio-Arenas, Pedro A. Arauz L., Luis A. Jaén, Rubén Collantes G., Alonso Santos-Murgas

Insecta Mundi

Paratelenomus saccharalis (Dodd) (Hymenoptera: Scelionidae) parasitizing Brachyplatys subaeneus (Westwood) eggs is reported for the first time for Panama. Brachyplatys subaeneus is an invasive species from Asia and is regarded as an important agricultural pest in the Americas.

The family Plataspidae (Hemiptera: Heteroptera) contains 66 genera and 606 species described (Rider et al. 2018), all distributed in the Old World, with the greatest diversity in Asia and Africa. Within this family, the genus Brachyplatys Boisduval, 1835 (Heteroptera: Plataspidae) has an Asian distribution with about 50 described species. The species Brachyplatys subaeneus (Westwood, 1837) is distributed in the Indo-Malay biogeographic region, being …


Elements Of Biocontrol Strategies For Pheretimoid Earthworms, Maryam Nouri-Aiin Jan 2022

Elements Of Biocontrol Strategies For Pheretimoid Earthworms, Maryam Nouri-Aiin

Graduate College Dissertations and Theses

Jumping worms (Megascolecidae) in the pheretimoid complex, have raisedconsiderable environmental concerns with conservationists, ecologists, policy makers, and the public. Their impacts on North American forests and high density is distinct from earthworms in other families. Most of the infested forests are near horticultural settings. Practicable options to manage their dispersal into forests do not exist. This dissertation examines the potential of an entomopathogenic fungus to control them in horticulture. It also investigates major barriers to managing their spread and studying their ecology including species identification, phenology, and genetic diversity. First, to discover the best time to apply biocontrol agents, I …


Evaluating The Use Of Barn Owl Nest Boxes For Rodent Pest Control In Winegrape Vineyards In Napa Valley, Ashley N. Hansen Jan 2022

Evaluating The Use Of Barn Owl Nest Boxes For Rodent Pest Control In Winegrape Vineyards In Napa Valley, Ashley N. Hansen

Cal Poly Humboldt theses and projects

Attracting natural enemies to farms to reduce pests has long been a part of integrated pest management for insects, but knowledge of the impact of raptors on rodents and other vertebrate pests is comparatively sparse. In this study, I compared rodent prey on winegrape vineyards in Napa California with and without occupied barn owl nest boxes. We collected data before the breeding season, when hunting pressure should be light, and again when adult owls were hunting actively to feed their chicks. I used the open-hole method to quantify an index of gopher activity, and Sherman live traps to estimate the …


Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels Jan 2022

Regenerative Agriculture Effects On Invertebrate And Bird Communities And Insect-Provided Ecosystem Services, Alex Michels

Electronic Theses and Dissertations

Conventional agricultural practices can have unintended consequences on the environment and wildlife. Insects and birds are declining at rapid rates around the world, and the current conventional agricultural paradigm is a major driver through habitat loss and the intensification of production. Invertebrates in agroecosystems provide services to both farmers and the rest of society. Regenerative systems may promote the functioning of an agroecosystem by influencing invertebrate abundance, diversity, and ecosystem services and mitigate bird and insect declines through conservation practices that increase soil health, reduce disturbances, and increase biological diversity. Here I address knowledge gaps of the effects of regenerative …


Host Plant Use, Phenology, And Biological Control Of The Brown Marmorated Stink Bug (Hemiptera: Pentatomidae; Halymorpha Halys) In Northern Utah, Mark Cody Holthouse Dec 2021

Host Plant Use, Phenology, And Biological Control Of The Brown Marmorated Stink Bug (Hemiptera: Pentatomidae; Halymorpha Halys) In Northern Utah, Mark Cody Holthouse

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The invasive brown marmorated stink bug, Halyomorpha halys (Stål), has become a significant agricultural and urban nuisance pest in North America, causing millions of dollars of damage to specialty fruit and vegetable crops over the past two decades. This pest uses over 170 host plant species in North America and is difficult to control with most conventional insecticides. Following the establishment of H. halys in Utah in 2012, this dissertation explores the plant host species, seasonal development, and biological control agents found in the unique climate conditions of the Intermountain West. Chapter II documents important plant species utilized by each …


Predator Defense And Host Selection Behavior Of Billbugs (Coleoptera: Dryophthoridae), Desireè M. Wickwar Aug 2021

Predator Defense And Host Selection Behavior Of Billbugs (Coleoptera: Dryophthoridae), Desireè M. Wickwar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Billbugs are a complex of weevils that feed on the roots of turfgrass, causing severe damage to the plants. These pests are traditionally managed with applications of insecticides. However, there is a need for non-chemical management tools. Here I investigate billbug behavior in relation to two potential avenues for more sustainable management: using resident predators to suppress billbugs (Chapter II) and selecting specific turfgrasses that resist billbug damage (Chapter III). In Chapter II, I investigate the effects of predator presence and cues associated with their presence on billbug behavior. Though resident predators contribute very little to billbug suppression through directly …


Understanding Patterns And Functional Impacts Of An Invasive Tree And Its Biological Control In A Riparian System, Annie L. Henry Jan 2021

Understanding Patterns And Functional Impacts Of An Invasive Tree And Its Biological Control In A Riparian System, Annie L. Henry

Electronic Theses and Dissertations

Invasive species have become an inextricable part of the landscape, particularly in riparian plant communities, and removal is often a key component of restoration programs. Biological control (biocontrol) is a method of removal that is often both efficient and effective. However, the impact of biocontrol on target species and indirect effects from invasive species removal can be hard to predict. While monitoring the impact of invasive species removal usually involves some species-based assessment such as changes in diversity, historically dominant species or native species, these strategies do not typically provide insight into the mechanisms underlying plant community response to removal. …


Ecology And Economic Impact Of The Invasive Brown Marmorated Stink Bug (Hemiptera: Pentatomidae; Halyomorpha Halys) In The Utah Agricultural Landscape, Zachary R. Schumm Aug 2020

Ecology And Economic Impact Of The Invasive Brown Marmorated Stink Bug (Hemiptera: Pentatomidae; Halyomorpha Halys) In The Utah Agricultural Landscape, Zachary R. Schumm

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The brown marmorated stink bug (BMSB) is a major insect pest that causes economic loss to a diversity of U.S. fruit and vegetable crops, and invades homes and human structures, causing nuisance issues for homeowners. This destructive insect causes millions of dollars of crop damage annually, and is difficult to manage due to its resistance to some common insecticides. BMSB is a relatively new pest to Utah, and its biology and ecology is not well known in the high elevation, arid Intermountain West region. In Chapter II, I explored the potential impact of BMSB to tart cherry, an unstudied crop …


Arcola Malloi (Pastrana), The Alligatorweed Stemborer, A New Synonym Of Macrorrhinia Endonephele (Hampson) (Lepidoptera: Pyralidae: Phycitinae), James E. Hayden, Jean-François Landry May 2020

Arcola Malloi (Pastrana), The Alligatorweed Stemborer, A New Synonym Of Macrorrhinia Endonephele (Hampson) (Lepidoptera: Pyralidae: Phycitinae), James E. Hayden, Jean-François Landry

Insecta Mundi

Arcola malloi (Pastrana, 1961) is a junior subjective synonym of Macrorrhinia endonephele (Hampson, 1918) syn. nov. (Lepidoptera: Pyralidae). The species is a biological control agent introduced in United States and Australia to control alligatorweed, Alternanthera philoxeroides (Mart.) Griseb. (Amaranthaceae). The synonymy is recognized by comparison of type specimens, genitalic dissections, and DNA COI barcoding. Vogtia Pastrana, 1961 syn. nov. and Arcola Shaffer, 1995 syn. nov. are synonymized with Macrorrhinia Ragonot, 1887. Macror­rhinia megajuxta (Neunzig and Goodson, 1992) comb. nov. is transferred from Ocala Hulst, 1892. Lectotypes are designated for Divitiaca ochrella Barnes and McDunnough, 1913, and Divitiaca simulella Barnes and …


An Evaluation Of Management Options For The Clover Root Curculio (Sitona Hispidulus), A Pest Of Alfalfa (Medicago Sativa) In The Intermountain West, Kaitlin A. Rim May 2020

An Evaluation Of Management Options For The Clover Root Curculio (Sitona Hispidulus), A Pest Of Alfalfa (Medicago Sativa) In The Intermountain West, Kaitlin A. Rim

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The clover root curculio (CRC) is an important forage pest throughout North America. Extensive larval feeding on host roots has been associated with reduced stand establishment, disruption of nutrient and water uptake, increased secondary plant pathogen infection, decreased winter plant survival, and reductions in forage quality and yield. Due to the hidden nature of larvae in the soil, CRC is often overlooked and integrated pest management programs are limited as there is a lack of management options. First, I surveyed northern Utah alfalfa for CRC natural enemies, particularly insect-attacking nematodes and fungi (entomopathogens) that could be used in biological control …


Pacific Northwest To New England: Exploring The Intersections Of Invasive Ecology, Forest Management, And Alternative Energy, Alexandra N. Neidermeier Jan 2020

Pacific Northwest To New England: Exploring The Intersections Of Invasive Ecology, Forest Management, And Alternative Energy, Alexandra N. Neidermeier

Graduate College Dissertations and Theses

Invasive species exact important ecologic, economic, and cultural tolls in forests. This research focused on the intersections of invasive ecology, forest management, and a forest commodity. Invasive ecology was explored through an assessment of two potential biological control agents of hemlock woolly adelgid. The two species of silver fly (Leucopis spp.) from the Pacific Northwest were first examined for temporal resource partitioning patterns. The niches of these species were then examined spatially by developing a species distribution model. Leucopis spp. exhibited sinusoidal patterns of daily emergence when examined over a 29-day period, with peak daily abundances that were inversely related. …


Korean Encyrtids (Hymenoptera: Encyrtidae) Associated With Scale Insects (Hemiptera: Coccomorpha), Soo-Jung Suh Jan 2019

Korean Encyrtids (Hymenoptera: Encyrtidae) Associated With Scale Insects (Hemiptera: Coccomorpha), Soo-Jung Suh

Insecta Mundi

Scale insects (Hemiptera: Coccomorpha) are sap-sucking plant parasites and economically important pests on agricultural and horticultural crops. Scale insects are often difficult to control since their body is protected by a wax cover. Parasitic wasps that live and develop in scale insects are important natural enemies and effective biological control agents of pest scale insects. Chalcid wasps of the family Encyrtidae (Hymenoptera: Chalcidoidea) comprise the largest group of parasitoids of scale insects, followed by the family Aphelinidae. Here, an updated list of all thirty-six species of encyrtids in twenty-three genera that have been identified or reported from South Korea is …


Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson Jan 2019

Diversifying Cornfields By Interseeding Cover Crops: Practical Implications And The Response Of Invertebrate Communities, Michael Bredeson

Electronic Theses and Dissertations

The lack of suitable habitat conditions for beneficial organisms in simplified agroecosystems leads to unstable invertebrate communities and overreliance on chemical control of herbivores. It is possible to manage pest populations without agrichemicals by manipulating farmland so that herbivores are impaired by plant-driven bottom-up and enemy-driven top-down antagonisms. Interseeding cover crops between established crop rows is a method used by farmers to improve habitat suitability for natural enemies and hinder host-finding, feeding and movement by herbivores. Here I address three important research gaps related to interseeding cover crops. A calcium carbonate seed coating, used to improve seed-broadcasting efficiency, was tested …


Impact Of Native Natural Enemies On Populations Of The Invasive Winter Moth (Operophtera Brumata L) In The Northeast United States, Hannah J. Broadley Oct 2018

Impact Of Native Natural Enemies On Populations Of The Invasive Winter Moth (Operophtera Brumata L) In The Northeast United States, Hannah J. Broadley

Doctoral Dissertations

Invasive insects increasingly affect forested landscapes and have important ecological and economic impacts. My dissertation focuses on population dynamics of winter moth (Operophtera brumata L.), an invasive pest in the northeastern United States. Native to Europe, this is the species’ fourth accidental introduction to North America. The Elkinton lab established the biological control agent Cyzenis albicans across the range of winter moth in the northeastern U.S. Prior research indicates that C. albicans’ ability to control winter moth likely depends on additional mortality from native natural enemies. My dissertation research evaluates the identity and role of natural enemies already …


Crop Pests And Predators Exhibit Inconsistent Responses To Surrounding Landscape Composition, Daniel S. Karp, Rebecca Chaplin-Kramer, Timothy D. Meehan, Emily A. Martin, Fabrice Declerck, Heather Grab, Claudio Gratton, Lauren Hunt, Ashley E. Larsen, Alejandra Martínez-Salinas, Megan E. O’Rourke, Adrien Rusch, Katja Poveda, Mattias Jonsson, Jay A. Rosenheim, Nancy A. Schellhorn, Teja Tscharntke, Stephen D. Wratten, Wei Zhang, Aaron L. Iverson, Lynn S. Adler, Matthias Albrecht, Audrey Alignier, Gina M. Angelella, Muhammad Zubair Anjum, Jacques Avelino, Péter Batáry, Johannes M. Baveco, Felix J. J. A. Bianchi, Klaus Birkhofer, David J. Gonthier Aug 2018

Crop Pests And Predators Exhibit Inconsistent Responses To Surrounding Landscape Composition, Daniel S. Karp, Rebecca Chaplin-Kramer, Timothy D. Meehan, Emily A. Martin, Fabrice Declerck, Heather Grab, Claudio Gratton, Lauren Hunt, Ashley E. Larsen, Alejandra Martínez-Salinas, Megan E. O’Rourke, Adrien Rusch, Katja Poveda, Mattias Jonsson, Jay A. Rosenheim, Nancy A. Schellhorn, Teja Tscharntke, Stephen D. Wratten, Wei Zhang, Aaron L. Iverson, Lynn S. Adler, Matthias Albrecht, Audrey Alignier, Gina M. Angelella, Muhammad Zubair Anjum, Jacques Avelino, Péter Batáry, Johannes M. Baveco, Felix J. J. A. Bianchi, Klaus Birkhofer, David J. Gonthier

Entomology Faculty Publications

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop …


Crop Pests And Predators Exhibit Inconsistent Responses To Surrounding Landscape Composition, Daniel S. Karp, Julie A. Peterson, 155 Other Co-Authors Aug 2018

Crop Pests And Predators Exhibit Inconsistent Responses To Surrounding Landscape Composition, Daniel S. Karp, Julie A. Peterson, 155 Other Co-Authors

Faculty Publications: Department of Entomology

The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop …


A New Colombian Pest Species Of The Genus Poecilocloeus Bruner (Orthoptera: Acrididae: Proctolabinae) On Coffee, With A Key To The Neotropical Species, Luis Miguel Constantino, Oscar J. Cadena-Castañeda, Juan Manuel Cardona Granda, Pablo Benavides M., Carmenza Góngora B. Jan 2018

A New Colombian Pest Species Of The Genus Poecilocloeus Bruner (Orthoptera: Acrididae: Proctolabinae) On Coffee, With A Key To The Neotropical Species, Luis Miguel Constantino, Oscar J. Cadena-Castañeda, Juan Manuel Cardona Granda, Pablo Benavides M., Carmenza Góngora B.

Insecta Mundi

A remarkable new species of Poecilocloeus (Orthoptera: Acrididae: Proctolabinae) found damaging coffee plantations in the Western Andes of Colombia is described and named P. coffeaphilus n. sp. This new species is part of a distinct and colorful group of Proctolabinae grasshoppers, with most species found at low altitudes in the rainforest of the Amazon basin. In contrast, the new species is found at elevations of 1600 to 1800 m in the canopy of dense cloud forests, in the southwestern part of the department of Antioquia (Western Cordillera, Colombian Andes). Information about the natural history, behavior, natural enemies and control strategies …


Assessing The Efficacy Of Two Species Of Silver Fly, Leucopis Argenticollis And L. Piniperda, As Biological Control Agents Of Hemlock Woolly Adelgid, Adelges Tsugae, Kyle Motley Jan 2017

Assessing The Efficacy Of Two Species Of Silver Fly, Leucopis Argenticollis And L. Piniperda, As Biological Control Agents Of Hemlock Woolly Adelgid, Adelges Tsugae, Kyle Motley

Graduate College Dissertations and Theses

Adelges tsugae Annand is a non-native invasive insect threatening the survival of eastern hemlock (Tsuga canadensis) and Carolina hemlock (T. caroliniana). A. tsugae is established in over half of the total range of eastern hemlock and the entire range of Carolina hemlock. Its continued spread, establishment and associated hemlock mortality make research into biological control of A. tsugae crucial. Field surveys of predators associated with A. tsugae in the Pacific Northwest identified a strong correlation between A. tsugae abundance with Laricobius nigrinus and two species of silver fly, Leucopis argenticollis and Leucopis piniperda. Flies in the genus Leucopis are known …


Evolution And Phylogeny Of The Parasitoid Subfamily Phasiinae (Diptera: Tachinidae), Jeremy Daniel Blaschke Aug 2015

Evolution And Phylogeny Of The Parasitoid Subfamily Phasiinae (Diptera: Tachinidae), Jeremy Daniel Blaschke

Doctoral Dissertations

The first molecular phylogenetic analysis of the agriculturally important parasitoid subfamily Phasiinae (Diptera: Tachinidae) is presented, estimated from 128 worldwide taxa (80 genera) and approximately 7.6 kilobases of nuclear data. Special emphasis is placed on taxa with controversial taxonomic placement. The resultant phylogenetic tree is used to reconstruct ancestral character states, trace the evolution of significant adaptive traits within the Tachinidae, and test hypotheses about the classification of Phasiinae. Subfamily placements of the taxa Eutherini, Epigrimyiini, Litophasia, Strongygastrini, and Parerigonini are confidently resolved, the former three within Dexiinae and the latter two within Phasiinae. Due to sparse molecular evidence, …


Flowers In Space Attacked By Aliens: Understanding The Spatial Ecology Behind The Devastating Damage By A Thistle Bud Weevil On Pitcher’S Thistle At Whitefish Dunes State Park, Wi, Zechariah D. Meunier Jun 2015

Flowers In Space Attacked By Aliens: Understanding The Spatial Ecology Behind The Devastating Damage By A Thistle Bud Weevil On Pitcher’S Thistle At Whitefish Dunes State Park, Wi, Zechariah D. Meunier

Lawrence University Honors Projects

One of the most threatened plants in the Great Lakes region is Pitcher’s thistle (Cirsium pitcheri), which inhabits sand dunes along the shorelines of Lakes Michigan, Huron, and Superior. In addition to risks from habitat loss and invasive species, C. pitcheri are imperiled by a thistle bud weevil (Larinus planus) that was originally distributed for biological control of nonnative thistles. During the summer of 2014, we empirically studied the devastating damage caused by L. planus on a population of C. pitcheri at Whitefish Dunes State Park, WI, to determine what factors influence the distribution and intensity …


A Checklist Of Natural Enemies Of Diaphorina Citri Kuwayama (Hemiptera: Liviidae) In The Department Of Valle Del Cauca, Colombia And The World, Takumasa Kondo, Guillermo González F., Catherine Tauber, Yoan Camilo Guzmán Sarmiento, Andrés Felipe Vinasco Mondragon, Dimitri Forero Jan 2015

A Checklist Of Natural Enemies Of Diaphorina Citri Kuwayama (Hemiptera: Liviidae) In The Department Of Valle Del Cauca, Colombia And The World, Takumasa Kondo, Guillermo González F., Catherine Tauber, Yoan Camilo Guzmán Sarmiento, Andrés Felipe Vinasco Mondragon, Dimitri Forero

Insecta Mundi

In recent years, populations of the Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), have increased in rural citrus orchards and urban backyard gardens. In order to find biological control options for D. citri, a search for natural enemies was conducted in the department of Valle del Cauca, Colombia. The collections were carried out in citrus orchards in rural areas and house gardens and street trees in urban areas. Natural enemies were collected from D. citri found on Citrus spp. and Murraya paniculata (L.) Jack (Rutaceae). A total of 16 species of natural enemies of D. citri distributed in …


Sources Of Variability In Agronomic Weed Seed Predation: Time, Space, Habitat, And Hyperpredation, Sonja K. Birthisel Dec 2013

Sources Of Variability In Agronomic Weed Seed Predation: Time, Space, Habitat, And Hyperpredation, Sonja K. Birthisel

Electronic Theses and Dissertations

Weed seed predation is an ecosystem service that benefits farmers by decreasing seedbank inputs, thereby reducing weed pressure in subsequent growing seasons. Seed predation can be considerable, but is highly variable. Sources of variability may include time, space, habitat, and trophic interactions such as hyperpredation. Two experiments were conducted to measure the impacts of these sources of variability on weed seed predation rates in Maine mixed vegetable agroecosystems.

Chapter One of this thesis describes a series of landscape-level field experiments conducted to quantify the effects of time, space, and habitat on seed predation rates. Seed assays, with and without vertebrate …


The Life History Of Larinus Minutus, A Biological Control Agent Of Invasive Knapweeds, And Its Dispersal From Release Sites In Arkansas, Adam M. Alford May 2013

The Life History Of Larinus Minutus, A Biological Control Agent Of Invasive Knapweeds, And Its Dispersal From Release Sites In Arkansas, Adam M. Alford

Graduate Theses and Dissertations

Larinus minutus Gyllenhal, a biological control agent of invasive knapweeds, has become established in several states and provinces since initial North American introduction in 1991. In order to reduce growing spotted knapweed populations in Northwest Arkansas, Larinus minutus (a biological control agent of spotted knapweed) was released annually from 2008-2011. Little is known about the larval development of this species, although the widespread use of this insect has provided research describing detailed host range and generalized life history. The speed and extent of the spread of this weevil from release sites following introduction have not been reported. This research described …


Interactions Between Pieris Oleracea And Pieris Rapae (Lepidoptera: Pieridae) Butterflies, And The Biological Control Agents Cotesia Glomerata And Cotesia Rubecula (Hymenoptera: Braconidae)., Megan V. Herlihy Jan 2013

Interactions Between Pieris Oleracea And Pieris Rapae (Lepidoptera: Pieridae) Butterflies, And The Biological Control Agents Cotesia Glomerata And Cotesia Rubecula (Hymenoptera: Braconidae)., Megan V. Herlihy

Masters Theses 1911 - February 2014

Pieris oleracea, formerly Pieries napi, was once a widespread pierid butterfly in New England until the introduction of a biological control agent, Cotesia glomerata. It has been suggested that C. glomerata is responsible for the range reduction of P. oleracea. There are been several introductions of a second more specialized biological control agent, Cotesia rubecula, to the United States since the 1960’s. My first goal was to determine the current distribution and status of P. rapae parasitoids and the effectiveness of C. rubecula as a biological control agent since its release. The findings of a survey …


The Strength Of Seeds And Their Destruction By Granivorous Insects, Jonathan G. Lundgren, Kurt A. Rosentrater Jun 2007

The Strength Of Seeds And Their Destruction By Granivorous Insects, Jonathan G. Lundgren, Kurt A. Rosentrater

Kurt A. Rosentrater

The influence of seed structure and strength on their destruction by granivores is central to understanding the dynamics of granivore-plant interactions. For up to nine seed species, the effects of seed size (cm3), mass (mg), density (mg/cm3) and coat strength (MPa) on the damage inflicted by three post-dispersal granivores (Harpalus pensylvanicus, Anisodactylus sanctaecrucis, and Gryllus pennsylvanicus) were evaluated. Seed destruction rates by G. pennsylvanicus were statistically unrelated to the size and toughness of the seeds. Seed densities significantly affected their destruction by A. sanctaecrucis and H. pensylvanicus, as did seed size, mass, and strength in H. pensylvanicus under choice conditions. …


Invasive Insect Abundance Varies Across The Biogeographic Distribution Of A Native Host Plant, Tatyana A. Rand, Svata M. Louda Jan 2006

Invasive Insect Abundance Varies Across The Biogeographic Distribution Of A Native Host Plant, Tatyana A. Rand, Svata M. Louda

Svata M. Louda Publications

Studies of biogeographic variation in species abundances are fundamental to understanding and predicting the impacts of invasive exotic species. We quantified the abundance of the introduced and now invasive biocontrol weevil, Rhinocyllus conicus, on a newly adopted native host plant, Cirsium canescens (Platte thistle), across the plant’s distributional range. We used regression and structural equation analyses to examine variation in weevil abundance at 92–108 sites over three years in relation to variation in abiotic and biotic parameters hypothesized to be important in insect or plant dynamics and distribution. We found that R. conicus now occurs throughout the majority of …


Biological Notes On Ground-Nesting Digger Wasps From Western Nebraska, Robert W. Matthews, Janice R. Matthews Jun 2005

Biological Notes On Ground-Nesting Digger Wasps From Western Nebraska, Robert W. Matthews, Janice R. Matthews

The Prairie Naturalist

Nine species of sphecid wasps nesting in sparsely vegetated sandy soils near Ogallala, Keith County, Nebraska were studied during June 2003. The first records of the nest and prey of Cerceris clypeata gnarina Banks and Tachysphex williamsi R. Bohart are presented. Two species of weevils, Baris striata Say and B. subsimilis Casey, were prey of C. clypeata gnarina, with 12 to 22 individuals stocked per cell. Because B. subsimilis is a biological control agent for thistle, this finding is a caution to researchers not to ignore the potential impact of predatory wasps on the community. The single nest of T …


Local- Vs. Landscape-Scale Indirect Effects Of An Invasive Weed On Native Plants, Tatyana A. Rand, F. Leland Russell, Svata M. Louda Jan 2004

Local- Vs. Landscape-Scale Indirect Effects Of An Invasive Weed On Native Plants, Tatyana A. Rand, F. Leland Russell, Svata M. Louda

Svata M. Louda Publications

Insect-mediated indirect interactions between native plant species recently have been shown to be important determinants of plant performance in a number of ecological communities. However, the potential indirect effects of exotic plant invasion on native plant species are not well understood. We examined whether the presence or proximity of the targeted exotic weed, musk thistle, influences the magnitude of attack on native thistles by the introduced biological control, flowerhead weevil. At the local scale, we quantified weevil egg densities on heads of the native wavyleaf thistle growing at different distances (0 to 100 m) from patches of the exotic thistle. …


Evidence For Natural Biological Control: Insects Decrease Survival And Growth Of A Native Thistle, John A. Guretzky, Svata M. Louda Jan 1997

Evidence For Natural Biological Control: Insects Decrease Survival And Growth Of A Native Thistle, John A. Guretzky, Svata M. Louda

Svata M. Louda Publications

Native thistles, in contrast to exotic species, are seldom noxious weeds. In this study, we evaluated one hypothesis for this difference: that the growth and fitness of native thistles are limited by natural enemies. Specifically, we tested the effect of insect foliage feeding on the survival and growth of large and small rosettes of tall thistle, Cirsium altissimum, using an insecticide exclusion experiment. Large juveniles were proportionally more damaged than were small ones. Insecticide reduced insect feeding, including overall intensity of plant damage and area removed or damaged on each of the two longest leaves, compared to controls treated only …