Agronomy and Crop Sciences Commons^™

First Record Of The Invasive Chenopodium Aphid, Hayhurstia Atriplicis (Linnaeus, 1761) (Hemiptera: Aphididae), In Colombia, Takumasa Kondo, Roberto Rosero, Jackeline Gaviria

Insecta Mundi

The chenopodium aphid, Hayhurstia atriplicis (Linnaeus, 1761) (Hemiptera: Aphididae), is reported for the first time in Colombia. The aphid was found on the aerial parts of the quinoa plant, Chenopodium quinoa Willd. (Amaranthaceae), especially on the leaves, in five municipalities in the department of Cauca, Colombia. Brief information on its natural enemies, distribution and biology is provided. This is the only aphid in Colombia known to cause malformations on the leaves of quinoa plants. In South America, this aphid has been found previously only in Ecuador, where it was reported for the first time in 2023 based on specimens collected …

Impact Of Plant Defenses And Aphid-Associated Microbes In Modulating Sorghum-Sugarcane Aphid Interactions, Edith Ikuze

Department of Entomology: Dissertations, Theses, and Student Research

Sorghum (Sorghum bicolor) is a vital cereal crop globally, facing challenges from invasive pests such as the sugarcane aphid (SCA; Melanaphis sacchari). To elucidate mechanisms of sorghum resistance to SCA, we examined the role of plant defenses and the influence of aphid-associated microbes in modulating sorghum defenses. Lignin is a complex heterogenous polymer present in nearly all plant cell walls that plays a critical role in protecting plants from various stresses. In this study, we investigated the role of the caffeoyl coenzyme-A O-methyltransferase (CCoAOMT), one of the core enzymes in monolignol biosynthesis pathway that leads to lignin …

Predicting The Potential Distribution Of Pseudococcus Longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) In South Korea Using A Climex Model, Su Bin Kim, Soo-Jung Suh

Insecta Mundi

Pseudococcus longispinus (Targioni-Tozzetti) (Hemiptera: Pseudococcidae) is a widely-distributed pest that feeds on many economically important hosts, particularly tropical fruits and ornamentals. The potential distribution of this mealybug pest in South Korea remains a primary concern because of its high incidence of interceptions screened during inspection. Hence, this species prompted a modelling effort to assess its potential risk of introduction. Potential risk maps were developed for this pest with a CLIMEX model based on occurrence records under environmental data. The potential distribution of these pests in South Korea in the 2020s, 2050s and 2090s was projected based on the RCP 8.5 …

Hilling As A Management Tactic And Tool For Understanding Soybean Gall Midge (Resseliella Maxima Gagné), Pragya Gupta

Department of Entomology: Dissertations, Theses, and Student Research

Soybean gall midge (Resseliella maxima Gagné, SGM) emerged as a new species in the United States Midwest in 2019, causing injury to soybean (Glycine max L.) Infestation of R. maxima starts with females laying eggs in the fissures or cracks that develop at the base of soybean during the V2-V3 growth stage. The emerged larvae feed on the stem internally, leading to wilting and death of the plants. With knowledge gaps in biology and behavior, management strategies for this pest are challenging. Hilling is a cultural practice causing soil to cover the base of stems and is …

Pollinator Communities And Their Ecosystem Services At Conservation Grasslands And Adjacent Croplands, Araceli Gomez Villegas

Department of Entomology: Dissertations, Theses, and Student Research

Pollinators are intrinsically linked to the success of unmanaged and managed ecosystems by providing pollination services that aid in the reproduction of wildflowers and many crops. Land use change, habitat loss, fragmentation, and related landscape-level phenomena (for example, increased pesticide exposure) threaten pollinators and have been associated with population declines. In the Midwestern region of the United States, land conversion of native prairies and grasslands to row-crop agriculture has been one of the largest contributors to pollinator habitat loss. Conservation programs, such as the Conservation Reserve Program, have worked towards removing environmentally sensitive lands from agriculture production and enrolling them …

Comparison Of Insecticide And Trap Crop Management Practices For The Control Of Acalymma Vittatum (Coleoptera: Chrysomelidae) In Cucumbers, Keely Wright

Department of Entomology: Distance Master of Science Projects

The striped cucumber beetle (Acalymma vittatum (F.)) is a specialist herbivore pest, feeding on plants in the Cucurbitaceae family across North America. Adult beetles migrate into cucurbit fields from the field edges to feed on the emerged plant parts. Control methods can include insecticides, cultural practices, and some biological control species, or a combination of multiple methods, each having their own advantages and disadvantages. A push-pull trap crop management system using blue hubbard squash (Cucurbita maxima Duchesne) and nasturtiums was established and compared to a lambda-cyhalothrin (Matador 120EC) foliar insecticide control approach in a cucumber crop. Lambda-cyhalothrin, applied …

A Review Of The Wheat Stem Sawfly, Cephus Cinctus Norton (Hymenoptera: Cephidae), Bethany Thomas

Department of Entomology: Distance Master of Science Projects

The wheat stem sawfly, Cephus cinctus Norton (Hymenoptera: Cephidae) is a native stem-mining insect pest of significant economic importance within the Northern Great Plains of the United States and the prairie provinces of Canada (Criddle, 1923). Cephus cinctus adult females specifically attack large-stemmed grasses, originally feral and later adapted to cultivated grasses, with dryland wheat, Triticum aestivum L. (Poaceae), as the most notable host (Morrill & Kushnak, 1996). As all but two weeks of the sawfly’s lifecycle is contained within a host-grass, understanding the ecological history, biological interactions, and economic impacts between C. cinctus and T. aestivum is …

Site-Specific Pest Management In Nebraska Corn And Soybean Production Systems, Zachary D. Rystrom

Doctor of Plant Health Program: Dissertations and Student Research

Site-specific management (SSM) is widely used by farm producers to fertilize their fields. However, whole field management is currently practiced in integrated pest management (IPM). Site-specific management and agricultural technology can improve IPM especially when precision application of inputs can reduce selection pressure on pest populations, benefit the environment, or save costs of inputs. There is potential for site-specific pest management (SSPM) where pests, or environments vary spatially, and recommended management practices can be applied with precision. Three case studies are evaluated for SSPM to be applied in Nebraska corn and soybean production systems including corn rootworm, preemergence herbicides, and …

Soybean Gall Midge (Resseliella Maxima Gagné): Insecticide Efficacy And Seasonal Larval Abundance, Vilma Maria Montenegro Castro

Department of Entomology: Dissertations, Theses, and Student Research

Soybean gall midge, Resseliella maxima Gagné was recently identified as a new species injuring soybean in Nebraska, Iowa, South Dakota, Minnesota, and Missouri. Resseliella maxima injury is caused by its three instars that feed on tissues within the soybean stem. Infested plants exhibit a darkening of the stem, disrupting nutrient flow within the plant and can lead to wilting or death of plants. Total yield losses can occur in the first 30 m of the field in heavily infested sites. The biology and behavior of this newly described insects is not well understood and management strategies for the management of …

The Impact Of Beneficial Organisms In Corn Agroecosystems, Callie Rosalind Braley

Doctor of Plant Health Program: Dissertations and Student Research

Corn is one of the world’s, and Nebraska’s, most important crops. Millions of acres are planted to corn each year in the Cornhusker State. However, each year there are a plethora of arthropod, weed, and microorganism pests that rob farmers of reaching their maximum yield potential. There are many options available to manage these pests in corn agroecosystems, but one option is often underutilized: beneficial organisms. For each pest, there are a variety of natural enemies that can assist in mitigating the damage caused by pests.

Many beneficial organisms exist, and they can be grouped by the type of pest …

American Burying Beetle, Plant Richness, And Soil Property Responses To Collapse Of Juniperus Virginiana Woodlands With Fire, Alison Ludwig

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Grasslands are declining in the Great Plains due to land use changes, woody plant encroachment, and loss of historic fire cycles. Prescribed burn associations have utilized prescribed fire to collapse invading woodlands and allow the restoration of grasslands. This fire is considered “extreme” because it is capable of changing the structure and function of an ecosystem. Our study site is the Loess Canyons Experimental Landscape, a long-term, ecoregion-scale experiment to apply prescribed fire across the region to restore grasslands. The Nebraska Natural Legacy Project established the Loess Canyons ecoregion as a Biologically-Unique Landscape in 2005 with the state’s wildlife action …

High Plains Wheat Mosaic Virus: An Enigmatic Disease Of Wheat And Corn Causing The High Plains Disease, Satyanarayana Tatineni, Gary Hein

Department of Entomology: Faculty Publications

Brief history: In 1993, severe mosaic and necrosis symptoms were observed on corn (maize) and wheat from several Great Plains states of the USA. Based on the geographical location of infections, the disease was named High Plains disease and the causal agent was tentatively named High Plains virus. Subsequently, researchers renamed this virus as maize red stripe virus and wheat mosaic virus to represent the host and symptom phenotype of the virus. After sequencing the genome of the pathogen, the causal agent of High Plains disease was officially named as High Plains wheat mosaic virus. Hence, High Plains virus, …

Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

This study is focused on the population of federally-endangered American burying beetles in south-central Nebraska. It is focused on changes in land cover over time and at several levels of spatial scale, and how management efforts are impacting both the beetle and a changing landscape. Our findings are applicable to a large portion of the Great Plains, which is undergoing the same shift from grassland to woodland, and to areas where the beetle is still found.

Integrated Crop–Livestock Systems In Paddy Fields: New Strategies For Flooded Rice Nutrition, Luiz Gustavo De O. Denardin, Amanda P. Martins, Felipe De C. Carmona, Murilo G. Veloso, Gabriela I. Carmona, Paulo César De F. Carvalho, Ibanor Anghinoni

Department of Entomology: Faculty Publications

Integrated crop–livestock systems (ICLSs) appear as a good alternative to increase nutrient use efficiency (NUE) in rice (Oryza sativa L.) through the improvement in nutrient cycling and soil chemical attributes in paddy fields. The objective of this study was to evaluate the impact of an ICLS on soil chemical attributes and on the fertilization requirement of N, P, and K by flooded rice in the Brazilian subtropical region. Nutritional status, yield, and NUE of flooded rice were evaluated by fertilization trials through rice response to different fertilization rates of N, P, and K. Soil chemical attributes were evaluated at …

Establishment Of Wildflower Islands To Enhance Roadside Health And Aesthetics, Walter Schacht, Judy Wu-Smart

Nebraska Department of Transportation: Research Reports

Wildflowers are crucial in the ecological function of the low-input roadside plant communities in terms of water andnutrient cycling, nutrient inputs such as nitrogen, total plant canopy cover, stand longevity, and provision of habitat for numerous small animals. Further, wildflowers provide critical foraging and nesting resources for birds, insects, and other wildlife. Unfortunately, habitat loss from agricultural and urban development has led to rapid population declines in wild bees and other pollinators across the US, thereby jeopardizing not only food production but also the sustainability of our natural landscapes (Kearns & Inouye, 1997). One way to mitigate wild bee decline …

Dual Biological Control: Characterization Of Fungi And Bacteria To Control Granary Weevil And Fungal Pathogens Of Stored Grain, Gülçin Ercan

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Cereals are main food sources for humans and animals. However, during storage, cereal grains can be infested by insects and fungi. One of the most important insect storage pests is Sitophilus granarius (L., Coleoptera: Curculionidae). Adults and larvae can cause serious grain losses. In addition to insect pests, fungal pathogens may also invade the grain and cause economic loss, including contamination with mycotoxins, which threaten mammal health by causing serious disease. The most common mycotoxigenic grain fungi are species that belong to the genera Fusarium, Aspergillus and Penicillium. Currently, the most commonly used management strategies for insect and …

Global Responses Of Resistant And Susceptible Sorghum (Sorghum Bicolor) To Sugarcane Aphid (Melanaphis Sacchari), Hannah M. Tetreault, Sajjan Grover, Erin Scully, Tammy Gries, Nathan A. Palmer, Gautam Sarath, Joe Louis, Scott E. Sattler

Department of Entomology: Faculty Publications

The sugarcane aphid (Melanaphis sacchari) has emerged as a significant pest for sorghum. The use of sugarcane aphid-resistant sorghum germplasm with integrated pest management strategies appears to be an excellent solution to this problem. In this study, a resistant line (RTx2783) and a susceptible line (A/BCK60) were used to characterize the differences in plant responses to the sugarcane aphid through a series of experiments, which examined global sorghum gene expression, aphid feeding behavior and inheritance of aphid resistance. The global transcriptomic responses to sugarcane aphids in resistant and susceptible plants were identified using RNA-seq and compared to the …

Soil Fauna Accelerate Dung Pat Decomposition And Nutrient Cycling Into Grassland Soil, Kenneth S. Evans, Martha Mamo, Ana Wingeyer, Walter Schacht, Kent Eskridge, Jeff Bradshaw, Daniel Ginting

Department of Agronomy and Horticulture: Faculty Publications

Soil fauna play critical roles in various ecosystem functions and services, but empirical data measuring their impact on dung pat decomposition and subsequent nutrient cycling into rangeland soils are limited. The objective of this study was to quantify the effect of soil fauna, using dung beetle as an indicator, on dung decomposition and subsequent translocation of dung nutrients into grassland soil over time. A field experiment was conducted early in the summer season and late in the summer season of 2014 and 2015. In each season, dung beetle abundance, changes in dung properties, and subsequent translocation of dung nutrients into …

Double-Stranded Rna Binding Protein, Staufen, Is Required For The Initiation Of Rnai In Coleopteran Insects, June-Sun Yoon, Kanakachari Mogilicherla, Dhandapani Gurusamy, Xien Chen, Shankar C. R. R. Chereddy, Subba R. Palli

Entomology Faculty Publications

RNA interference (RNAi) is being used to develop methods to control pests and disease vectors. RNAi is robust and systemic in coleopteran insects but is quite variable in other insects. The determinants of efficient RNAi in coleopterans, as well as its potential mechanisms of resistance, are not known. RNAi screen identified a double-stranded RNA binding protein (StaufenC) as a major player in RNAi. StaufenC homologs have been identified in only coleopteran insects. Experiments in two coleopteran insects, Leptinotarsa decemlineata and Tribolium castaneum, showed the requirement of StaufenC for RNAi, especially for processing of double-stranded RNA (dsRNA) to small interfering …

Cloning And Characterization Of A Pyrethroid Pesticide Decomposing Esterase Gene, Est3385, From Rhodopseudomonas Palustris Psb-S, Xiangwen Luo, Deyong Zhang, Xuguo Zhou, Jiao Du, Songbai Zhang, Yong Liu

Entomology Faculty Publications

Full length open reading frame of pyrethroid detoxification gene, Est3385, contains 963 nucleotides. This gene was identified and cloned based on the genome sequence of Rhodopseudomonas palustris PSB-S available at the GneBank. The predicted amino acid sequence of Est3385 shared moderate identities (30–46%) with the known homologous esterases. Phylogenetic analysis revealed that Est3385 was a member in the esterase family I. Recombinant Est3385 was heterologous expressed in E. coli, purified and characterized for its substrate specificity, kinetics and stability under various conditions. The optimal temperature and pH for Est3385 were 35 °C and 6.0, respectively. This enzyme could …

Sequence Analysis Of The Potato Aphid Macrosiphum Euphorbiae Transcriptome Identified Two New Viruses, Marcella A. Texeira, Noa Sela, Hagop S. Atamian, Ergude Bao, Rita Chaudhury, Jacob Macwilliams, Jiangman He, Sophie Mantelin, Thomas Girke, Isgouhi Kaloshian

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The potato aphid, Macrosiphum euphorbiae, is an important agricultural pest that causes economic losses to potato and tomato production. To establish the transcriptome for this aphid, RNA-Seq libraries constructed from aphids maintained on tomato plants were used in Illumina sequencing generating 52.6 million 75±105 bp paired-end reads. The reads were assembled using Velvet/Oases software with SEED preprocessing resulting in 22,137 contigs with an N50 value of 2,003bp. After removal of contigs from tomato host origin, 20,254 contigs were annotated using BLASTx searches against the non-redundant protein database from the National Center for Biotechnology Information (NCBI) as well as IntereProScan. …

Resistance In 27 Rice Cultivars To Sugarcane Borer (Lepidoptera: Crambidae), F. Correa, C. L. T. Silva, A. P. Pelosi, A. C. S. Almeida, E. A. Heinrichs, J. A. F. Barrigossi, F. G. Jesus

Department of Entomology: Faculty Publications

Rice (Oryza sativa L.) is considered one of the most important crops in the world, and the sugarcane borer, Diatraea saccharalis Fabricius (Lepidoptera: Crambidae), is among the key pests damaging the crop in the Americas. The objective of this work was to identify rice genotypes as a source of resistance to D. saccharalis. Rice plants were infested in the greenhouse and subsequently evaluated for damage, larval weight and survival, and stem size. The cultivars “Bonança,” “Caripuna,” “IR 42,” “Canela de Ferro,” “SWA Norte,” “BR IRGA 409,” “Pepita,” “Serra Dourada,” “Araguaia,” “Xingú,” “Tangará,” and “Soberana” showed antibiosis, antixenosis, or …

Detection And Epidemic Dynamic Of Tocv And Ccyv With Bemisia Tabaci And Weed In Hainan Of China, Xin Tang, Xiaobin Shi, Deyong Zhang, Fan Li, Fei Yan, Youjun Zhang, Yong Liu, Xuguo Zhou

Entomology Faculty Publications

Background: In recent years, two of the crinivirus, Tomato chlorosis virus (ToCV) and Cucurbit chlorotic yellows virus (CCYV) have gained increasing attention due to their rapid spread and devastating impacts on vegetable production worldwide. Both of these viruses are transmitted by the sweet potato whitefly, Bemisia tabaci (Gennadius), in a semi-persistent manner. Up to now, there is still lack of report in Hainan, the south of China.

Methods: We used observational and experimental methods to explore the prevalence and incidence dynamic of CCYV and ToCV transmitted by whiteflies in Hainan of China.

Results: In 2016, the chlorosis symptom was observed …

Over-Summering Ecology Of The Wheat Curl Mite (Aceria Tosichella Keifer), Anthony J. Mcmechan

Department of Entomology: Dissertations, Theses, and Student Research

The wheat-mite-virus complex is a consistent and significant threat to winter wheat production in the western Great Plains. This complex consists of three viruses (Wheat streak mosaic virus, Triticum mosaic virus, and Wheat mosaic virus that are transmitted by the wheat curl mite (Aceria tosichella Keifer). Yield impacts from this complex are typically associated with the presence of volunteer wheat that emerges prior to harvest as a result of hail occurring during the heading stages of wheat in early summer. Historical literature on pre-harvest germination has been primarily focused on accelerating breeding programs; however, critical gaps in knowledge exist on …

Effect Of Dung Beetles On Dung Decomposition And Nuntrient Cycling In A Nebraska Rangeland, Kenneth Shay Evans

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Management practice can have impacts on the abundance and frequency of dung beetle populations and nutrient cycling in grazing systems. Also, agriculture and livestock production land use is a considerable source of anthropogenic greenhouse gas (GHG) emissions, which are known to be one of the causes of global climate change. In this study, we evaluated the effect of dung beetle presence on the fluxes of greenhouse gasses (GHG’s) from dung pats in the semi-arid Sandhills region of Nebraska, by using closed chambers to measure the fluxes of carbon dioxide (CO₂), methane (CH₄) and nitrous oxide (N …

Effects Of Host-Plant Density On Herbivores And Their Parasitoids: A Field Experiment With A Native Perennial Legume, Andrea Salas

FIU Electronic Theses and Dissertations

Senna mexicana chapmanii (Fabaceae: Caesalpinoideae), an attractive and threatened species native to pine rocklands of southern Florida, is consumed by folivorous caterpillars of Sulfur butterflies (Lepidoptera: Pieridae). Caterpillars may be deterred or eaten by predators, but also very important are parasitoids, both flies and wasps. This study investigated the effects of plant density on Sulfur caterpillar numbers and rates of parasitization.

Senna mexicana chapmanii plantations were established at agricultural and urban areas; both sites are adjacent to protected pine rockland areas. Sulfur butterfly immature stages were collected and reared to glean information regarding number of herbivores and rates of parasitization. …

A Brief History Of Corn: Looking Back To Move Forward, Jon Derek Pruitt

Doctor of Plant Health Program: Dissertations and Student Research

Maize was domesticated from teosinte in Mexico some 7,000 to 10,000 years ago and quickly spread through the Americas. It has become one of the most important crops at a local and global level. Two types, Northern Flint corn and Southern Dent corns provided the basis of the genetic background of modern maize hybrids. The development of hybrids, first double-cross and later single-cross hybrids, along with a transition to high input farming provided huge yield increases, which have continued to improve with improving technology.

Increase in maize production also caused a rise in Western corn Rootworm (Diabrotica virgifera virgifera …

Aphid Performance Changes With Plant Defense Mediated By Cucumber Mosaic Virus Titer, Xiaobin Shi, Yang Gao, Shuo Yan, Xin Tang, Xuguo Zhou, Deyong Zhang, Yong Liu

Entomology Faculty Publications

Background: Cucumber mosaic virus (CMV) causes appreciable losses in vegetables, ornamentals and agricultural crops. The green peach aphid, Myzus persicae Sulzer (Aphididae) is one of the most efficient vectors for CMV. The transmission ecology of aphid-vectored CMV has been well investigated. However, the detailed description of the dynamic change in the plant-CMV-aphid interaction associated with plant defense and virus epidemics is not well known.

Results: In this report, we investigated the relationship of virus titer with plant defense of salicylic acid (SA) and jasmonic acid (JA) during the different infection time and their interaction with aphids in CMV-infected tobacco plants. …

Managing Drought Stress In California Agricultural Systems, Gregory D. Brittain Jr.

Doctor of Plant Health Program: Dissertations and Student Research

California is currently facing a historic drought, and this has led many farmers in the state to severely cut back on irrigation. Optimal use of water for irrigation requires a comprehensive understanding of how plants respond physiologically to water stress (Chapter 1). By monitoring water requirements in crops and managing irrigation to meet those requirements, growers can significantly reduce water use (Chapter 2). This can be done through improving application efficiency of irrigation technology as well as increasing the water use efficiency of the crops themselves. Deficit irrigation practices can be used to manipulate the physiology of water use in …

Canola: A Modern Crop For A Modern Era, Kenneth J. Roché

Doctor of Plant Health Program: Dissertations and Student Research

The University of Nebraska-Lincoln Doctor of Plant Health program is a professional doctorate program with a comprehensive approach to plants and agriculture. The program emphasizes a broad interdisciplinary education across all plant-related disciplines, practical learning, research, and experience through internships. For my final required internship, I worked as a senior agricultural research intern with Research Designed for Agriculture (RD4AG) in Montana. RD4AG is a contract research organization based in Yuma, AZ with over thirty-years of experience. During my three month internship at RD4AG in Montana, a large portion of my responsibilities centered on managing regulated canola trials that were undertaken …