Life Sciences Commons^™

Steinernema Diaprepesi (Nematoda: Steinernematidae): Its Occurrence In Western Mexico And Susceptibility Of Engorded Cattle Ticks Boophilus Microplus (Acari: Ixodidae), Jaime Molina-Ochoa, Khuong B. Nguyen, Martín González-Ramírez, Miguel Guadalupe Quintana-Moreno, Roberto Lezama-Gutiérrez, John E. Foster

Department of Entomology: Faculty Publications

Entomopathogenic nematodes (EPN) belong to the families Steinernematidae and Heterorhabditidae. They infect a wide range of insect hosts and are used to control numerous species of soil borne insect pests (Grewal 2002). We identified EPN genera based on the color of cadavers of the wax moth, Galleria mellonella L., in which Heterorhabditis and Steinernema, produce red and tan colors, respectively, according to Woodring & Kaya (1988). We obtained an isolate of an EPN from sandy loam soil with the Galleria technique (Bedding & Akhurst, 1975) from grasslands in the Campus Tecomán of the Universidad de Colima, and we designated it …

On-Plant Survival And Inheritance Of Resistance To Cry1ab Toxin From Bacillus Thuringiensis In A Field-Derived Strain Of European Corn Borer, Ostrinia Nubilalis, Andre L. B. Crespo, Terence A. Spencer, Analiza P. Alves, Richard L. Hellmich, Erin E. Blankenship, Leonardo C. Magalhães, Blair D. Siegfried

Department of Entomology: Faculty Publications

BACKGROUND: The high dose plus refuge is one of the major components of the resistance management plan mandated for transgenic corn expressing Cry toxins from Bacillus thuringiensis Berliner (Bt) that targets the European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae). This strategy was based on assumptions such as functional recessive inheritance, which has not been previously tested for O. nubilalis. The authors used a field-derived resistant strain of O. nubilalis to define the nature of resistance to Cry1Ab toxin by examining the inheritance and on-plant survival of susceptible and resistant insects and their F1 progeny.

RESULTS: The …

Natural Distribution Of Parasitoids Of Larvae Of The Fall Armyworm, Spodoptera Frugiperda, In Argentina, M Gabriela Murua, Jamie Molina Ochoa, Patricio Fidalgo

Department of Entomology: Faculty Publications

Abstract To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. …

Genes, Gene Flow And Adaptation Of Diabrotica Virgifera Virgifera, Nicholas J. Miller, Thomas Guillemaud, Rosanna Giordano, Blair D. Siegfried, Michael Gray, Lance J. Meinke, Thomas Sappington

Department of Entomology: Faculty Publications

1 Diabrotica virgifera virgifera has emerged as a major pest of cultivated maize, due to a combination of its high capacity to inflict economic damage, adaptability to pest management techniques and invasiveness.

2 This review presents a survey of the current state of knowledge about the genetics Of D. v. virgifera . In addition, the tools and resources currently available to Diabrotica geneticists are identified, as are areas where knowledge is lacking and research should be prioritized.

3 A substantial amount of information has been published concerning the molecular phylogenetic relationships of D. v. virgifera to other chrysomelids.

4 There …

Lyophilization Of Spodoptera Frugiperda (Lepidoptera: Noctuidae) Larvae Yields High-Quality Dna For Use In Aflp Genetic Studies, Pete L. Clark, David J. Isenhour, Steven R. Skoda, Jaime Molina-Ochoa, Claudia Gianni, John E. Foster

Department of Entomology: Faculty Publications

Agricultural research in the 21st century has become a collaborative effort. Research on crop pests like Spodoptera frugiperda (J.E. Smith), commonly known as the fall armyworm (FAW), can involve international collaboration because it is a pest not only in the southern United States, but also in Latin and South America. Our interest to study the genetic variation of 24 subpopulations of FAW from the southern United States, Mexico, Puerto Rico, Brazil and Argentina required insect collection procedures that preserve the integrity of DNA for molecular genetic analysis. The samples were collected primarily from maize (Zea mays L.), but also …

Video-Tracking And On-Plant Tests Show Cry1ab Resistance Influences Behavior And Survival Of Neonate Ostrinia Nubilalis Following Exposure To Bt Maize, Jarrad R. Prasifka, Richard L. Hellmich, Andre L. B. Crespo, Blair Siegfried, David W. Onstad

Department of Entomology: Faculty Publications

To examine how resistance to Bacillus thuringiensis (Bt) toxins influences movement and survival of European corn borer (Ostrinia nubilalis [Hübner]) neonates, the responses of Cry1Ab-resistant , -susceptible, and hybrid (F1) larvae were examined using two different techniques. First, using an automated videotracking system, aspects of O. nubilalis movement were quantified in the presence of artificial diet incorporating 50% non-Bt or insect-resistant Cry1Ab maize tissue. Second, O. nubilalis dispersal and survival were measured 48–72 h after hatching on a Cry1Ab maize plant surrounded by two non-Bt maize plants. Video tracking indicated the presence of Cry1Ab tissue increased the total distance …

Gene Expression Profiling Of Tolerant Barley In Response To Diuraphis Noxia (Hemiptera: Aphididae) Feeding, A. Gutsche, Tiffany Heng-Moss, Gautam Sarath, P. Twigg, Y. Xia, G. Lu, D. Mornhinweg

Department of Entomology: Faculty Publications

Aphids are, arguably, the single most damaging group of agricultural insect pests throughout the world. Plant tolerance, which is a plant response to an insect pest, is viewed as an excellent management strategy. Developing testable hypotheses based on genome-wide and more focused methods will help in understanding the molecular underpinnings of plant tolerance to aphid herbivory. As a first step in this process, we undertook transcript profiling with Affymetrix GeneChip Barley Genome arrays using RNA extracted from tissues of tolerant and susceptible genotypes collected at three hours, three days and six days after Diuraphis noxia introduction. Acquired data were compared …

Oxalic Acid: A Prospective Tool For Reducing Varroa Mite Populations In Package Bees, Nicholas P. Aliano, Marion D. Ellis

Department of Entomology: Faculty Publications

Abstract Numerous studies have investigated using oxalic acid (OA) to control Varroa mites in honey bee colonies. In contrast, techniques for treating package bees with OA have not been investigated. The goal of this study was to develop a protocol for using OA to reduce mite infestation in package bees. We made 97 mini packages of Varroa-infested adult bees. Each package contained 1,613 ± 18 bees and 92 ± 3 mites, and represented an experimental unit. We prepared a 2.8% solution of OA by mixing 35 g OA with 1 l of sugar water (sugar:water = 1:1; w:w). Eight treatments …

Apparent Hybridization Between Trimerotropis Agrestis And Trimerotropis Maritima (Orthoptera: Acrididae) In A Recently Disturbed Habitat, Mathew L. Brust, W. Wyatt Hoback, Robert J. Wright

Department of Entomology: Faculty Publications

In Nebraska, the ranges of Trimerotropis maritima (eastern species) and T. agrestis (western species) overlap but populations usually remain separated by habitat preferences. The morphological and color differences between the species are described. However, around Lake McConaughy, a reservoir on the North Platte River which has declined markedly in depth as a result of recent drought, a habitat was created in which the two species coincide and hybridize frequently. The water level in this reservoir had dropped in excess of 20 meters as of 2007, resulting in large expanses of dunes grading into beach habitats. Grasshoppers were collected in the …

Western Corn Rootworm ( Diabrotica Virgifera Virgifera Leconte) Population Dynamics, Lance Meinke, Thomas W. Sappington, David W. Onstad, Thomas Guillemaud, Nicholas Miller, Judit Komáromi, Nora Levay, Lorenzo Furlan, József Kiss, Ferenc Toth

Department of Entomology: Faculty Publications

1 The western corn rootworm Diabrotica virgifera virgifera LeConte is a major insect pest of field maize, Zea mays L. Larvae can cause substantial injury by feeding on maize roots. Larval feeding may destroy individual roots or root nodes, and reduce plant growth, stability, and yield. Costs associated with managing corn rootworms in continuous maize are annually one of the largest expenditures for insect management in the United States Corn Belt.

2 Even though D. virgifera virgifera has been studied intensively for over 50 years, there is renewed interest in the biology, ecology, and genetics of this species because of …

Adaptation And Invasiveness Of Western Corn Rootworm: Intensifying Research On A Worsening Pest, Michael E. Gray, Thomas W. Sappington, Nicholas Miller, Joachim Moeser, Martin O. Bohn

Department of Entomology: Faculty Publications

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is an established insect pest of maize (Zea mays L.) in North America. The rotation of maize with another crop, principally soybeans, Glycine max (L.), was the primary management strategy utilized by North American producers and remained highly effective until the mid-1990s. In 1995, widespread and severe root injury occurred in east-central Illinois and northern Indiana maize fields that had been annually rotated with soybeans on a regular basis for several decades. The failure of this cultural tactic from a pest management perspective was attributed to a behavioral adaptation by a …

Registration Of ‘Mace’ Hard Red Winter Wheat, Robert A. Graybosch, C. J. Peterson, P. Stephen Baenziger, David D. Baltensperger, Lenis Alton Nelson, Y. Jin, J. Kolmer, B. Seabourn, Roy C. French, Gary L. Hein, T. J. Martin, B. Beecher, T. Schwarzacher, P. Heslop-Harrison

Department of Entomology: Faculty Publications

‘Mace’ (Reg. No. CV-1027, PI 651043) hard red winter wheat (Triticum aestivum L.) was developed by the USDA-ARS and the Nebraska Agricultural Experiment Station and released in December 2007. Mace was selected from the cross Yuma//PI 372129/3/CO850034/4/4*Yuma/5/(KS91H184/Arlin S//KS91HW29/3/NE89526). Mace primarily was released for its resistance to Wheat streak mosaic virus (WSMV) and adaptation to rainfed and irrigated wheat production systems in Nebraska and adjacent areas in the northern Great Plains. Mace was derived from a head selection made from a heterogeneous, in terms of field resistance to WSMV, F5 line. Resistance to WSMV is conditioned by the Wsm-1 gene, …

Gene Expression Profiling Of Tolerant Barley In Response To Diuraphis Noxia (Hemiptera: Aphididae) Feeding, A. Gutsche, Tiffany Heng-Moss, Gautam Sarath, P. Twigg, Yuannan Xia, G. Lu, D. Mornhinweg

Department of Entomology: Faculty Publications

Aphids are, arguably, the single most damaging group of agricultural insect pests throughout the world. Plant tolerance, which is a plant response to an insect pest, is viewed as an excellent management strategy. Developing testable hypotheses based on genome-wide and more focused methods will help in understanding the molecular underpinnings of plant tolerance to aphid herbivory. As a first step in this process, we undertook transcript profiling with Affymetrix GeneChip Barley Genome arrays using RNA extracted from tissues of tolerant and susceptible genotypes collected at three hours, three days and six days after Diuraphis noxia introduction. Acquired data were compared …

Bioavailability Of Chlorantraniliprole And Indoxacarb To Eastern Subterranean Termites (Isoptera: Rhinotermitidae) In Various Soils, Neil A. Spomer, Shripat T. Kamble, Blair D. Siegfried

Department of Entomology: Faculty Publications

A laboratory study was conducted to determine the toxicity of indoxacarb and chlorantraniliprole to Eastern subterranean termites, Reticulitermes flavipes (Kollar) (Isoptera: Rhinotermitidae) resulting from topical applications and exposure to treated soil. Soils with varying organic matter (0.57-3.64%) and chemical characteristics were used in termiticide bioassays. Lethal dose resulting from topical application indicated that chlorantraniliprole was two- to 11-foldmoretoxic than indoxacarb. Lethal concentration assays yielded opposite results where concentrations of indoxacarb in soil that caused either 50 or 90% mortality of R. flavipes workers at 48 and 144 h were two- to six-fold lower than chlorantraniliprole. The bioavailability of indoxacarb and …

Mitochondrial Dna Variation And Range Expansion In Western Bean Cutworm (Lepidoptera: Noctuidae): No Evidence For A Recent Population Bottleneck, Nicholas Miller, David L. Dorhout, Marlin E. Rice, Thomas W. Sappington

Department of Entomology: Faculty Publications

The western bean cutworm, Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is a pest of both corn and dry bean crops. At the beginning of the 21st century, the species began to extend its range out of the Great Plains, eastward through the Corn Belt. This rapid range expansion is remarkable because the species distribution had been stable for at least the previous half century, despite the apparent abundance of suitable habitat (i.e., cornfields) immediately to the east. We hypothesized that if the western bean cutworm had to overcome a stable barrier to movement before starting the current range expansion, it probably …

Expressed Sequence Tags From Larval Gut Of The European Corn Borer (Ostrinia Nubilalis): Exploring Candidate Genes Potentially Involved In Bacillus Thuringiensis Toxicity And Resistance, Chitvan Khajuria, Yu Cheng Zhu, Ming-Shun Chen, Lawrent L. Buschman, Randall A. Higgins, Jianxiu Yao, Andre Lb Crespo, Blair D. Siegfried, Subbaratnam Muthukrishnan, Kun Yan Zhu

Department of Entomology: Faculty Publications

Background: Lepidoptera represents more than 160,000 insect species which include some of the most devastating pests of crops, forests, and stored products. However, the genomic information on lepidopteran insects is very limited. Only a few studies have focused on developing expressed sequence tag (EST) libraries from the guts of lepidopteran larvae. Knowledge of the genes that are expressed in the insect gut are crucial for understanding basic physiology of food digestion, their interactions with Bacillus thuringiensis (Bt) toxins, and for discovering new targets for novel toxins for use in pest management. This study analyzed the ESTs generated from the larval …

European Populations Of Diabrotica Virgifera Virgifera Are Resistant To Aldrin, But Not To Methyl-Parathion, M. Ciosi, S. Toepfer, H. Li, T. Haye, U. Kuhlmann, Haichuan Wang, Blair D. Siegfried, T. Guillemaud

Department of Entomology: Faculty Publications

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is a major pest of cultivated corn in North America and has recently begun to invade Europe. In addition to crop rotation, chemical control is an important option for D. v. virgifera management. However, resistance to chemical insecticides has evolved repeatedly in the USA. In Europe, chemical control strategies have yet to be harmonized and no surveys of insecticide resistance have been carried out. We investigated the resistance to methyl-parathion and aldrin of samples from nine D. v. virgifera field populations originating from two European outbreaks thought to have originated …

Amplified Fragment Length Polymorphism Used For Inter- And Intraspecific Differentiation Of Screwworms (Diptera: Calliphoridae), L. Alamalakala, Steven R. Skoda, John E. Foster

Department of Entomology: Faculty Publications

Morphologically, early immature stages of the economically important pest called screwworms, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), and non-pest secondary screwworms, Cochliomyia macellaria (Fabricius) (Diptera: Calliphoridae), are nearly indistinguishable. Correct identification is crucial to the ongoing eradication and exclusion program protecting the United States, Mexico and Central America from reinvasion of screwworms persistent in South America and the Caribbean. Amplified fragment length polymorphism (AFLP) polymerase chain reaction was used to differentiate populations of C. hominivorax and to discriminate them from C. macellaria. Ten primer pairs screened for interspecific discrimination of C. hominivorax from C. macellaria showed 52 discrete bands, allowing …

Degree-Day Requirements For Eight Economically Important Grasshoppers (Orthoptera: Acrididae) In Nebraska Using Field Data, Mathew L. Brust, William Wyatt Hoback, Robert J. Wright

Department of Entomology: Faculty Publications

The timing of application for the management of rangeland grasshoppers (Orthoptera: Acrididae) is critical, especially as insecticides become more specialized and the use of Insect Growth Regulators becomes more widespread. The general seasonal occurrence of adults of many grasshopper species has been well documented; however, their appearance varies widely between years. We analyzed sweep samples collected over the western two thirds of Nebraska from a 3-yr period and noted the occurrence of adults by region for eight species of rangeland grasshoppers. We analyzed occurrence based on degree-day accumulations for the region and developed estimates of degree-day requirements for these species. …

Efficacy Of Neonicotinoid Seed Treatments To Reduce Soybean Aphid Populations Under Field And Controlled Conditions In Nebraska, Leonardo C. Magalhaes, Thomas E. Hunt, Blair D. Siegfried

Department of Entomology: Faculty Publications

The soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is native to Asia and was recently (2000) detected in North America. Since then, it has become a significant threat to U.S. soybean production. Although neonicotinoid insecticide seed treatments, imidacloprid and thiamethoxam, have been suggested as a method of control, the season-long efficacy is still uncertain. Therefore, the use of imidacloprid and thiamethoxam seed treatments to control soybean aphid in Nebraska were examined. Soybean aphid populations were monitored weekly in an irrigated field study planted during the later half of the typical Nebraska planting window during 2005 and 2006. Imidacloprid and thiamethoxam …