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Full-Text Articles in Entomology

Efficacy Of Genetically Modified Bt Toxins Against Insects With Different Genetic Mechanisms Of Resistance, Bruce E. Tabashnik, Fangneng P. Huang, Mukti N. Ghimire, B. Rogers Leonard, Blair D. Siegfried, Murugesan Rangasamy, Yajun Yang, Yidong Wu, Linda J. Gahan, David G. Heckel, Alejandro Bravo, Mario Soberón Dec 2011

Efficacy Of Genetically Modified Bt Toxins Against Insects With Different Genetic Mechanisms Of Resistance, Bruce E. Tabashnik, Fangneng P. Huang, Mukti N. Ghimire, B. Rogers Leonard, Blair D. Siegfried, Murugesan Rangasamy, Yajun Yang, Yidong Wu, Linda J. Gahan, David G. Heckel, Alejandro Bravo, Mario Soberón

Department of Entomology: Faculty Publications

Transgenic crops that produce Bacillus thuringiensis (Bt) toxins are grown widely for pest control, but insect adaptation can reduce their efficacy. The genetically modified Bt toxins Cry1AbMod and Cry1AcMod were designed to counter insect resistance to native Bt toxins Cry1Ab and Cry1Ac. Previous results suggested that the modified toxins would be effective only if resistance was linked with mutations in genes encoding toxin-binding cadherin proteins. Here we report evidence from five major crop pests refuting this hypothesis. Relative to native toxins, the potency of modified toxins was > 350-fold higher against resistant strains of Plutella xylostella and Ostrinia nubilalis …


Cost-Effective Binomial Sequential Sampling Of Western Bean Cutworm, Striacosta Albicosta (Lepidoptera: Noctuidae), Egg Masses In Corn, S. Paula-Moraes, E. C. Burkness, Thomas E. Hunt, Robert Wright, Gary Hein, W. D. Hutchinson Dec 2011

Cost-Effective Binomial Sequential Sampling Of Western Bean Cutworm, Striacosta Albicosta (Lepidoptera: Noctuidae), Egg Masses In Corn, S. Paula-Moraes, E. C. Burkness, Thomas E. Hunt, Robert Wright, Gary Hein, W. D. Hutchinson

Department of Entomology: Faculty Publications

Striacosta albicosta (Smith) (Lepidoptera: Noctuidae), is a native pest of dry beans (Phaseolus vulgaris L.) and corn (Zea mays L.). As a result of larval feeding damage on corn ears, S. albicosta has a narrow treatment window; thus, early detection of the pest in the field is essential, and egg mass sampling has become a popular monitoring tool. Three action thresholds for field and sweet corn currently are used by crop consultants, including 4% of plants infested with egg masses on sweet corn in the silking-tasseling stage, 8% of plants infested with egg masses on field corn with …


Ecology And Management Of The Woolly Whitefly (Hemiptera: Aleyrodidae), A New Invasive Citrus Pest In Ethiopia, Difabachew K. Belay, Abebe Zewdu, John E. Foster Aug 2011

Ecology And Management Of The Woolly Whitefly (Hemiptera: Aleyrodidae), A New Invasive Citrus Pest In Ethiopia, Difabachew K. Belay, Abebe Zewdu, John E. Foster

Department of Entomology: Faculty Publications

Distribution and importance of woolly whitefly (Aleurothrixus floccosus) (Maskell) (Hemiptera: Aleyrodidae), was studied in Ethiopia with an evaluation of treatments against it. Results showed that the pest is distributed in most citrus-growing parts of the country equally infesting all types of citrus crops. Only one pupal parasitoid, Amitus sp., was recorded at Melkaoba. During 2006–2007, eight treatments gave better control of woolly whitefly compared with the control: endod (Phytolacca dodecandra L’Herit) berry extract, white oil 80%, neem oil, omo detergent soap, band application of gasoline, cyhalothrin (karate) 5% EC, selecron (profenofos) 500 EC, and rimon (novaluron) 10 EC. …


Induced Resistance Studied In Maize With The Fall Armyworm, Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) And The Chemical Inducer Actigard, Stephen D. Danielson May 2011

Induced Resistance Studied In Maize With The Fall Armyworm, Spodoptera Frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) And The Chemical Inducer Actigard, Stephen D. Danielson

Department of Entomology: Faculty Publications

Induced resistance has been defined as the "qualitative or quantitative enhancement of a plant's defense mechanisms against pests in response to extrinsic physical or chemical stimuli." (Kogan and Paxton, 1983). Physical stimuli can include infection by a pathogenic organism (Jorgensen et al, 1996; Morris et al, 1998) and feeding by insects (Felton and Eichenseer, 1999). Chemical stimuli include such organic compounds as salicylic acid (Hammerschmidt and Smith-Becker, 1999), jasmonic acid (Staswick and Lehman, 1999), and the commercially available Actigard® 50WG (Tally et al., 1999) (Syngenta Crop Protection, P.O. Box 18300, Greensboro, NC 27419). Actigard® 50WG is registered in the U.S. …


Fitness Of Diabrotica Barberi, Diabrotica Longicornis, And Their Hybrids (Coleoptera: Chrysomelidae), Laura A. Campbell, Lance J. Meinke May 2011

Fitness Of Diabrotica Barberi, Diabrotica Longicornis, And Their Hybrids (Coleoptera: Chrysomelidae), Laura A. Campbell, Lance J. Meinke

Department of Entomology: Faculty Publications

Diabrotica barberi Smith & Lawrence, the northern corn rootworm, and Diabrotica longicornis (Say) (Coleoptera: Chrysomelidae), are currently recognized as closely related chrysomelid species. Hybridization has been proposed to occur between them, although the viability of hybrids has never been tested. The objective of this study was to assess life-history parameters of D. barberi,D. longicornis, and their hybrids under laboratory conditions to examine the potential for field hybridization. D. barberi and D. longicornis were collected in allopatry and were used to create lab colonies. Parental species were crossed to obtain F1 hybrids, F2 hybrids, and backcrosses to either parental species. …


Draft Genome Of The Red Harvester Ant Pogonomyrmex Barbatus, Chris R. Smith, Christopher D. Smith, Hugh M. Robertson, Martin Helmkampf, Aleksey Zimin, Mark Yandall, Carson Holt, Hao Hu, Ehab Abouheif, Richard Benton, Elizabeth Cash, Vincent Croset, Cameron R. Currie, Eran Elhaik, Christine G. Elsik, Marie-Julie Favé, Vilaiwan Fernandes, Joshua D. Gibson, Dan Graur, Wulfila Gronenberg, Kirk J. Grubbs, Darren E. Hagen, Ana Sofia Ibarraran Viniegra, Brian R. Johnson, Reed M. Johnson, Abderrahman Khila, Jay W. Kim, Kaitlyn A, Mathis, Monica C. Munoz-Torres, Marguerite C. Murphy, Julie A. Mustard, Rin Nakamura, Oliver Niehuis, Surabhi Nigam, Rick P. Overson, Jennifer E. Placek, Rajendhran Rajakumar, Justin T. Reese, Garret Suen, Shu Tao, Candice W. Torres, Neil D. Tsutsui, Lumi Viljakainen, Florian Wolschin, Jürgen Gadau Apr 2011

Draft Genome Of The Red Harvester Ant Pogonomyrmex Barbatus, Chris R. Smith, Christopher D. Smith, Hugh M. Robertson, Martin Helmkampf, Aleksey Zimin, Mark Yandall, Carson Holt, Hao Hu, Ehab Abouheif, Richard Benton, Elizabeth Cash, Vincent Croset, Cameron R. Currie, Eran Elhaik, Christine G. Elsik, Marie-Julie Favé, Vilaiwan Fernandes, Joshua D. Gibson, Dan Graur, Wulfila Gronenberg, Kirk J. Grubbs, Darren E. Hagen, Ana Sofia Ibarraran Viniegra, Brian R. Johnson, Reed M. Johnson, Abderrahman Khila, Jay W. Kim, Kaitlyn A, Mathis, Monica C. Munoz-Torres, Marguerite C. Murphy, Julie A. Mustard, Rin Nakamura, Oliver Niehuis, Surabhi Nigam, Rick P. Overson, Jennifer E. Placek, Rajendhran Rajakumar, Justin T. Reese, Garret Suen, Shu Tao, Candice W. Torres, Neil D. Tsutsui, Lumi Viljakainen, Florian Wolschin, Jürgen Gadau

Department of Entomology: Faculty Publications

We report the draft genome sequence of the red harvester ant, Pogonomyrmex barbatus. The genome was sequenced using 454 pyrosequencing, and the current assembly and annotation were completed in less than 1 y. Analyses of conserved gene groups (more than 1,200 manually annotated genes to date) suggest a high-quality assembly and annotation comparable to recently sequenced insect genomes using Sanger sequencing. The red harvester ant is a model for studying reproductive division of labor, phenotypic plasticity, and sociogenomics. Although the genome of P. barbatus is similar to other sequenced hymenopterans (Apis mellifera and Nasonia vitripennis) in GC …


Characterization Of Olfactory Sensilla Of Stomoxys Calcitrans And Electrophysiological Responses To Odorant Compounds Associated With Hosts And Oviposition Media, K. Tangtrakulwanich, Han Chen, Frederick P. Baxendale, Gary J. Brewer, J. J. Zhu Jan 2011

Characterization Of Olfactory Sensilla Of Stomoxys Calcitrans And Electrophysiological Responses To Odorant Compounds Associated With Hosts And Oviposition Media, K. Tangtrakulwanich, Han Chen, Frederick P. Baxendale, Gary J. Brewer, J. J. Zhu

Department of Entomology: Faculty Publications

Stable flies, Stomoxys calcitrans L. (Diptera: Muscidae), are economically important biting flies that have caused billions of dollars in losses in the livestock industry. Field monitoring studies have indicated that olfaction plays an important role in host location. To further our understanding of stable fly olfaction, we examined the antennal morphology of adults using scanning electron microscopy techniques. Four major types of sensillum were found and classified as: (a) basiconic sensilla; (b) trichoid sensilla with three subtypes; (c) clavate sensilla, and (d) coeloconic sensilla. No significant differences between male and female flies in abundances (total numbers) of these sensillum types …


Field Introgression Of Diabrotica Barberi And Diabrotica Longicornis (Coleoptera: Chrysomelidae) Based On Genetic And Morphological Characters, Laura A. Campbell, Thomas L. Clark, Pete L. Clark, Lance Meinke, John E. Foster Jan 2011

Field Introgression Of Diabrotica Barberi And Diabrotica Longicornis (Coleoptera: Chrysomelidae) Based On Genetic And Morphological Characters, Laura A. Campbell, Thomas L. Clark, Pete L. Clark, Lance Meinke, John E. Foster

Department of Entomology: Faculty Publications

Diabrotica barberi Smith & Lawrence and Diabrotica longicornis (Say) (Coleoptera: Chrysomelidae) are considered to be sister species, and it has been proposed that the two species may hybridize under field conditions. The objective of this study was to examine genetic and morphological characters of D. barberi and D. longicornis for evidence of field introgression. Both species were collected from sympatric and allopatric areas. Amplified fragment length polymorphisms and morphological characters (color and head capsule width) were used to examine variation within and among populations of D. barberi and D. longicornis. Relatively little of the overall …


Genetic Variation And Inheritance Of Diapause Induction In Two Distinct Voltine Ecotypes Of Ostrinia Nubilalis (Lepidoptera: Crambidae), Cengis Ikten, Steven R. Skoda, Thomas E. Hunt, Jaime Molina-Ochoa, John E. Foster Jan 2011

Genetic Variation And Inheritance Of Diapause Induction In Two Distinct Voltine Ecotypes Of Ostrinia Nubilalis (Lepidoptera: Crambidae), Cengis Ikten, Steven R. Skoda, Thomas E. Hunt, Jaime Molina-Ochoa, John E. Foster

Department of Entomology: Faculty Publications

European corn borer, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae), displays a larval diapause in response to short photoperiods and is adapted to a variety of local conditions throughout North America. Hence, the effective photoperiod inducing larval diapause will differ among geographic ecotypes. This study considers the inheritance of photoperiodic larval diapause induction by hybridization and backcrossing two latitudinally distinct ecotypes of the European corn borer collected between 41° N, 96° W and 48° N, 96° W and under a range of photoperiods representative of their respective locations: from 14:10 to 16:8 (L:D) h. The ecotype adapted to a bivoltine habitat (southeastern …


Dose–Response Relationships Of Clothianidin, Imidacloprid, And Thiamethoxam To Blissus Occiduus (Hemiptera: Blissidae), M. D. Stamm, Frederick P. Baxendale, Tiffany Heng-Moss, Blair D. Siegfried, Erin E. Blankenship, Roch E. Gaussoin Jan 2011

Dose–Response Relationships Of Clothianidin, Imidacloprid, And Thiamethoxam To Blissus Occiduus (Hemiptera: Blissidae), M. D. Stamm, Frederick P. Baxendale, Tiffany Heng-Moss, Blair D. Siegfried, Erin E. Blankenship, Roch E. Gaussoin

Department of Entomology: Faculty Publications

The western chinch bug, Blissus occiduus Barber (Hemiptera: Blissidae), has emerged as a serious pest of buffalograss, Buchloë dactyloides (Nuttall) Engelmann. In general, neonicotinoid insecticides effectively control a variety of turfgrass insects, particularly phloem-feeding pests. However, because of well documented inconsistencies in control, these compounds are generally not recommended for chinch bugs. This study was designed to document the contact and systemic toxicity of three neonicotinoid insecticides (clothianidin, imidacloprid, and thiamethoxam) to B. occiduus. In contact bioassays, thiamethoxam was ~20-fold less toxic than clothianidin or imidacloprid to B. occiduus nymphs and three-fold more toxic to adults. In adult systemic …


Comparative Susceptibility Of Ostrinia Furnacalis, Ostrinia Nubilalis, And Diatraea Saccharalis (Lepidoptera: Crambidae) To Bacillus Thuringiensis Cry1 Toxins, S. Y. Tan, B. F. Cayabyab, E. P. Alcantara, Y. B. Ibrahim, Fangneng Huang, Erin E. Blankenship, Blair D. Siegfried Jan 2011

Comparative Susceptibility Of Ostrinia Furnacalis, Ostrinia Nubilalis, And Diatraea Saccharalis (Lepidoptera: Crambidae) To Bacillus Thuringiensis Cry1 Toxins, S. Y. Tan, B. F. Cayabyab, E. P. Alcantara, Y. B. Ibrahim, Fangneng Huang, Erin E. Blankenship, Blair D. Siegfried

Department of Entomology: Faculty Publications

Transgenic corn hybrids that express toxins from Bacillus thuringiensis (Bt) are highly effective against the European corn borer, Ostrinia nubilalis (Hübner), and the closely related Asian corn borer, Ostrinia furnacalis (Guenée). Since the registration of Bt corn hybrids in the U.S. in 1996, there has been a great deal of information generated on O. nubilalis. However, relatively little information exists for O. furnacalis. To help determine whether the information generated for O. nubilalis can be leveraged for decisions regarding the use of transgenic Bt corn against O. furnacalis, experiments were designed to determine whether the pattern of sensitivity …


Contact And Fumigant Toxicity Of A Botanical-Based Feeding Deterrent Of The Stable Fly, Stomoxys Calcitrans (Diptera: Muscidae), Junwei J. Zhu, Andrew Y. Li, Sara Pritchard, Khanobporn Tangtrakulwanich, Frederick P. Baxendale, Gary Brewer Jan 2011

Contact And Fumigant Toxicity Of A Botanical-Based Feeding Deterrent Of The Stable Fly, Stomoxys Calcitrans (Diptera: Muscidae), Junwei J. Zhu, Andrew Y. Li, Sara Pritchard, Khanobporn Tangtrakulwanich, Frederick P. Baxendale, Gary Brewer

Department of Entomology: Faculty Publications

The stable fly, Stomoxys calcitrans (L.), has been considered one of the most serious biting flies of confined and pastured livestock. The economic losses caused by the stable fly to the cattle industry in the United States exceed $2 billion annually. Current practices for managing stable flies using insecticides provide only marginal control. Insecticide resistance has also been recently reported in stable flies. The present study reports the use of plant-based insecticides, for example, essential oils, as alternatives for managing this fly pest. The toxicity of several plant essential oils and selected ingredient compounds was evaluated by contact and fumigant …


Evaluation Of Buffalograss Leaf Pubescence And Its Effect On Resistance To Mealybugs (Hemiptera: Pseudococcidae), Jennifer M. Johnson-Cicalese, Frederick P. Baxendale, Terrance P. Riordan, Tiffany Heng-Moss, Lisa Baird Jan 2011

Evaluation Of Buffalograss Leaf Pubescence And Its Effect On Resistance To Mealybugs (Hemiptera: Pseudococcidae), Jennifer M. Johnson-Cicalese, Frederick P. Baxendale, Terrance P. Riordan, Tiffany Heng-Moss, Lisa Baird

Department of Entomology: Faculty Publications

Considerable progress has been made in improving the turfgrass characteristics of buffalograss, Buchloë dactyloides (Nutt) Engelm, a native North American grass species with low maintenance requirements (Riordan et al., 1993). Two mealybugs, Tridiscus sporoboli (Cockerell) and Trionymus sp. (Hemiptera: Pseudococcidae) have emerged as buffalograss pests (Baxendale et al., 1994). Mealybugs have been associated with buffalograss stands throughout Nebraska (Baxendale et al., 1994), as well as in Texas and Arizona. Unfortunately, the Pseudococcidae are poorly described and species identification requires extensive specimen preparation (Ferris, 1950, 1953). Buffalograss mealybugs have an oblong, pale purple-grey, membranous body, ranging in length from 0.2 …


Phenology Of Stable Fly (Diptera: Muscidae) Larvae In Round Bale Hay Feeding Sites In Eastern Nebraska, David B. Taylor, Dennis R. Berkebile Jan 2011

Phenology Of Stable Fly (Diptera: Muscidae) Larvae In Round Bale Hay Feeding Sites In Eastern Nebraska, David B. Taylor, Dennis R. Berkebile

Department of Entomology: Faculty Publications

The temporal and spatial patterns of adult stable fly, Stomoxys calcitrans (L.), emergence from six sites where large round baled hay had been provided to pasture cattle as winter feed were studied using emergence traps. The substrate at these sites, consisting of waste hay mixed with bovine manure and urine, provided an excellent developmental habitat for immature stable flies. Stable flies were the most frequently collected fly emerging from these sites with a yearly average of 1,581 emerging per square meter. Stable fly emergence from these sites began in early May (235 annual accumulated Day-Degree 10°C [DD10]), peaked …


A Single Major Qtl Controls Expression Of Larval Cry1f Resistance Trait In Ostrinia Nubilalis (Lepidoptera: Crambidae) And Is Independent Of Midgut Receptor Genes, Brad S. Coates, Douglas V. Sumerford, Miriam D. Lopez, Haichuan Wang, Lisa M. Fraser, Jeremy A. Kroemer, Terrence Spencer, Kyung S. Kim, Craig A. Abel, Richard L. Hellmich, Blair D. Siegfried Jan 2011

A Single Major Qtl Controls Expression Of Larval Cry1f Resistance Trait In Ostrinia Nubilalis (Lepidoptera: Crambidae) And Is Independent Of Midgut Receptor Genes, Brad S. Coates, Douglas V. Sumerford, Miriam D. Lopez, Haichuan Wang, Lisa M. Fraser, Jeremy A. Kroemer, Terrence Spencer, Kyung S. Kim, Craig A. Abel, Richard L. Hellmich, Blair D. Siegfried

Department of Entomology: Faculty Publications

The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is an introduced crop pest in North America that causes major damage to corn and reduces yield of food, feed, and biofuel materials. The Cry1F toxin from Bacillus thuringiensis (Bt) expressed in transgenic hybrid corn is highly toxic to O. nubilalis larvae and effective in minimizing feeding damage. A laboratory colony of O. nubilalis was selected for high levels of Cry1F resistance ([12,000-fold compared to susceptible larvae) and is capable of survival on transgenic hybrid corn. Genetic linkage maps with segregating AFLP markers show that the Cry1F resistance trait is controlled by …


Identification Of A Novel Aminopeptidase P-Like Gene (Onapp) Possibly Involved In Bt Toxicity And Resistance In A Major Corn Pest (Ostrinia Nubilalis), Chitvan Khajuria, Lawrent L. Buschman, Ming-Shun Chen, Blair D. Siegfried, Kun Yan Zhu Jan 2011

Identification Of A Novel Aminopeptidase P-Like Gene (Onapp) Possibly Involved In Bt Toxicity And Resistance In A Major Corn Pest (Ostrinia Nubilalis), Chitvan Khajuria, Lawrent L. Buschman, Ming-Shun Chen, Blair D. Siegfried, Kun Yan Zhu

Department of Entomology: Faculty Publications

Studies to understand the Bacillus thuringiensis (Bt) resistance mechanism in European corn borer (ECB, Ostrinia nubilalis) suggest that resistance may be due to changes in the midgut-specific Bt toxin receptor. In this study, we identified 10 aminopeptidase-like genes, which have previously been identified as putative Bt toxin receptors in other insects and examined their expression in relation to Cry1Ab toxicity and resistance. Expression analysis for the 10 aminopeptidase-like genes revealed that most of these genes were expressed predominantly in the larval midgut, but there was no difference in the expression of these genes in Cry1Ab resistant and susceptible strains. …


Environmental Impact And Cost Benefit Analysis Of Biological Control Application, Jaime Molina-Ochoa, John E. Foster Jan 2011

Environmental Impact And Cost Benefit Analysis Of Biological Control Application, Jaime Molina-Ochoa, John E. Foster

Department of Entomology: Faculty Publications

The implications and interactions of the application of biological control agents in the environment, as well as the risks included by the introduction of exotic natural enemies are briefly reviewed. Description of the role of resistance or quality of the host plant to insect pests, and their interaction with biocontrol agents is provided. A need to increase applications or find new alternatives and environmental impact towards non target insects, and the real cost of its use against the benefits is discussed.


Interactions Of Transgenic Bacillus Thuringiensis Insecticidal Crops With Spiders (Araneae), Julie A. Peterson, Jonathan Lundgren, James D. Harwood Jan 2011

Interactions Of Transgenic Bacillus Thuringiensis Insecticidal Crops With Spiders (Araneae), Julie A. Peterson, Jonathan Lundgren, James D. Harwood

Department of Entomology: Faculty Publications

Genetically modified crops expressing insecticidal proteins from Bacillus thuringiensis (Bt) have dramatically increased in acreage since their introduction in the mid-1990’s. Although the insecticidal mechanisms of Bt target specific pests, concerns persist regarding direct and indirect effects on non-target organisms. In the field, spiders may be exposed to Bt toxins via multiple routes, including phytophagy and pollenivory, consumption of Bt-containing prey, and soil exudates in the detrital food web. Beyond direct toxicity, Bt crops may also have indirect impacts, including pleiotropic and preymediated effects. Here, we comprehensively review the literature and use meta-analyses to reveal that foliar spider abundance is …