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Iowa State University

Entomology

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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 ...


Insights From Population Genomics To Enhance And Sustain Biological Control Of Insect Pests, Arun Sethuraman, Fredric J. Janzen, David W. Weisrock, John J. Obrycki Jul 2020

Insights From Population Genomics To Enhance And Sustain Biological Control Of Insect Pests, Arun Sethuraman, Fredric J. Janzen, David W. Weisrock, John J. Obrycki

Ecology, Evolution and Organismal Biology Publications

Biological control—the use of organisms (e.g., nematodes, arthropods, bacteria, fungi, viruses) for the suppression of insect pest species—is a well-established, ecologically sound and economically profitable tactic for crop protection. This approach has served as a sustainable solution for many insect pest problems for over a century in North America. However, all pest management tactics have associated risks. Specifically, the ecological non-target effects of biological control have been examined in numerous systems. In contrast, the need to understand the short- and long-term evolutionary consequences of human-mediated manipulation of biological control organisms for importation, augmentation and conservation biological control ...


Juvenile Hormone Regulates The Shift From Migrants To Residents In Adult Oriental Armyworm, Mythimna Separata, Lei Zhang, Lili Cheng, Jason W. Chapman, Thomas W. Sappington, Juanjuan Liu, Yunxia Cheng, Xingfu Jiang Jul 2020

Juvenile Hormone Regulates The Shift From Migrants To Residents In Adult Oriental Armyworm, Mythimna Separata, Lei Zhang, Lili Cheng, Jason W. Chapman, Thomas W. Sappington, Juanjuan Liu, Yunxia Cheng, Xingfu Jiang

Entomology Publications

In migratory insects, increasing evidence has demonstrated juvenile hormone (JH) is involved in regulating adult reproduction and flight. Our previous study demonstrated that the switch from migrants to residents in Mythimna separata could be induced by adverse environmental conditions during a sensitive period in adulthood (the first day post-emergence), but the role of JH in this switch is not clear. Here, we found a significantly different pattern of JH titers between migrants and residents, with migrants showing a slower release of JH during adulthood than residents. Application of JH analogue (JHA) in the 1-day-old adults, significantly accelerated adult reproduction and ...


The Aquatic Neuropterida Of Iowa, David E. Bowles, Gregory W. Courtney Jul 2020

The Aquatic Neuropterida Of Iowa, David E. Bowles, Gregory W. Courtney

Entomology Publications

The fauna of aquatic Neuropterida of Iowa is documented. We list one species of dobsonfly, three species of fishflies, four alderflies (Megaloptera), and two spongillaflies (Neuroptera). New Iowa distributional records are reported for Protosialis americana (Rambur), Sialis joppa Ross, Sialis mohri Ross, Nigronia serricornis (Say), Climacia areolaris (Hagen), and Sisyra vicaria (Walker).


Evaluating Native Bee Communities And Nutrition In Managed Grasslands, D. S. Stein, Diane M. Debinski, John M. Pleasants, Amy L. Toth Jun 2020

Evaluating Native Bee Communities And Nutrition In Managed Grasslands, D. S. Stein, Diane M. Debinski, John M. Pleasants, Amy L. Toth

Ecology, Evolution and Organismal Biology Publications

Native pollinators are important for providing vital services in agroecosystems; however, their numbers are declining globally. Bees are the most efficient and diverse members of the pollinator community; therefore, it is imperative that management strategies be implemented that positively affect bee community composition and health. Here, we test responses of the bee and flowering plant communities to land management treatments in the context of grasslands in the upper Midwestern United States, a critical area with respect to bee declines. Twelve sites were selected to examine floral resources and wild bee communities based on three different types of grasslands: tallgrass prairie ...


Soybean Aphid Biotype 1 Genome: Insights Into The Invasive Biology And Adaptive Evolution Of A Major Agricultural Pest, Rosanna Giordano, Ravi Kiran Donthu, Jonathan H. Badger, Glen L. Hartman, Arian Avalos, Brad S. Coates, Doris Lagos-Kutz, Matthew E. O'Neal, Sijun Liu, Et Al. May 2020

Soybean Aphid Biotype 1 Genome: Insights Into The Invasive Biology And Adaptive Evolution Of A Major Agricultural Pest, Rosanna Giordano, Ravi Kiran Donthu, Jonathan H. Badger, Glen L. Hartman, Arian Avalos, Brad S. Coates, Doris Lagos-Kutz, Matthew E. O'Neal, Sijun Liu, Et Al.

Entomology Publications

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae) is a serious pest of the soybean plant, Glycine max, a major world-wide agricultural crop. We assembled a de novo genome sequence of Ap. glycines Biotype 1, from a culture established shortly after this species invaded North America. 20.4% of the Ap. glycines proteome is duplicated. These in-paralogs are enriched with Gene Ontology (GO) categories mostly related to apoptosis, a possible adaptation to plant chemistry and other environmental stressors. Approximately one-third of these genes show parallel duplication in other aphids. But Ap. gossypii, its closest related species, has the lowest number ...


The Soybean Aphid Suction Trap Network: Sampling The Aerobiological “Soup”, Doris Lagos-Kutz, David J. Voegtlin, David Onstad, David Hogg, David Ragsdale, Kelley Tilmon, Erin Hodgson, Christina Difonzo, Russell Groves, Christian Krupke, Joseph Laforest, Nicholas J. Selter, Emily Duerr, Benjamin Bradford, Glen L. Hartman Apr 2020

The Soybean Aphid Suction Trap Network: Sampling The Aerobiological “Soup”, Doris Lagos-Kutz, David J. Voegtlin, David Onstad, David Hogg, David Ragsdale, Kelley Tilmon, Erin Hodgson, Christina Difonzo, Russell Groves, Christian Krupke, Joseph Laforest, Nicholas J. Selter, Emily Duerr, Benjamin Bradford, Glen L. Hartman

Entomology Publications

The initiation of the soybean aphid suction trap network (STN) in 2001 marked the beginning of a rich and fruitful collaborative effort that has produced a wealth of data about the soybean aphid, other insect species, and other organisms that make up the aerobiological “soup.” Collaboration among researchers, extension specialists, and agriculturalists has provided information about seasonal migration patterns of the soybean aphid and monitoring of other insect species. The physical collections of the “soup” have been stored and used for past research, and will serve as a foundation for future research.


Evaluation Of Xl370a-Derived Maize Germplasm For Resistance To Leaf Feeding By Fall Armyworm, Craig A. Abel, Brad S. Coates, Mark Millard, W. Paul Williams, M. Paul Scott Mar 2020

Evaluation Of Xl370a-Derived Maize Germplasm For Resistance To Leaf Feeding By Fall Armyworm, Craig A. Abel, Brad S. Coates, Mark Millard, W. Paul Williams, M. Paul Scott

NCRPIS Publications and Papers

The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is an economically important insect with larvae damaging maize (Zea mays L.) leaves and ear tissue. The pest has become resistant to several classes of insecticide and Bt-maize grown in some geographical areas. Once discovered and characterized, native sources of maize resistance to this pest could be effectively integrated with existing control tactics. The objective for this study was to test experimental lines derived from maize germplasm XL370A for resistance to leaf feeding by fall armyworm. Plants were grown in the field in 2018 and 2019, artificially infested with fall ...


The Gossypium Longicalyx Genome As A Resource For Cotton Breeding And Evolution, Corrinne E. Grover, Mengqiao Pan, Daojun Yuan, Mark A. Arick Ii, Guanjing Hu, Logan Brase, David M. Stelly, Zefu Lu, Robert J. Schmitz, Daniel G. Peterson, Jonathan F. Wendel, Joshua A. Udall Jan 2020

The Gossypium Longicalyx Genome As A Resource For Cotton Breeding And Evolution, Corrinne E. Grover, Mengqiao Pan, Daojun Yuan, Mark A. Arick Ii, Guanjing Hu, Logan Brase, David M. Stelly, Zefu Lu, Robert J. Schmitz, Daniel G. Peterson, Jonathan F. Wendel, Joshua A. Udall

Ecology, Evolution and Organismal Biology Publications

Cotton is an important crop that has made significant gains in production over the last century. Emerging pests such as the reniform nematode have threatened cotton production. The rare African diploid species Gossypium longicalyx is a wild species that has been used as an important source of reniform nematode immunity. While mapping and breeding efforts have made some strides in transferring this immunity to the cultivated polyploid species, the complexities of interploidal transfer combined with substantial linkage drag have inhibited progress in this area. Moreover, this species shares its most recent common ancestor with the cultivated A-genome diploid cottons, thereby ...


Efficacy Of A Cry1ab Gene For Control Of Maruca Vitrata (Lepidoptera: Crambidae) In Cowpea (Fabales: Fabaceae), Prince C. Addae, Mohammad F. Ishiyaku, Jean-Batiste Tignegre, Malick N. Ba, Joseph B. Bationo, Ibrahim D. K. Atokple, Mumuni Abudulai, Clémentine L. Dabiré-Binso, Fousséni Traore, Mohammed Saba, Muhammed L. Umar, Gloria A. Adazebra, Francis N. Onyekachi, Margaret A. Nemeth, Joseph E. Huesing, Larry R. Beach, Thomas J. V. Higgins, Richard L. Hellmich, Barry R. Pittendrigh Jan 2020

Efficacy Of A Cry1ab Gene For Control Of Maruca Vitrata (Lepidoptera: Crambidae) In Cowpea (Fabales: Fabaceae), Prince C. Addae, Mohammad F. Ishiyaku, Jean-Batiste Tignegre, Malick N. Ba, Joseph B. Bationo, Ibrahim D. K. Atokple, Mumuni Abudulai, Clémentine L. Dabiré-Binso, Fousséni Traore, Mohammed Saba, Muhammed L. Umar, Gloria A. Adazebra, Francis N. Onyekachi, Margaret A. Nemeth, Joseph E. Huesing, Larry R. Beach, Thomas J. V. Higgins, Richard L. Hellmich, Barry R. Pittendrigh

Entomology Publications

Cowpea [Vigna unguiculata (L) Walp.] is an important staple legume in the diet of many households in sub-Saharan Africa. Its production, however, is negatively impacted by many insect pests including bean pod borer, Maruca vitrata F., which can cause 20–80% yield loss. Several genetically engineered cowpea events that contain a cry1Ab gene from Bacillus thuringiensis (Bt) for resistance against M. vitrata were evaluated in Nigeria, Burkina Faso, and Ghana (West Africa), where cowpea is commonly grown. As part of the regulatory safety package, these efficacy data were developed and evaluated by in-country scientists. The Bt-cowpea lines were planted in ...


Genome Scan Detection Of Selective Sweeps Among Biotypes Of The Soybean Aphid, Aphis Glycines, With Differing Virulence To Resistance To A. Glycines (Rag) Traits In Soybean, Glycine Max, Brad S. Coates, Jessica D. Hohenstein, Rosanna Giordano, Ravi Kiran Donthu, Andrew P. Michel, Erin W. Hodgson, Matthew E. O'Neal Jan 2020

Genome Scan Detection Of Selective Sweeps Among Biotypes Of The Soybean Aphid, Aphis Glycines, With Differing Virulence To Resistance To A. Glycines (Rag) Traits In Soybean, Glycine Max, Brad S. Coates, Jessica D. Hohenstein, Rosanna Giordano, Ravi Kiran Donthu, Andrew P. Michel, Erin W. Hodgson, Matthew E. O'Neal

Entomology Publications

Multiple biotypes of soybean aphid, Aphis glycines, occur in North America adapted for survival (virulence) on soybean, Glycine max, with one or more different resistance to A. glycines (Rag) traits. The degree of genome-wide variance between biotypes and the basis of virulence remains unknown, but the latter is hypothesized to involve secreted effector proteins. Between 167,249 and 217,750 single nucleotide polymorphisms (SNPs) were predicted from whole genome re-sequencing of A. glycines avirulent biotype 1 (B1) and virulent B2, B3 and B4 colony-derived iso-female lines when compared to the draft B1 genome assembly, Ag_bt1_v6.0. Differences in nucleotide diversity ...


Pan Traps For Tracking Honey Bee Activity-Density: A Case Study In Soybeans, Ashley L. St. Clair, Adam G. Dolezal, Matthew E. O'Neal, Amy L. Toth Jan 2020

Pan Traps For Tracking Honey Bee Activity-Density: A Case Study In Soybeans, Ashley L. St. Clair, Adam G. Dolezal, Matthew E. O'Neal, Amy L. Toth

Ecology, Evolution and Organismal Biology Publications

To study how honey bees utilize forage resources and guide pollination management plans in crops, a multitude of methods have been developed, but most are time consuming, costly, and require specialized skills. Colored pan traps for monitoring activity-density are a simple, efficient, and cost-effective alternative; however, their usefulness for studying honey bees is not well described. We examined if trap color, location within a field, and the presence of managed colonies affected estimates of honey bee activity-density within soybean fields. Soybeans are visited by pollinators but do not require these visits for seed development. Pan traps, especially those colored blue ...


Estimates Of Common Milkweed (Asclepias Syriaca) Utilization By Monarch Larvae (Danaus Plexippus) And The Significance Of Larval Movement, Kelsey E. Fisher, Richard L. Hellmich, Steven P. Bradbury Jan 2020

Estimates Of Common Milkweed (Asclepias Syriaca) Utilization By Monarch Larvae (Danaus Plexippus) And The Significance Of Larval Movement, Kelsey E. Fisher, Richard L. Hellmich, Steven P. Bradbury

Entomology Publications

The population of monarch butterflies east of the Rocky Mountains has noticeably declined over the past two decades. The decline is due, in part, to loss of breeding and forage habitat in the Southern and Midwestern USA. To support a resilient overwintering population of six hectares of occupied forest canopy, approximately 1.6–1.8 billion additional ramets of milkweed are needed in the summer breeding range. Milkweed establishment that facilitates natural behavior of monarchs is necessary for effective conservation restoration. This study explored the effect of milkweed ramet density on larval search behavior, milkweed utilization, and survival without predation ...


Balancing Disturbance And Conservation In Agroecosystems To Improve Biological Control, John F. Tooker, Matthew E. O'Neal, Cesar Rodriguez-Saona Jan 2020

Balancing Disturbance And Conservation In Agroecosystems To Improve Biological Control, John F. Tooker, Matthew E. O'Neal, Cesar Rodriguez-Saona

Entomology Publications

Disturbances associated with agricultural intensification reduce our ability to achieve sustainable crop production. These disturbances stem from crop-management tactics and can leave crop fields more vulnerable to insect outbreaks, in part because natural-enemy communities often tend to be more susceptible to disturbance than herbivorous pests. Recent research has explored practices that conserve natural-enemy communities and reduce pest outbreaks, revealing that different components of agroecosystems can influence natural-enemy populations. In this review, we consider a range of disturbances that influence pest control provided by natural enemies and how conservation practices can mitigate or counteract disturbance. We use four case studies to ...


Assessing Field‐Scale Risks Of Foliar Insecticide Applications To Monarch Butterfly (Danaus Plexippus) Larvae, Niranjana Krishnan, Yang Zhang, Keith G. Bidne, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury Jan 2020

Assessing Field‐Scale Risks Of Foliar Insecticide Applications To Monarch Butterfly (Danaus Plexippus) Larvae, Niranjana Krishnan, Yang Zhang, Keith G. Bidne, Richard L. Hellmich, Joel R. Coats, Steven P. Bradbury

Entomology Publications

Establishment and maintenance of milkweed plants (Asclepias spp.) in agricultural landscapes of the north central United States are needed to reverse the decline of North America's eastern monarch butterfly (Danaus plexippus) population. Because of a lack of toxicity data, it is unclear how insecticide use may reduce monarch productivity when milkweed habitat is placed near maize and soybean fields. To assess the potential effects of foliar insecticides, acute cuticular and dietary toxicity of 5 representative active ingredients were determined: beta‐cyfluthrin (pyrethroid), chlorantraniliprole (anthranilic diamide), chlorpyrifos (organophosphate), and imidacloprid and thiamethoxam (neonicotinoids). Cuticular median lethal dose values for first ...


Functional Identification Of Fatty Acyl Reductases In Female Pheromone Gland And Tarsi Of The Corn Earworm, Helicoverpa Zea, Xiaoyi Dou, Aijun Zhang, Russell Jurenka Jan 2020

Functional Identification Of Fatty Acyl Reductases In Female Pheromone Gland And Tarsi Of The Corn Earworm, Helicoverpa Zea, Xiaoyi Dou, Aijun Zhang, Russell Jurenka

Entomology Publications

Most moths utilize sex pheromones released by the female to attract a mate. Females produce the sex pheromone in the pheromone gland in a biosynthetic pathway which consists of several key enzymes. Fatty acyl-CoA reductase is one of the key enzymes, which catalyzes the conversion of fatty acyl-CoA to the corresponding alcohol, playing an important role in producing the final proportion of each pheromone component. In Helicoverpa zea, (Z)-11-hexadecenal is the major sex pheromone component in female pheromone glands and previously a large amount of hexadecanal was also found in female and male tarsi. In our previous study, we ...


Estimating Arthropod Survival Probability From Field Counts: A Case Study With Monarch Butterflies, Tyler J. Grant, D. T. Tyler Flockhart, Teresa R. Blader, Richard L. Hellmich, Grace M. Pitman, Sam Tyner, D. Ryan Norris, Steven P. Bradbury Jan 2020

Estimating Arthropod Survival Probability From Field Counts: A Case Study With Monarch Butterflies, Tyler J. Grant, D. T. Tyler Flockhart, Teresa R. Blader, Richard L. Hellmich, Grace M. Pitman, Sam Tyner, D. Ryan Norris, Steven P. Bradbury

Entomology Publications

Survival probability is fundamental for understanding population dynamics. Methods for estimating survival probability from field data typically require marking individuals, but marking methods are not possible for arthropod species that molt their exoskeleton between life stages. We developed a novel Bayesian state‐space model to estimate arthropod larval survival probability from stage‐structured count data. We performed simulation studies to evaluate estimation bias due to detection probability, individual variation in stage duration, and study design (sampling frequency and sample size). Estimation of cumulative survival probability from oviposition to pupation was robust to potential sources of bias. Our simulations also provide ...


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 ...


Milkweed (Asclepias Syriaca) Plant Detection Using Mobile Cameras, Koray Ozcan, Anuj Sharma, Steven P. Bradbury, Dana Schweitzer, Teresa Blader, Sue Blodgett Jan 2020

Milkweed (Asclepias Syriaca) Plant Detection Using Mobile Cameras, Koray Ozcan, Anuj Sharma, Steven P. Bradbury, Dana Schweitzer, Teresa Blader, Sue Blodgett

Natural Resource Ecology and Management Publications

Milkweed (Asclepias spp.) are host plants of monarch butterflies (Danaus plexippus). It is important to detect milkweed plant locations to assess the status and trends of monarch habitat in support of monarch conservation programs. In this paper, we describe autonomous detection of milkweed plants using cameras mounted to vehicles. For detection, we used both aggregated channel features (ACF) for running the detectors on embedded computing platforms with central processing unit and faster region‐based convolutional neural network (Faster R‐CNN) with a ResNet architecture‐based detector that is suitable for graphics processing unit optimized processing. The ACF‐based model produced ...


Employing Very High Frequency (Vhf) Radio Telemetry To Recreate Monarch Butterfly Flight Paths, Kelsey E. Fisher, James S. Adelman, Steven P. Bradbury Jan 2020

Employing Very High Frequency (Vhf) Radio Telemetry To Recreate Monarch Butterfly Flight Paths, Kelsey E. Fisher, James S. Adelman, Steven P. Bradbury

Natural Resource Ecology and Management Publications

The overwintering population of eastern North American monarch butterflies (Danaus plexippus) has declined significantly. Loss of milkweed (Asclepias sp.), the monarch’s obligate host plant in the Midwest United States, is considered to be a major cause of the decline. Restoring breeding habitat is an actionable step towards population recovery. Monarch butterflies are highly vagile; therefore, the spatial arrangement of milkweed in the landscape influences movement patterns, habitat utilization, and reproductive output. Empirical studies of female movement patterns within and between habitat patches in representative agricultural landscapes support recommendations for habitat restoration. To track monarch movement at distances beyond human ...


New Methods Of Removing Debris And High-Throughput Counting Of Cyst Nematode Eggs Extracted From Field Soil, Kalwa Upender, Christopher Legner, Elizabeth Wlezien, Gregory Tylka, Santosh Pandey Oct 2019

New Methods Of Removing Debris And High-Throughput Counting Of Cyst Nematode Eggs Extracted From Field Soil, Kalwa Upender, Christopher Legner, Elizabeth Wlezien, Gregory Tylka, Santosh Pandey

Plant Pathology and Microbiology Publications

The soybean cyst nematode (SCN), Heterodera glycines, is the most damaging pathogen of soybeans in the United States. To assess the severity of nematode infestations in the field, SCN egg population densities are determined. Cysts (dead females) of the nematode must be extracted from soil samples and then ground to extract the eggs within. Sucrose centrifugation commonly is used to separate debris from suspensions of extracted nematode eggs. We present a method using OptiPrep as a density gradient medium with improved separation and recovery of extracted eggs compared to the sucrose centrifugation technique. Also, computerized methods were developed to automate ...


A Potential Role For Phenotypic Plasticity In Invasions And Declines Of Social Insects, Fabio Manfredini, Marina Arbetman, Amy L. Toth Oct 2019

A Potential Role For Phenotypic Plasticity In Invasions And Declines Of Social Insects, Fabio Manfredini, Marina Arbetman, Amy L. Toth

Ecology, Evolution and Organismal Biology Publications

Eusociality, a form of animal social organization involving sterile and reproductive castes, is a rare, but highly ecologically successful form of life. There are striking examples of eusocial species with populations that are ecologically dominant in their native ranges, as well as remarkably successful globally as invasive species; prominent examples include fire ants and yellowjacket wasps. At the same time, there have been startling population declines in other social insects, notably bumble bees. Here, we explore the possible role of phenotypic plasticity in invasion biology and declines of social insect species. This topic is of particular interest, because social insects ...


Inhibitors Of Eicosanoid Biosynthesis Reveal That Multiple Lipid Signaling Pathways Influence Malaria Parasite Survival In Anopheles Gambiae, Hyeogsun Kwon, Ryan C. Smith Sep 2019

Inhibitors Of Eicosanoid Biosynthesis Reveal That Multiple Lipid Signaling Pathways Influence Malaria Parasite Survival In Anopheles Gambiae, Hyeogsun Kwon, Ryan C. Smith

Entomology Publications

Eicosanoids are bioactive signaling lipids derived from the oxidation of fatty acids that act as important regulators of immune homeostasis and inflammation. As a result, effective anti-inflammatory drugs have been widely used to reduce pain and inflammation which target key eicosanoid biosynthesis enzymes. Conserved from vertebrates to insects, the use of these eicosanoid pathway inhibitors offer opportunities to evaluate the roles of eicosanoids in less-characterized insect systems. In this study, we examine the potential roles of eicosanoids on malaria parasite survival in the mosquito Anopheles gambiae. Using Plasmodium oocyst numbers to evaluate parasite infection, general or specific inhibitors of eicosanoid ...


Gene Pyramids And The Balancing Act Of Keeping Pests At Bay, Gustavo C. Macintosh Sep 2019

Gene Pyramids And The Balancing Act Of Keeping Pests At Bay, Gustavo C. Macintosh

Biochemistry, Biophysics and Molecular Biology Publications

Pyramiding R genes is a common strategy used by breeders to enhance resistance and increase durability of resistance in crops. However, the molecular mechanisms that mediate R gene interactions are not known. Kamphuis et al. (2019) analyzed Medicago truncatula plants carrying two genes that confer resistance to bluegreen aphids. They identified a potential phytohormone crosstalk triggered by the combined R gene action in response to aphid feeding that enhances resistance and minimizes R gene-associated fitness costs to the plant.


Influence Of Host Plant, Geography And Pheromone Strain On Genomic Differentiation In Sympatric Populations Of Ostrinia Nubilalis, Brad S. Coates, Genevieve M. Kozak, Kyung Seok Kim, Jing Sun, Yangzhou Zhang, Shelby J. Fleischer, Erik B. Dopman, Thomas W. Sappington Sep 2019

Influence Of Host Plant, Geography And Pheromone Strain On Genomic Differentiation In Sympatric Populations Of Ostrinia Nubilalis, Brad S. Coates, Genevieve M. Kozak, Kyung Seok Kim, Jing Sun, Yangzhou Zhang, Shelby J. Fleischer, Erik B. Dopman, Thomas W. Sappington

Entomology Publications

Patterns of mating for the European corn borer (Ostrinia nubilalis) moth depend in part on variation in sex‐pheromone blend. The ratio of (E)‐11‐ and (Z)‐11‐tetradecenyl acetate (E11‐ and Z11‐14:OAc) in the pheromone blend that females produce and males respond to differs between strains of O. nubilalis. Populations also vary in female oviposition preference for and larval performance on maize (C4) and non‐maize (C3) host plants. The relative contributions of sexual and ecological trait variation to the genetic structure of O. nubilalis remains unknown. Host‐plant use (13C/14C ratios) and genetic differentiation were ...


Iowa Soybean Research Center 2019 Stakeholder Report, Kara Berg, Jill Cornelis, Steve May, Gregory L. Tylka Sep 2019

Iowa Soybean Research Center 2019 Stakeholder Report, Kara Berg, Jill Cornelis, Steve May, Gregory L. Tylka

Iowa Soybean Research Center Reports

The Iowa Soybean Research Center works in partnership with the Iowa Soybean Association, industry leaders, farmers and researchers at Iowa State University. The goal of this collaborative effort is to identify and fund research in the areas of soybean production and protection. The information in this report gives an overview of the Iowa Soybean Research Center, its partnerships, and the research projects that have been funded.


Transcriptional Comparison Between Pheromone Gland-Ovipositor And Tarsi In The Corn Earworm Moth Helicoverpa Zea, Xiaoyi Dou, Sijun Liu, Seung-Joon Ahn, Man-Yeon Choi, Russell Jurenka Sep 2019

Transcriptional Comparison Between Pheromone Gland-Ovipositor And Tarsi In The Corn Earworm Moth Helicoverpa Zea, Xiaoyi Dou, Sijun Liu, Seung-Joon Ahn, Man-Yeon Choi, Russell Jurenka

Entomology Publications

The corn earworm, Helicoverpa zea, utilizes (Z)-11-hexadecenal as the major sex pheromone component. The saturated fatty acid derivative hexadecanal is also found in the pheromone gland and recently a large amount (0.5–1.5 μg) was found in male tarsi with lower amounts (0.05–0.5 μg) in female tarsi. In this study, we compared the transcriptome between female pheromone glands (including the ovipositor) and female and male tarsi to identify differences between these tissues, particularly the genes involved in sex pheromone biosynthesis and chemosensation. We found transcripts encoding 9 fatty acyl-CoA desaturases, 20 fatty acyl-CoA reductases ...


Satellite Imaging And Long-Term Mosquito Surveillance Implicate The Influence Of Rapid Urbanization On Culex Vector Populations, Eleanor N. Field, Ryan E. Tokarz, Ryan C. Smith Aug 2019

Satellite Imaging And Long-Term Mosquito Surveillance Implicate The Influence Of Rapid Urbanization On Culex Vector Populations, Eleanor N. Field, Ryan E. Tokarz, Ryan C. Smith

Entomology Publications

The ecology and environmental conditions of a habitat have profound influences on mosquito population abundance. As a result, mosquito species vary in their associations with particular habitat types, yet long-term studies showing how mosquito populations shift in a changing ecological landscape are lacking. To better understand how land use changes influence mosquito populations, we examined mosquito surveillance data over a thirty-four-year period for two contrasting sites in central Iowa. One site displayed increasing levels of urbanization over time and a dramatic decline in Culex pipiens group (an informal grouping of Culex restuans, Culex pipiens, and Culex salinarius, referred to as ...


Pheromone Gland Transcriptome Of The Pink Bollworm Moth, Pectinophora Gossypiella: Comparison Between A Laboratory And Field Population, Xiaoyi Dou, Sijun Liu, Victoria Soroker, Ally Harari, Russell Jurenka Jul 2019

Pheromone Gland Transcriptome Of The Pink Bollworm Moth, Pectinophora Gossypiella: Comparison Between A Laboratory And Field Population, Xiaoyi Dou, Sijun Liu, Victoria Soroker, Ally Harari, Russell Jurenka

Entomology Publications

The pink bollworm, Pectinophora gossypiella, is a world-wide pest of cotton and in some parts of the cotton growing region is controlled by the mating disruption technique using synthetic sex pheromone. The sex pheromone consists of two compounds, (Z,Z)- and (Z,E)-7,11-hexadecadienyl acetates, in about a 50:50 ratio. However, recently, a population with sex pheromone compound ratios of about 62:38 were found in cotton fields that use mating disruption in Israel. To investigate how the change developed, we compared the pheromone gland transcriptomes between a reference laboratory population and a population obtained from an Israeli ...