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Automated Trichome Counting In Soybean Using Advanced Image‐Processing Techniques, Seyed Vahid Mirnezami, Therin Young, Teshale Assefa, Shelby Prichard, Koushik Nagasubramanian, Kulbir Sandhu, Soumik Sarkar, Sriram Sundararajan, Matthew E. O'Neal, Baskar Ganapathysubramanian, Arti Singh Jul 2020

Automated Trichome Counting In Soybean Using Advanced Image‐Processing Techniques, Seyed Vahid Mirnezami, Therin Young, Teshale Assefa, Shelby Prichard, Koushik Nagasubramanian, Kulbir Sandhu, Soumik Sarkar, Sriram Sundararajan, Matthew E. O'Neal, Baskar Ganapathysubramanian, Arti Singh

Mechanical Engineering Publications

Premise Trichomes are hair‐like appendages extending from the plant epidermis. They serve many important biotic roles, including interference with herbivore movement. Characterizing the number, density, and distribution of trichomes can provide valuable insights on plant response to insect infestation and define the extent of plant defense capability. Automated trichome counting would speed up this research but poses several challenges, primarily because of the variability in coloration and the high occlusion of the trichomes.

Methods and Results We developed a simplified method for image processing for automated and semi‐automated trichome counting. We illustrate this process using 30 leaves from ...


Targeted Suppression Of Soybean Bag6‐Induced Cell Death In Yeast By Soybean Cyst Nematode Effectors, Jianying Wang, Greg Yeckel, Pramod K. Kandoth, Lakmini Wasala, Richard S. Hussey, Eric L. Davis, Thomas J. Baum, Melissa G. Mitchum Jan 2020

Targeted Suppression Of Soybean Bag6‐Induced Cell Death In Yeast By Soybean Cyst Nematode Effectors, Jianying Wang, Greg Yeckel, Pramod K. Kandoth, Lakmini Wasala, Richard S. Hussey, Eric L. Davis, Thomas J. Baum, Melissa G. Mitchum

Plant Pathology and Microbiology Publications

While numerous effectors that suppress plant immunity have been identified from bacteria, fungi, and oomycete pathogens, relatively little is known for nematode effectors. Several dozen effectors have been reported from the soybean cyst nematode (SCN). Previous studies suggest that a hypersensitive response‐like programmed cell death is triggered at nematode feeding sites in soybean during an incompatible interaction. However, virulent SCN populations overcome this incompatibility using unknown mechanisms. A soybean BAG6 (Bcl‐2 associated anthanogene 6) gene previously reported by us to be highly up‐regulated in degenerating feeding sites induced by SCN in a resistant soybean line was attenuated ...


Screening Soybean Cyst Nematode Effectors For Their Ability To Suppress Plant Immunity, Gennady Pogorelko, Jianying Wang, Parijat S. Juvale, Melissa G. Mitchum, Thomas J. Baum Jan 2020

Screening Soybean Cyst Nematode Effectors For Their Ability To Suppress Plant Immunity, Gennady Pogorelko, Jianying Wang, Parijat S. Juvale, Melissa G. Mitchum, Thomas J. Baum

Plant Pathology and Microbiology Publications

The soybean cyst nematode (SCN), Heterodera glycines , is one of the most destructive pathogens of soybeans. SCN is an obligate and sedentary parasite that transforms host plant root cells into an elaborate permanent feeding site, a syncytium. Formation and maintenance of a viable syncytium is an absolute requirement for nematode growth and reproduction. In turn, sensing pathogen attack, plants activate defence responses and may trigger programmed cell death at the sites of infection. For successful parasitism, H. glycines must suppress these host defence responses to establish and maintain viable syncytia. Similar to other pathogens, H. glycines engages in these molecular ...


Spatial Patterns And Sequential Sampling Plans For Estimating Densities Of Stink Bugs (Hemiptera: Pentatomidae) In Soybean In The North Central Region Of The United States, Daniela T. Pezzini, Christina D. Difonzo, Deborah L. Finke, Thomas Hunt, Janet J. Knodel, Christian H. Krupke, Brian P. Mccornack, Andrew P. Michel, Roger D. Moon, Christopher R. Philips, Adam J. Varenhorst, Robert Wright, Robert Koch Apr 2019

Spatial Patterns And Sequential Sampling Plans For Estimating Densities Of Stink Bugs (Hemiptera: Pentatomidae) In Soybean In The North Central Region Of The United States, Daniela T. Pezzini, Christina D. Difonzo, Deborah L. Finke, Thomas Hunt, Janet J. Knodel, Christian H. Krupke, Brian P. Mccornack, Andrew P. Michel, Roger D. Moon, Christopher R. Philips, Adam J. Varenhorst, Robert Wright, Robert Koch

Faculty Publications: Department of Entomology

Stink bugs are an emerging threat to soybean (Fabales: Fabaceae) in the North Central Region of the United States. Consequently, region-specific scouting recommendations for stink bugs are needed. The aim of this study was to characterize the spatial pattern and to develop sampling plans to estimate stink bug population density in soybean fields. In 2016 and 2017, 125 fields distributed across nine states were sampled using sweep nets. Regression analyses were used to determine the effects of stink bug species [Chinavia hilaris (Say) (Hemiptera: Pentatomidae) and Euschistus spp. (Hemiptera: Pentatomidae)], life stages (nymphs and adults), and field locations (edge and ...


What Are The Consequences Of Resistance? Exploring The Impacts Of Insecticide And Host-Plant Resistance For Insect Pest Management, Ashley Nicole Dean Jan 2019

What Are The Consequences Of Resistance? Exploring The Impacts Of Insecticide And Host-Plant Resistance For Insect Pest Management, Ashley Nicole Dean

Graduate Theses and Dissertations

Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), has been a prominent insect pest in the northcentral region since 2000. Insecticides are the primary management tactic for this pest, but some populations of soybean aphid resistant to pyrethroid insecticides have been reported since 2015. This increases the impact of soybean aphid on soybean, Glycine max (L.) Merr (Fabales: Fabaceae), production, which is already challenged by higher input costs, declining market value, and unpredictable weather. Soybean aphid-resistant varieties are available to farmers but limited to genetic backgrounds that exclude herbicide-tolerance. This is a significant barrier to adoption since farmers rely on herbicide-tolerant ...


Management Of Insecticide-Resistant Soybean Aphids In The Upper Midwest Of The United States, Robert L. Koch, Erin W. Hodgson, Janet J. Knodel, Adam J. Varenhorst, Bruce D. Potter Jan 2018

Management Of Insecticide-Resistant Soybean Aphids In The Upper Midwest Of The United States, Robert L. Koch, Erin W. Hodgson, Janet J. Knodel, Adam J. Varenhorst, Bruce D. Potter

Entomology Publications

Since the first observation of soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in North America in 2000, it has become the most economically damaging insect of soybean in the Upper Midwest of the United States. For the last 17 yr, soybean aphid management has relied almost entirely on the use of foliar-applied broad-spectrum insecticides. However, in 2015 in Minnesota, failures of foliar-applied pyrethroid insecticides were reported and pyrethroid resistance was confirmed with laboratory bioassays using lambda-cyhalothrin and bifenthrin. In 2016 and 2017, further reports of failures of pyrethroid insecticides and/or laboratory confirmation of resistance occurred in Iowa, North Dakota ...


Insecticidal Seed And In-Furrow Treatment Recommendations For Soybean And Sunflower, Brady Hauswedell Jan 2018

Insecticidal Seed And In-Furrow Treatment Recommendations For Soybean And Sunflower, Brady Hauswedell

Electronic Theses and Dissertations

Throughout the 2016 and 2017 growing season, field research experiments were replicated across South Dakota. Many times seed treatments are used prophylactic, which is neither good for the producers or the environment. Producers will be able to reduce production costs, if they only use a seed treatment when necessary. The purpose of the first experiment was to determine the effects of seed treatments in combination with planting date and seeding rate on soybean yield. To determine the effects, two years of field data from four eastern South Dakota locations were compared. Within each year and location we compared two planting ...


Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black Dec 2017

Horizontal Transmission Of Helicoverpa Armigera Nucleopolyhedrovirus (Hearnpv) In Soybean Fields Infested With Helicoverpa Zea (Boddie), Joseph Lee Black

Theses and Dissertations

Helicoverpa armigera Nucleopolyhedrovirus (HearNPV) is a commercially available viral biopesticide that targets Heliothines, including Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), the most damaging pest of soybean (Glycine max (L.) Merrill) in the Mid-South. Previous formulations of HearNPV have been well studied; however, no research has been published on current formulations. The first objective of this thesis was to assess the rate of horizontal transmission of HearNPV in a soybean field infested with H. zea when HearNPV was applied as a bio-insecticide, and to identify arthropods that are important obligate carriers in dissemination. HearNPV spread 200 feet in 3 fields, and was ...


Incorporation Of Biorationals And Trap Crop For Stink Bug Management In Soybeans, Kukuh Hernowo Nov 2017

Incorporation Of Biorationals And Trap Crop For Stink Bug Management In Soybeans, Kukuh Hernowo

LSU Doctoral Dissertations

Stink bugs are one of the most important seed sucking pests impacting soybean production in Louisiana. Exploration of chemicals that exhibit attraction or repellent activities toward this major pest would be beneficial to develop a push-pull strategy against this pest complex. Spinosad and neem are two commercially available natural insecticides that were claimed to have attractant and repellent activities against stink bugs. To test the potential of these chemicals, a series of experiments was conducted to investigate the olfactory, tactile, feeding, and oviposition preference of stink bugs toward different commercial spinosad products and neem. Additionally, two years of field experiments ...


Effects Of Elicitor Induced Host Plant Resistance On Lepidopteran Insecticide Efficacy, Abigail Cox Aug 2017

Effects Of Elicitor Induced Host Plant Resistance On Lepidopteran Insecticide Efficacy, Abigail Cox

LSU Master's Theses

Soybean looper (SBL), Chrysodeixis includens (Walker), is an important defoliating Lepidopteran pest of southern U.S. soybean and utilizes other agronomic crops and weeds as hosts. With increasing resistance to insecticides, alternative control strategies such as induced host plant resistance were evaluated against SBL. Jasmonic acid (JA) is an elicitor of host plant resistance, and was selected to determine its fit in an IPM plan for SBL. JA was applied to the top of meridic SBL diet and fed to SBL; no effects were found. JA applied as an exogenous elicitor to cotton, sweet potato, okra, cowpea, and soybean did ...


Ecological Risks Of The Conventional Insecticide/Fungicide Seed Treatment Mixture Of Thiamethoxam And Mefenoxam In Soybean On Beneficial Insects, Carolina Camargo Apr 2016

Ecological Risks Of The Conventional Insecticide/Fungicide Seed Treatment Mixture Of Thiamethoxam And Mefenoxam In Soybean On Beneficial Insects, Carolina Camargo

Dissertations and Student Research in Entomology

The impact of neonicotinoid seed treatments on beneficial insects has been a controversial topic during the last years. While neonicotinoids are usually used as mixtures with systemic fungicides, few studies have examined the impact of the mixtures on beneficial insects. Pesticide mixtures can have synergistic, additive, or antagonistic effects on the toxicity of neonicotinoids on non-target species.

Thiamethoxam with mefenoxam is the most used neonicotinoid insecticide/fungicide mixture applied to soybean. Based on the systemic nature of thiamethoxam and mefenoxam, residues of this insecticide/fungicide mixture can be present in soybean vegetative and floral tissue with potential impacts to beneficial ...


Reduced Fitness Of Virulent Aphis Glycines (Hemiptera: Aphididae) Biotypes May Influence The Longevity Of Resistance Genes In Soybean, Adam J. Varenhorst, Michael T. Mccarville, Matthew E. O'Neal Sep 2015

Reduced Fitness Of Virulent Aphis Glycines (Hemiptera: Aphididae) Biotypes May Influence The Longevity Of Resistance Genes In Soybean, Adam J. Varenhorst, Michael T. Mccarville, Matthew E. O'Neal

Entomology Publications

Sustainable use of insect resistance in crops require insect resistance management plans that may include a refuge to limit the spread of virulence to this resistance. However, without a loss of fitness associated with virulence, a refuge may not prevent virulence from becoming fixed within a population of parthenogenetically reproducing insects like aphids. Aphid-resistance in soybeans (i.e., Rag genes) prevent outbreaks of soybean aphid (Aphis glycines), yet four biotypes defined by their capacity to survive on aphid-resistant soybeans (e.g., biotype-2 survives on Rag1 soybean) are found in North America. Although fitness costs are reported for biotype-3 on aphid ...


Investigation Of Reduced Agent And Area Treatments For Aphis Glycines Management And Its Effects On Key Predators, Jenny S. Enchayan Aug 2015

Investigation Of Reduced Agent And Area Treatments For Aphis Glycines Management And Its Effects On Key Predators, Jenny S. Enchayan

Dissertations and Student Research in Entomology

Soybeans are an abundant and valued agricultural crop in Nebraska and other parts of the world. Significant soybean aphid, Aphis glycines Matsumura, mortality has been observed in research plots adjacent to soybeans treated with chlorpyrifos in late July through August. The objectives of the study were to determine the efficacy of the chlorpyrifos vapor effect on A. glycines in adjacent untreated areas and assess the impact of the vapor effect on key biological control agents. Observation of A. glycines populations and sweep net samples for other arthropod species, including Oruis insidiosus, began weekly in mid to late July. When aphid ...


Survey Of Soybean Insect Pollinators: Community Identification And Sampling Method Analysis, K. A. Gill, M. E. O'Neal Jun 2015

Survey Of Soybean Insect Pollinators: Community Identification And Sampling Method Analysis, K. A. Gill, M. E. O'Neal

Entomology Publications

Soybean, Glycine max (L.) Merrill, flowers can be a source of nectar and pollen for honey bees, Apis mellifera L. (Hymenoptera: Apidae), wild social and solitary bees (Hymenoptera: Apoidea), and flower-visiting flies (Diptera). Our objectives were to describe the pollinator community in soybean fields, determine which sampling method is most appropriate for characterizing their abundance and diversity, and gain insight into which pollinator taxa may contact soybean pollen. We compared modified pan traps (i.e., bee bowls), yellow sticky traps, and sweep nets for trapping pollinators in Iowa soybean fields when soybeans were blooming (i.e., reproductive stages R1–R6 ...


Transcriptional Responses Of Tolerant And Susceptible Soybeans To Soybean Aphid (Aphis Glycines Matsumura) Herbivory, Travis J. Prochaska, Teresa Donze-Reiner, L. Marchi-Werle, N. A. Palmer, Thomas E. Hunt, Gautam Sarath, Tiffany Heng-Moss Jan 2015

Transcriptional Responses Of Tolerant And Susceptible Soybeans To Soybean Aphid (Aphis Glycines Matsumura) Herbivory, Travis J. Prochaska, Teresa Donze-Reiner, L. Marchi-Werle, N. A. Palmer, Thomas E. Hunt, Gautam Sarath, Tiffany Heng-Moss

Faculty Publications: Department of Entomology

The soybean aphid, Aphis glycines Matsumura, was introduced in 2000 to North America and has become one of the most significant pests to soybean, Glycine max (L.) Merrill, production. Possible solutions to this problem are the use of resistant plants and the understanding of the genes involved in plant resistance. In this study, we sought to better understand the genes involved in the tolerance response of soybean plants to the soybean aphid, utilizing tolerant (KS4202) and susceptible (K-03-4686) plants. Studies were conducted under greenhouse conditions. Leaf samples of both tolerant and susceptible plants were collected at day 5 and day ...


Herbivore Response To Soybean Under Differing Induction Methods, John L. Dryburgh Jan 2015

Herbivore Response To Soybean Under Differing Induction Methods, John L. Dryburgh

LSU Master's Theses

Plants are attacked by a variety of herbivore feeding guilds and respond with specific responses to specific attacks, which may be localized or systemic. How a plant defends against one feeding guild may alter the plant’s response against a different feeding guild. A better understanding of these interactions will allow for the development of refined pest management programs. One situation in which this may occur is in interactions between chewing and piercing/sucking herbivores, such as aphids. Aphids are important crop pests primarily due to their ability to transmit viruses, the efficacy of which can be affected by plant ...


Impact And Management Of Megacopta Cribraria (Hemiptera: Plataspidae), Nicholas Seiter May 2014

Impact And Management Of Megacopta Cribraria (Hemiptera: Plataspidae), Nicholas Seiter

All Dissertations

Megacopta cribraria (F.) (Hemiptera: Plataspidae), known informally as the kudzu bug or bean plataspid, was found in Georgia in 2009 and has since spread rapidly throughout the southeastern United States. A known feeder on soybean, Glycine max (L.) Merrill, in its native Asian range, M. cribraria has been commonly encountered in soybean fields in the southeastern United States since its first detection in the crop in Georgia and South Carolina during 2010. In addition, its overwintering behavior sometimes results in nuisance infestations in homes. The primary objectives of this research were to determine the potential impacts of M. cribraria on ...


Aboveground Feeding By Soybean Aphid, Aphis Glycines, Affects Soybean Cyst Nematode, Heterodera Glycines, Reproduction Belowground, Michael T. Mccarville, David H. Soh, Gregory L. Tylka, Matthew E. O'Neal Jan 2014

Aboveground Feeding By Soybean Aphid, Aphis Glycines, Affects Soybean Cyst Nematode, Heterodera Glycines, Reproduction Belowground, Michael T. Mccarville, David H. Soh, Gregory L. Tylka, Matthew E. O'Neal

Entomology Publications

Heterodera glycines is a cyst nematode that causes significant lost soybean yield in the U.S. Recent studies observed the aphid Aphis glycines and H. glycines interacting via their shared host, soybean, Glycine max. A greenhouse experiment was conducted to discern the effect ofA. glycines feeding on H. glycines reproduction. An H. glycines-susceptible cultivar, Kenwood 94, and a resistant cultivar, Dekalb 27–52, were grown in H. glycines-infested soil for 30 and 60 d. Ten days after planting, plants were infested with either zero, five, or ten aphids. At 30 and 60 d, the number of H ...


Insect Pollinators In Corn And Soybean Agricultural Fields, Michael Joseph Wheelock Jan 2014

Insect Pollinators In Corn And Soybean Agricultural Fields, Michael Joseph Wheelock

Graduate Theses and Dissertations

Iowa's landscape is dominated by row crop agriculture with the majority of acres being in corn and soybean production, and as a result is spatially uniform and functionally homogenized. In landscapes dominated by agriculture, such as those found in Iowa, the availability of mass flowering crop species show strong positive effects on the density of generalist, native pollinators. While soybean, a self-pollinated plant, and corn, a wind pollinated plant, do not require physical pollination for fruit production, they can be a source of nectar and/or pollen for insect pollinators. The first objective is to develop methodology to accurately ...


Effects Of Induced Plant Resistance And Potassium Fertilization Rates On Soybean Looper (Chrysodeixis Includens) Development In Soybean, Xuan Chen Jan 2014

Effects Of Induced Plant Resistance And Potassium Fertilization Rates On Soybean Looper (Chrysodeixis Includens) Development In Soybean, Xuan Chen

LSU Master's Theses

Soybean looper, Chrysodeixis includens (Walker), is one of the most destructive pests of soybean in the southern U.S. It is highly resistant to most insecticides. Induced host plant resistance and cultural control are sought as alternative control tactics. In this study, effects of induced resistance by exogenous application of elicitors were estimated on soybean looper development in soybean. Three different known elicitors of SAR (systemic acquired resistance), Actigard 50WG (acibenzolar-S-methyl), Regalia (extract of Reynoutria sachalinensis) and methyl jasmonate (MeJA), were applied to soybean plants at R2 and R5 stages to determine if these chemicals could induce plant resistance and ...


Effects Of Rag1 On The Preference And Performance Of Soybean Defoliators, Robert F. Bruner, Erin W. Hodgson, Aaron J. Gassmann Dec 2013

Effects Of Rag1 On The Preference And Performance Of Soybean Defoliators, Robert F. Bruner, Erin W. Hodgson, Aaron J. Gassmann

Entomology Publications

The Rag1 gene confers antibiotic resistance to soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and in 2010, varieties expressing Rag1 were released for commercial use in the United States. We do not know how Rag1 varieties will influence the broader community of defoliating insects that inhabit soybean fields. In 2010 and 2011, the preference and performance of pest insects that defoliate soybeans [Glycines max (L.) Merr] were tested using Rag1 and aphidsusceptible varieties. Three coleopterans and four lepidopterans were used: northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae); southern corn rootworm, Diabrotica undecimpunctata howardi Barber (Coleoptera: Chrysomelidae); bean leaf beetle, Ceratoma trifurcata ...


Investigating The Tolerance Response Of Early Vegetative Stage Soybeans To Aphis Glycines Matsumura, Lia Da Silva Marchi Nov 2012

Investigating The Tolerance Response Of Early Vegetative Stage Soybeans To Aphis Glycines Matsumura, Lia Da Silva Marchi

Dissertations and Student Research in Entomology

The objectives of this research were to evaluate the impact of soybean aphid (Aphis glycines Matsumura) feeding on the yield response of V1, V3, and R1 KS4202 soybean plants and examine the effect of soybean aphid feeding on peroxidase activity in V1 and V3 KS4202 plants. KS4202 plants infested during the early vegetative stages (VC, VE and V1) were identified as highly susceptible based upon plant damage and stunting of the plants. In contrast, V3, V4, and V5 stage KS4202 soybeans were classified as moderately resistant. In the yield response study, V1, V3 and R1 plants had aphid numbers that ...


Measuring The Benefit Of Biological Control For Single Gene And Pyramided Host Plant Resistance For Aphis Glycines (Hemiptera: Aphididae) Management, Michael T. Mccarville, Matthew E. O'Neal Oct 2012

Measuring The Benefit Of Biological Control For Single Gene And Pyramided Host Plant Resistance For Aphis Glycines (Hemiptera: Aphididae) Management, Michael T. Mccarville, Matthew E. O'Neal

Entomology Publications

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is an economically important pest in the north central United States. In the state of Iowa, economically damaging populations occurred in seven of 11 growing seasons from 2001 to 2011. The high frequency and economic impact of the soybean aphid makes it an ideal candidate for management by using host plant resistance. We compared an aphid-susceptible line to near-isolines that contain Rag1 and Rag2, both alone and pyramided together, to suppress aphid populations and protect yield. Each of four near-isolines, were artificially infested with aphids and grown in small plots in which ...


Insecticidal Control Of Bemisia Tabaci (Hemiptera: Aleyrodidae) Transmitting Carlavirus On Soybeans And Detection Of The Virus In Alternate Hosts, Difabachew K. Belay, Randy M. Huckaba, Axel M. Ramirez, Jose C. V. Rodrigues, John E. Foster May 2012

Insecticidal Control Of Bemisia Tabaci (Hemiptera: Aleyrodidae) Transmitting Carlavirus On Soybeans And Detection Of The Virus In Alternate Hosts, Difabachew K. Belay, Randy M. Huckaba, Axel M. Ramirez, Jose C. V. Rodrigues, John E. Foster

Faculty Publications: Department of Entomology

A Carlavirus transmitted by Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important disease of soybean nurseries in Puerto Rico causing substantial germplasm losses. Insecticide bioassay experiments were conducted at Dow AgroSciences (DAS) Research Station, Santa Isabel, Puerto Rico, either by spraying insecticides on B. tabaci infested soybean leaves or introducing B. tabaci adults onto insecticide-sprayed soybean leaves. Moreover, host plants were surveyed to detect the virus in overwintering hosts that serve as a source of inoculums. The direct spray experiment showed that Nuprid 2F (Imidacloprid), Capture 2 EC (Bifenthrin), Thionex (Endosulfan), Lannate LV (Methomyl), and Dimethoate gave good level (> 80 ...


Cross-Resistance And Resistance Longevity As Induced By Bean Leaf Beetle, Cerotoma Trifurcata And Soybean Looper, Pseudoplusia Includens Herbivory On Soybean, P. Srinivas, Stephen D. Danielson, C. Michael Smith, John E. Foster Mar 2012

Cross-Resistance And Resistance Longevity As Induced By Bean Leaf Beetle, Cerotoma Trifurcata And Soybean Looper, Pseudoplusia Includens Herbivory On Soybean, P. Srinivas, Stephen D. Danielson, C. Michael Smith, John E. Foster

John E. Foster

Cross-resistance, and longevity of resistance, induced by the bean leaf beetle, Cerotoma trifurcata, was studied IN the soybean PI 227687 that exhibited induced response in earlier studies. Bean leaf beetle adults and soybean looper, Pseudoplusia includens, larvae were used to induce resistance and to determine beetle feeding preference. Beetles were collected from soybean fields 2 to 5 days prior to the feeding preference test. The level of cross-resistance induced by soybean looper herbivory to subsequent bean leaf beetle feeding was higher when compared to cross-resistance induced by bean leaf beetle herbivory against subsequent feeding by soybean looper. Further, herbivory by ...


Bean Leaf Beetle (Coleoptera: Chrysomelidae) And Bean Pod Mottle Virus In Soybean: Biology, Ecology, And Management, Buyung A. R. Hadi, Jeffrey D. Bradshaw, Marlin E. Rice, John J. Hill Mar 2012

Bean Leaf Beetle (Coleoptera: Chrysomelidae) And Bean Pod Mottle Virus In Soybean: Biology, Ecology, And Management, Buyung A. R. Hadi, Jeffrey D. Bradshaw, Marlin E. Rice, John J. Hill

Faculty Publications: Department of Entomology

Bean leaf beetle, Cerotoma trifurcata (Förster), is a pest of soybean found in many production areas in the United States. The bean leaf beetle larvae feed on soybean root nodules, whereas the adults feed on the above ground parts of soybean such as cotyledon, leaves, and pods. Bean leaf beetle is also a very efficient vector of Bean pod mottle virus, a widespread virus of soybean in the south and southeastern United States with recent expansion into the north central region of the country. This article summarizes bean leaf beetle biology, ecology, and its impact on soybean production in the ...


Soybean Aphid (Hemiptera: Aphididae) Development On Soybean With Rag1 Alone, Rag2 Alone, And Both Genes Combined, Shaylyn Lena Wiarda, Walter R. Fehr, Matthew E. O'Neal Jan 2012

Soybean Aphid (Hemiptera: Aphididae) Development On Soybean With Rag1 Alone, Rag2 Alone, And Both Genes Combined, Shaylyn Lena Wiarda, Walter R. Fehr, Matthew E. O'Neal

Entomology Publications

Aphis glycines Matsumura (Hemiptera: Aphididae) can reduce the yield of aphidsusceptible soybean (Glycine max (L.) Merrill) cultivars. The Rag1 and Rag2 genes confer resistance to some biotypes of A. glycines. These genes individually can limit population growth of A. glycines and prevent yield loss. The impact of these genes when combined is not known. We compared the development of A. glycines on soybean with Rag1 alone (R1/S2), Rag2 alone (S1/R2), both genes combined (R1/R2), or neither gene (S1/S2). In addition, we determined the impact of different levels of aphid infestation on seed yield. The genotypes were ...


Characterization Of The Tolerance Response In The Soybean Ks4202 To Aphis Glycines Matsumura, Travis J. Prochaska Dec 2011

Characterization Of The Tolerance Response In The Soybean Ks4202 To Aphis Glycines Matsumura, Travis J. Prochaska

Dissertations and Student Research in Entomology

Since the introduction of the soybean aphid, Aphis glycines Matsumura, to the soybean growing regions of the United States, the soybean aphid has caused considerable economic damage and yield loss to soybean growers. The objectives of this research were to evaluate selected genotypes for resistance to the soybean aphid and characterize transcriptional changes in response to aphid feeding to better understand the underlying tolerant mechanism(s) in KS4202 and genes contributing to its tolerance response. A field study (2009) was conducted to evaluate selected soybean genotypes during their reproductive stages for resistance to A. glycines. The economic injury level (EIL ...


Distribution Of Two Rotation-Resistant Corn Pests In Eastern Iowa And Effects Of Soybean Varieties On Biology Of Diabrotica Virgifera Virgifera, Michael Wilson Dunbar Jan 2011

Distribution Of Two Rotation-Resistant Corn Pests In Eastern Iowa And Effects Of Soybean Varieties On Biology Of Diabrotica Virgifera Virgifera, Michael Wilson Dunbar

Graduate Theses and Dissertations

The western corn rootworm Diabrotica virgifera virgifera LeConte (WCR) and the northern corn rootworm Diabrotica barberi Smith & Lawrence (NCR) are two significant insect pests of corn in North America. Both species have adapted to crop rotation in the Midwest, NCR through extended diapause and WCR by ovipositing in alternative crops. We conducted surveys during 2008 and 2009 to collect data on the presence of rotation-resistant NCR and WCR. Data were collected by placing Pherocon AM sticky traps in soybean and corn fields and by placing emergence cages in corn fields. Rotation-resistant WCR was most common in the northeastern and east-central ...


What Is The Economic Threshold Of Soybean Aphids (Hemiptera: Aphididae) In Enemy-Free Space?, Michael T. Mccarville, Charles Kanobe, Gustavo C. Macintosh, Matthew E. O'Neal Jan 2011

What Is The Economic Threshold Of Soybean Aphids (Hemiptera: Aphididae) In Enemy-Free Space?, Michael T. Mccarville, Charles Kanobe, Gustavo C. Macintosh, Matthew E. O'Neal

Entomology Publications

Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a serious pest of soybean, Glycine max (L.) Merr., in the North Central United States. Current management recommendations rely on the application of insecticides based on an economic threshold (ET) of 250 aphids per plant. Natural enemies are important in slowing the increase of aphid populations and can prevent them from reaching levels that can cause economic losses. However, biological control of A. glycines is inconsistent and can be affected negatively by the intensity of agricultural activity. We measured the impact of a natural-enemy-free environment on the capacity of the current ET ...