Life Sciences Commons^™

Genetic Variability Of Spined Soldier Bugs (Hemiptera: Pentatomidae) Sampled From Distinct Field Sites And Laboratory Colonies In The United States, Fatima Mustafa, Muhammad Ullah, Kathleen M. Kneeland, Thomas A. Coudron, W. Wyatt Hoback, S. R. Skoda, Jaime Molina-Ochoa, John E. Foster

Department of Entomology: Faculty Publications

The spined soldier bug, Podisus maculiventris (Say), is an important biological control agent of agricultural and forest pests; and it preys on eggs and larvae of lepidopteran and coleopteran species. Genetic variability among field samples collected from Michigan, Mississippi, Missouri, Florida and established laboratory colonies was examined using Amplified Fragment Length Polymorphism-Polymerase Chain Reaction (AFLP-PCR). Four AFLP primer pairs generated a total of 340 molecular markers for evaluation. Results from Analysis of Molecular Variance showed that the majority of the genetic variation occurred within populations (individuals from each sample site). Nei’s method indicated reduced genetic diversity in laboratory populations compared …

Effect Of The Insecticide Lambda-Cyhalothrin On Rice Spider Populations In Southern Brazil, Everton N. L. Rodrigues, Milton De S. Mendonça Jr., Leila L. Fritz, Elvis A. Heinrichs, Lídia Fiuza

Department of Entomology: Faculty Publications

The adverse effect that insecticides have on spider populations is of major concern since these predators are a component in the biological control of rice insect pest populations. This study was designed to determine the effect of the pyrethroid insecticide Lambda-cyhalothrin on spider populations in rice fields. Treatments consisted of plots treated once with the insecticide and untreated plots (control). Spiders were sampled four times per crop year over a two-year period in each of three sites in the state of Rio Grande dol Sul, Brazil. Treatments were replicated four times. Sweep net sampling was conducted to sample the araneofauna. …

Dna Barcoding Distinguishes Pest Species Of The Black Fly Genus Cnephia (Diptera: Simuliidae), I. M. Confitti, K. P. Pruess, A. Cywinska, T. O. Powers, D. C. Currie

Department of Entomology: Faculty Publications

Accurate species identification is essential for cost-effective pest control strategies. We tested the utility of COI barcodes for identifying members of the black fly genus Cnephia Enderlein (Diptera: Simuliidae). Our efforts focus on four Nearctic Cnephia species—Cnephia dacotensis (Dyar & Shannon), Cnephia eremities Shewell, Cnephia ornithophilia (Davies, Peterson & Wood), and Cnephia pecuarum (Riley)—the latter two being current or potential targets of biological control programs. We also analyzed one Palearctic species, Cnephia pallipes (Fries). Although Cnephia adults can be identified anatomically to species, control programs target the larval stage, which is difficult or impossible to distinguish morphologically. By using …

Biotic Potential And Reproductive Parameters Of Spodoptera Eridania (Stoll) (Lepidoptera, Noctuidae) In The Laboratory, Débora G. Montezano, Alexandre Specht, Daniel Ricardo Sosa-Gómez, Vânia F. Roque-Specht, Neiva M. Barros

Department of Entomology: Faculty Publications

Biotic potential and reprodutcive parameters of Spodoptera eridania (Stoll) (Lepidoptera, Noctuidae) in the laboratory: This study aimed to evaluate the biotic potential and reproductive parameters of Spodoptera eridania (Stoll, 1782) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase). The longevity, pre-, post- and oviposition periods, fecundity and fertility of 15 couples was evaluated. The longevity of females (10.80 days) was not significantly higher than those of males (9.27 days). The mean durations of the pre, post and oviposition periods were 2.067, 0.600 and 8.133 days, respectively. The mean fecundity per female was 1,398 eggs …

Frequency And Distribution Of Extended Diapause In Nebraska Populations Of Diabrotica Barberi (Coleoptera: Chrysomelidae), Ryan W. Geisert, Lance J. Meinke

Department of Entomology: Faculty Publications

The frequency of extended diapause in populations of the northern corn rootworm, Diabrotica barberi Smith & Lawrence (Coleoptera: Chrysomelidae), was measured in eastern Nebraska. Adult collections were made during late summer in 2008 and 2009 from eight sites each year (seven sites were consistent over years). Eggs were obtained from 12 to 20 females per site and were held on moist soil under appropriate temperature profiles to facilitate egg survival, diapause development, and diapause termination. Percentage egg hatch was recorded after the first and second year for the 2008 and 2009 collections. Additional extended diapause expression was estimated for the …

Waveform Library For Chinch Bugs (Hemiptera: Heteroptera: Blissidae): Characterization Of Electrical Penetration Graph Waveforms At Multiple Input Impedances, Elaine A. Backus, Murugesan Rangasamy, Mitchell Stamm, Heather J. Mcauslane, Ron Cherry

Department of Entomology: Faculty Publications

Electrical penetration graph (EPG) monitoring has been used extensively to elucidate mechanisms of resistance in plants to insect herbivores with piercing-sucking mouthparts. Characterization of waveforms produced by insects during stylet probing is essential to the application of this technology. In the studies described herein, a four-channel Backus and Bennett AC-DC monitor was used to characterize EPG waveforms produced by adults of two economically important chinch bug species: southern chinch bug, Blissus insularis Barber, feeding on St. Augustinegrass, and western chinch bug, Blissus occiduus Barber, feeding on buffalograss. This is only the third time a heteropterans species has been recorded by …

Occurrence Of Entomopathogenic Fungi And Parasitic Nematodes On Spodoptera Frugiperda (Lepidoptera: Noctuidae) Larvae Collected In Central Chiapas, México, Ramiro E. Ruiz-Najera, Ramiro E. Ruiz-Estudillo, Juan M. Sanchez-Yanex, Jaime Molina-Ochoa, S. R. Skoda, Roberto Coutino-Ruiz, Rene Pinto-Ruiz, Francisco Guevara-Hernandez, John E. Foster

Department of Entomology: Faculty Publications

Fall armyworm larvae (FAW), Spodoptera frugiperda (J. E. Smith) were collected from whorl-stage corn, Zea mays (L.), between the V₂ and V₄ stages, in 22 localities of Central, Chiapas, México, called “La Frailesca” during late Jun 2009 to determine the occurrence of native entomopathogens and parasitic nematodes, and to determine the most parasitized instars. A total of 1,247 larvae were examined in search of native biological control agents. Overall total larval mortality was 16.36%. The percent larval mortality due to entomopathogens and parasitic nematodes was 12.99%. Hexamermis sp., probably albicans Siebold (Mermitha: Mermithidae) were isolated from 105 FAW …

Aquatic Macroinvertebrate Communities And Water Quality At Buffered And Non-Buffered Wetland Sites On Federal Waterfowl Production Areas In The Rainwater Basin, Nebraska, John R. Riens, Matt S. Schwarz, Fatima Mustafa, William Wyatt Hoback

Department of Entomology: Faculty Publications

Nebraska’s Rainwater Basin has an abundance of natural wetlands and is a focal point in the annual migration corridor used by millions of waterfowl and shorebirds. However, these wetlands are in a landscape dominated by agriculture and as a result, siltation and poor water quality are continual problems. We evaluated twelve wetland sites on federally managed Waterfowl Protection Areas from 2007 – 2009 for water quality, sediment quality, andmacroinvertebrate diversity. Six of the sites received agricultural runoff directly via culverts and drainage ditches (non-buffered sites) and six siteswere protected from agricultural runoff by a vegetated buffer (buffered sites). Mean total …

Role Of A Gamma-Aminobutryic Acid (Gaba) Receptor Mutation In The Evolution And Spread Of Diabrotica Virgifera Virgifera Resistance To Cyclodiene Insecticides, H. Wang, B. S. Coates, H. Chen, T. W. Sappington, T. Guillemaud, B. D. Siegfried

Department of Entomology: Faculty Publications

The western corn rootworm, Diabrotica virgifera virgifera, is a damaging pest of cultivated corn that was controlled by applications of cyclodiene insecticides from the late 1940s until resistance evolved ~10 years later. Range expansion from the western plains into eastern USA coincides with resistance development. An alanine to serine amino acid substitution within the Rdl subunit of the gamma-aminobutyric acid (GABA) receptor confers resistance to cyclodiene insecticides in many species. We found that the nonsynonymous single nucleotide polymorphism (SNP) G/T at the GABA receptor cDNA position 838 (G/T⁸³⁸) of D. v. virgifera resulted in the alanine to …

Towards The Elements Of Successful Insect Rnai, Jeffrey G. Scott, Kristin Michel, L. Bartholomay, Blair Siegfried, Wayne B. Hunter, Guy Smagghe, Kun Yan Zhu, Angela E. Douglas

Department of Entomology: Faculty Publications

RNA interference (RNAi), the sequence-specific suppression of gene expression, offers great opportunities for insect science, especially to analyze gene function, manage pest populations, and reduce disease pathogens. The accumulating body of literature on insect RNAi has revealed that the efficiency of RNAi varies between different species, the mode of RNAi delivery, and the genes being targeted. There is also variation in the duration of transcript suppression. At present, we have a limited capacity to predict the ideal experimental strategy for RNAi of a particular gene/insect because of our incomplete understanding of whether and how the RNAi signal is amplified and …

Estimating The Frequency Of Cry1f Resistance In Field Populations Of The European Corn Borer (Lepidoptera: Crambidae), Blair D. Siegfried, Murugesan Rangasamy, Haichuan Wang, Terence Spencer, Chirakkal V. Haridas, Brigitte Tenhumberg, Douglas V. Sumerford, Nicholas P. Storer

Department of Entomology: Faculty Publications

BACKGROUND: Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) have suppressed European corn borer populations and reduced the pest status of this insect throughout much of the US corn belt. A major assumption of the high-dose/refuge strategy proposed for insect resistancemanagement and Bt corn is that the frequency of resistance alleles is low so that resistant pests surviving exposure to Bt corn will be rare.

RESULTS: The frequency of resistance to the Cry1F Bt toxin was estimated using twodifferent screening tools andcompared with annual susceptibility monitoring based on diagnostic bioassays and LC₅₀ and EC₅₀ determinations. An …

Inheritance Of Cry1f Resistance, Crossresistance And Frequency Of Resistant Alleles In Spodoptera Frugiperda (Lepidoptera: Noctuidae), A. M. Vélez, T. A. Spencer, A. P. Alves, D. Moellenbeck, R. L. Meagher, H. Chirakkal, B. D. Siegfried

Department of Entomology: Faculty Publications

Transgenic maize, Zea maize L., expressing the Cry1F protein from Bacillus thuringiensis has been registered for Spodoptera frugiperda ( J. E. Smith) control since 2003. Unexpected damage to Cry1F maize was reported in 2006 in Puerto Rico and Cry1F resistance in S. frugiperda was documented. The inheritance of Cry1F resistance was characterized in a S. frugiperda resistant strain originating from Puerto Rico, which displayed >289-fold resistance to purified Cry1F. Concentration–response bioassays of reciprocal crosses of resistant and susceptible parental populations indicated that resistance is recessive and autosomal. Bioassays of the backcross of the F1 generation crossed with the resistant parental …

Colony Genetic Structure Of Reticulitermes Flavipes (Kollar) From Natural Populations In Nebraska, Abdul Hafiz Ab Majid, Shripat T. Kamble, Nicholas J. Miller

Department of Entomology: Faculty Publications

Genetic markers are a powerful tool to investigate the breeding structure and population genetics of subterranean termites. In this study, 1 0 - 2 0 subterranean termite workers, Reticulitermes flavipes (Kollar) were collected from colonies at 8 sites, separated by at least 200 m. Ten workers from each site were genotyped at 7 microsatellite loci. The data revealed that all 7 microsatellites were polymorphic with up to 6 alleles per locus. The frequency of most the common allele ranged from 0.11 - 0.60. Observed patterns of genetic variation within colonies revealed that most were the result of fusions of multiple …

Genetic Diversity And Relatedness Of The Mangrove Rhizophora Mangle L. (Rhizophoraceae) Using Amplified Fragment Polymorphism (Aflp) Among Locations In Florida, Usa And The Caribbean, M. Albrecht, K. M. Kneeland, E. Lindroth, John E. Foster

Department of Entomology: Faculty Publications

Rhizophora mangle L. is a widespread mangrove species in theWestern Hemisphere. Mangrove habitat loss and their importance to coastal and reef ecosystems make greater understanding of their genetic structure useful for conservation and management. An amplified fragment polymorphism (AFLP) analysis was performed on samples from Florida and the Caribbean to discover the genetic structure present. R. mangle had variable genetic diversity not related to latitude; P ranged 7 %–92 %. Some other factor, perhaps human impact, has caused low genetic diversity in some populations. Across Florida R. mangle populations varied in genetic diversity with less diversity (G_st=0.195) and …

Metabolic Engineering Of Raffinose-Family Oligosaccharides In The Phloem Reveals Alterations In Carbon Partitioning And Enhances Resistance To Green Peach Aphid, Te Cao, Ipsita Lahiri, Vijay Singh, Joe Louis, Jyoti Shah, Brian G. Ayre

Department of Entomology: Faculty Publications

Many plants employ energized loading strategies to accumulate osmotically-active solutes into the phloem of source organs to accentuate the hydrostatic pressure gradients that drive the flow of water, nutrients and signals from source to sinks. Proton-coupled symport of sugars from the apoplasm into the phloem symplasm is the best studied phloem-loading mechanism. As an alternative, numerous species use a polymer trapping mechanism to load through symplasm: sucrose enters the phloem through specialized plasmodesmata and is converted to raffinose-family oligosaccharides (RFOs) which accumulate because of their larger size. In this study, metabolic engineering was used to generate RFOs at the inception …

Dna Barcode Of Thief Ant Complex (Hymenoptera: Formicidae), Ralph B. Narain, Shripat T. Kamble, Thomas O. Powers, Timothy S. Harris

Department of Entomology: Faculty Publications

The thief ant, Solenopsis molesta (Say), a common nuisance species found throughout the United States is genetically related to red imported fire ants, S. invicta Buren. Therefore, its identification at the molecular level is very important. The deoxyribonucleic acid (DNA) barcoding, a recent technique was used to identify thief ant complex at species and subspecies levels using a short DNA sequence from the cytochrome oxidase subunit 1 (COI) mitochondrial region. The DNA from thief ants collected from 9 states was extracted using Qiagen's Gentra PUREGENE® DNA Isolation Kit. The polymerase chain reactions (PCR) were run on the extracted DNA to …

Bacillus Thuringiensis: Transgenic Crops, Julie A. Peterson, John J. Obrycki, James D. Harwood

Department of Entomology: Faculty Publications

Bacillus thuringiensis (Bt) crops, genetically modified to express insecticidal toxins that target key pests of corn, cotton, rice, potato, and other crops, have been rapidly adopted and have become dominant fixtures in agroecosystems throughout the world. Due to the constitutive nature of Bt toxin expression, insecticidal proteins may be found in nearly all plant tissues, presenting multiple sources for Bt toxins to enter the environment, thus creating complex direct and indirect pathways for non-target organisms to be exposed to insecticidal proteins. The environmental impacts of Bt crops have been widely debated, although both benefits and risks do exist. Benefits of …

Taxonomy And Biogeography Of The New Caledonian Species Of Xylopia L. (Annonaceae), David M. Johnson, Jérôme Munzinger, Julie A. Peterson, Nancy A. Murray

Department of Entomology: Faculty Publications

A taxonomic review of the New Caledonian representatives of the pantropical tree genus Xylopia L. (Annonaceae) is presented based on museum study of 157 collections. Distinctions are clarified among the four endemic species, two of them previously undescribed in flower and two others described in the literature from only the type collections. A key and species descriptions are presented. Xylopia pancheri Baill., the most frequently collected species, occurs in maquis environments with ultramafic rocks in the central and southern regions of the island, as well as on the Ile des Pins. Xylopia vieillardii Baill. is widespread in low elevation humid …

Non Target Effect Of Cry1 Ab And Cry Ab X Cry3 Bb1 Bt Transgenic Maize On Orius Insidiosus (Hemiptera: Anthocoridae) Abundance, Santiago A. Palizada, Difabachew K. Belay, Bamphitlhi Tiroesele, Fatima Mustafa, Muhammad Ullah, Thomas Hunt, Jaime Molina-Ochoa, S. R. Skoda, Pete L. Clark, John E. Foster

Department of Entomology: Faculty Publications

Non-target effects of Cry1Ab x CP4 EPSPS and Cry1Ab+Cry3Bb1×CP4 EPSPS Bt transgenic new maize hybrids on insidious flower bugs [Orius insidiosus (Say)] was studied in Nebraska (Mead, C lay Center, and Concord) during 2007 and 2008. The Bt effect was compared to CP4 EPSPS maize (isoline), conventional maize, and insecticide applications of permethrin (Pounce® 1.5G) and bifenthrin (Capture® 2EC) to control first and second generations of Ostrinia nubilalis (Hübner), respectively. Yellow sticky cards, visual observations, and destructive samplings were used to evaluate O. insidiosus abundance. The yellow sticky card data in 2007 showed that O. insidiosus abundance was lower …

Immature Stages Of Spodoptera Albula (Walker) (Lepidoptera: Noctuidae): Developmental Parameters And Host Plants, Débora G. Montezano, Alexandre Specht, Tarciso M. Bortolin, Edegar Fronza, Daniel Ricardo Sosa-Gómez, Vânia F. Roque-Specht, Patricia Pezzi, Priscila C. Luz, Neiva M. Barros

Department of Entomology: Faculty Publications

This study aimed to detail the temporal and morphological parameters of the immature stages of Spodoptera albula (Walker 1857) under controlled conditions (25 ± 1°C, 70 ± 10% RH and 14 hour photophase) and to gather information about their larval host plants. For this purpose, a new rearing method and artificial diet was employed and validated. The viability of the egg, larval, pupal and pre-pupal stages was 94.54, 97.33, 93.84 and 92.34%, respectively. The average duration of the egg, larval, pupal and pre-pupal stages was 4.14, 16.37, 1.69, and 9.34 days, respectively. During the larval stage, 80.85% of females and …

Comparative Binding Of Cry1ab And Cry1f Bacillus Thuringiensis Toxins To Brush Border Membrane Proteins From Ostrinia Nubilalis, Ostrinia Furnacalis And Diatraea Saccharalis (Lepidoptera: Crambidae) Midgut Tissue, Sek Yee Tan, Bonifacio F. Cayabyab, Edwin P. Alcantara, Fangneng Huang, Kanglai He, Kenneth Nickerson, Blair Siegfried

Department of Entomology: Faculty Publications

The European (Ostrinia nubilalis Hübner) and Asian corn borers (Ostrinia furnacalis Guenée) are closely related and display similar sensitivity to Cry1 toxins. In this study, we compared the binding patterns of Cry1Ab and Cry1F toxins between both Ostrinia spp., as well as the expression of putative cad­herin and aminopeptidase-N (APN)-like protein receptors. Additionally, cDNA sequences of these putative toxin receptors from both Ostrinia species were compared. Ligand blots for both species indicated a similar binding pattern for Cry1Ab with the strongest immunoreactive band at 260 kDa in both species. In addition, similar expression of the putative cadherin- and …

Current Known Range Of The Platte River Caddisfly, Ironoquia Plattensis, And Genetic Variability Among Populations From Three Nebraska Rivers, Lindsay A. Vivian, Michael Cavallaro, Kate Kneeland, Erica Lindroth, W. Wyatt Hoback, Kerri M. Farnsworth-Hoback, Robert R. Harms, John E. Foster

Department of Entomology: Faculty Publications

The Platte River caddisfly (Ironoquia plattensis Alexander and Whiles 2000) was recently described from a warm-water slough along the Platte River in central Nebraska and was considered abundant at the type locality. Surveys of 48 sites in 1999 and 2004 found eight additional sites with this species on the Platte River. The caddisfly was not found at the type locality in 2004 and one additional site in 2007, presumably because of drought conditions. Because of its apparent rarity and decline, the Platte River caddisfly is a Tier I species in Nebraska. For this project, surveys for the caddisfly were …

Mobilization Of Lipids And Fortification Of Cell Wall And Cuticle Are Important In Host Defense Against Hessian Fly, Chitvan Khajuria, Haiyan Wang, Xuming Liu, Shanda Wheeler, John C. Reese, Mustapha El Bouhssini, R. Jeff Whitworth, Ming-Shun Chen

Department of Entomology: Faculty Publications

Background: Wheat – Hessian fly interaction follows a typical gene-for-gene model. Hessian fly larvae die in wheat plants carrying an effective resistance gene, or thrive in susceptible plants that carry no effective resistance gene.

Results: Gene sets affected by Hessian fly attack in resistant plants were found to be very different from those in susceptible plants. Differential expression of gene sets was associated with differential accumulation of intermediates in defense pathways. Our results indicated that resources were rapidly mobilized in resistant plants for defense, including extensive membrane remodeling and release of lipids, sugar catabolism, and amino acid transport …

Unlinked Genetic Loci Control The Reduced Transcription Of Aminopeptidase N 1 And 3 In The European Corn Borer And Determine Tolerance To Bacillus Thuringiensis Cry1ab Toxin, Brad S. Coates, Douglas V. Sumerford, Blair Siegfried, Richard L. Hellmich, Craig A. Abel

Department of Entomology: Faculty Publications

Transgenic expression of Bacillus thuringiensis (Bt) crystalline (Cry) toxins by crop plants result in reduced insect feeding damage, but sustainability is threatened by the development of resistance traits in target insect populations. We investigated Bt toxin resistance trait in a laboratory colony of the European corn borer, Ostrinia nubilalis, selected for increased survival when exposed to Cry1Ab and correlated survival on Cry1Ab toxin with a constitutive~146.2 ± 17.3-fold reduction in midgut aminopeptidase N1 (apn1) transcript levels. A 7.1 ± 1.9-fold reduction apn3 transcript level was also correlated with Cry1Ab resistance. Quantitative trait locus (QTL) mapping identified a single major …

Amplified Fragment Length Polymorphism Used To Investigate Genetic Variability Of The Stable Fly (Diptera: Muscidae) Across North America, K. M. Kneeland, S. R. Skoda, John E. Foster

Department of Entomology: Faculty Publications

The stable fly, Stomoxys calcitrans (L.), is a cosmopolitan pest of livestock and humans. The pestiferous nature and painful bite cause stress to cattle and other animals. The stress and resulting avoidance behaviors manifest as reductions in weight gain or milk production in cattle; estimated annual economic loss in the United States exceeds US$2 billion. Understanding the population genetics of stable flies could provide information on their population dynamics, origins of outbreaks, and geographical patterns of insecticide resistance, resulting in a tactical advantage for developing management strategies. Previous studies, mostly on a local scale, reported a high level of gene …

Dietary Supplementation With Pollen Enhances Survival And Collembola Boosts Fitness Of A Web-Building Spider, Jason M. Schmidt, Julie A. Peterson, Jonathan Lundgren, James D. Harwood

Department of Entomology: Faculty Publications

Uncertainties exist about the value of non-prey food for predators that are commonly food-limited, and the dietary conditions where non-prey foods are beneficial for carnivorous species. Prior studies show that large quantities of pollen grains are intercepted in the webs of web-building spiders. We examined the nutritional benefits of pollen as a non-prey food for a common ground-dwelling, sheet web-building spider, Mermessus fradeorum (Berland) (Araneae: Linyphiidae). These predators were provided diets of prey or no prey in the presence and absence of pollen. Treatment effects were quantified by measuring predator body nutrient composition, survival, body size, and offspring production. Per …

Inter- And Intraspecific Identification Of The Screwworm, Cochliomyia Hominivorax, Using Random Amplified Polymorphic Dna-Polymerase Chain Reaction, Steven R. Skoda, James L. Figarola, Saowaluck Pornkulwat, John E. Foster

Department of Entomology: Faculty Publications

The screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae), is one of the most devastating arthropod pests of livestock in the Western Hemisphere. Early instars are very difficult to distinguish morphologically from several closely related blow fly species. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) markers were developed for identifying C. hominivorax from other wound inhabiting species. Forty decameric primers were screened; nine showed clear reproducible RAPD profiles suitable for distinguishing all life stages of C. hominivorax from 7 other species, including C. macellaria (Fabricius). The results from RAPD-PCR with field-collected samples of unknown first instars agreed with morphological identification that the …