Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
-
- Induced resistance (3)
- Soybean (3)
- Bean leaf beetle (2)
- Chemical inducer (2)
- Diabrotica (2)
-
- Ostrinia nubilalis (2)
- Resistance (2)
- Resistance management (2)
- Rootworms (2)
- AChE (1)
- Acalymma (1)
- Actigard (1)
- Actigard. (1)
- Aphididae (1)
- Bacillus thuringiensis (1)
- Bacterial infection (1)
- Bird cherry-oat aphid (1)
- Blattella germanica (1)
- Bt corn (1)
- CYP4 (1)
- Carotenoids (1)
- Catalase (1)
- Cattle (1)
- Chlorophyllase (1)
- Chlorophylls a and b (1)
- Chlorpyrifos (1)
- Cochliomyia hominivorax (1)
- Corn (1)
- Cross-resistance (1)
- Cryopreservation (1)
Articles 1 - 27 of 27
Full-Text Articles in Life Sciences
Chronic Exposure Of The European Corn Borer (Lepidoptera: Crambidae) To Cry1ab Bacillus Thuringiensis Toxin, Josette Chafaux, Maryvonne Seguin, Jeffrey J. Swanson, Denis Bourguet, Blair D. Siegfried
Chronic Exposure Of The European Corn Borer (Lepidoptera: Crambidae) To Cry1ab Bacillus Thuringiensis Toxin, Josette Chafaux, Maryvonne Seguin, Jeffrey J. Swanson, Denis Bourguet, Blair D. Siegfried
Department of Entomology: Faculty Publications
Transgenic corn expressing the insecticidal toxin from Bacillus thuringiensis Berliner is gaining support as an effective control technology for use against lepidopteran pests, particularly European corn borer, Ostrinia nubilalis Hubner (Lepidoptera: Crambidae). However, there is concern that widespread adoption of transgenic plants will rapidly lead to B. thuringiensis toxin resistance. Thus, long-term selection of O. nubilalis populations with the Cry1Ab B. thuringiensis toxin has been undertaken in several laboratories in the United States and in Europe. We present results from two independent selection experiments performed in laboratories at the University of Nebraska and at the Institut National de la Recherche …
Resistance Of Commercial Hybrids And Lines Of Sorghum, Sorghum Bicolor (L.) Moench., To Diatraea Saccharalis (Fabr.) (Lepidoptera: Pyralidae), Jose M. Waquil, Jose A. S. Rodrigues, Fredolino G. Santos, Alexandre S. Ferreira, Francys M. F. Vilella, John E. Foster
Resistance Of Commercial Hybrids And Lines Of Sorghum, Sorghum Bicolor (L.) Moench., To Diatraea Saccharalis (Fabr.) (Lepidoptera: Pyralidae), Jose M. Waquil, Jose A. S. Rodrigues, Fredolino G. Santos, Alexandre S. Ferreira, Francys M. F. Vilella, John E. Foster
Department of Entomology: Faculty Publications
Commercial sorghum hybrids and Embrapa’s lines were evaluated regarding resistance to sugarcane borer. Two field experiments were conducted in Sete Lagoas, MG, under natural infestation, during the second cropping season in a randomized complete block with 3 replicates. The plants were evaluated regarding to stand, maturity cycle, plant height, and number of broken or lodging stalks and yield. The borer incidence, number of galleries, number of healthy and damaged nodes were also evaluated to calculate the Infestation Index and Intensity Infestation Index. Among the commercial sorghum hybrids, Br 304 and CMSXS 9701 were the least infested wile Z 732 and …
Identification Of Screwworms, Cochliomyia Hominivorax (Coquerel) (Diptera: Calliphoridae), With A Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay (Mab-Elisa), J. L. Figarola, Steven R. Skoda, Dennis R. Berkebile, John E. Foster
Identification Of Screwworms, Cochliomyia Hominivorax (Coquerel) (Diptera: Calliphoridae), With A Monoclonal Antibody-Based Enzyme-Linked Immunosorbent Assay (Mab-Elisa), J. L. Figarola, Steven R. Skoda, Dennis R. Berkebile, John E. Foster
Department of Entomology: Faculty Publications
Myiasis caused by screwworms, Cochliomyia hominivorax (Coquerel), is devastating to warmblooded animals and economically important to livestock producers. It is difficult to distinguish these pests, immature screwworms, from immatures of other non-pest fly species that often occur in animal wounds; it would be helpful to have tools available that do not rely on morphological characteristics. We developed twomonoclonal antibodies (MAbs), highly specific for the screwworm, and used them in an enzyme-linked immunosorbent assay (MAb-ELISA), that differentiated screwworm eggs, larvae, pupae, and adults from those of the closely related secondary screwworm, C. macellaria (Fabricius) as well as Phormia regina (Meigen), Phaenicia …
Transgenic Insecticidal Corn: The Agronomic And Ecological Rationale For Its Use, Eldon E. Ortman, B. Dean Barry, Laurent L. Buschman, Dennis D. Calvin, Janet Carpenter, Galen P. Dively, John E. Foster, Billy W. Fuller, Richard L. Hellmich, Randall A. Higgens, Thomas E. Hunt, Gary P. Munkvold, Kenneth R. Ostlie, Marlin E. Rice, Richard T. Rousch, Mark K. Sears, Anthony M. Shelton, Blair D. Siegfried, Phillip E. Sloderbeck, Kevin L. Steffey, F. Tom Turpin, John L. Wedberg
Transgenic Insecticidal Corn: The Agronomic And Ecological Rationale For Its Use, Eldon E. Ortman, B. Dean Barry, Laurent L. Buschman, Dennis D. Calvin, Janet Carpenter, Galen P. Dively, John E. Foster, Billy W. Fuller, Richard L. Hellmich, Randall A. Higgens, Thomas E. Hunt, Gary P. Munkvold, Kenneth R. Ostlie, Marlin E. Rice, Richard T. Rousch, Mark K. Sears, Anthony M. Shelton, Blair D. Siegfried, Phillip E. Sloderbeck, Kevin L. Steffey, F. Tom Turpin, John L. Wedberg
Department of Entomology: Faculty Publications
We agree with Obrycki et al. (2001) that a broad-based ecological approach for new pest management technologies is desirable, but we unanimously and strongly disagree with some of their assumptions and conclusions about Bt corn. Bt corn is corn that has been genetically engineered to produce insecticidal proteins from the bacterium Bacillus thuringiensis. Because Bt corn is important for effective and ecologically sound management of lepidopteran pests of corn,we provide here relevant data, some of which is new, to help clarify the issues raised by Obrycki et al. (2001). Obrycki et al. (2001), citing Barry and Darrah (1991), claim that …
Monarch Larvae Sensitivity To Bacillus Thuringiensis Purified Proteins And Pollen, Richard L. Hellmich, Blair D. Siegfried, Mark K. Sears, Diane E. Stanley-Horn, Michael J. Daniels, Heather R. Mattila, Terrence A. Spencer, Keith J. Bidne, Leslie C. Lewis
Monarch Larvae Sensitivity To Bacillus Thuringiensis Purified Proteins And Pollen, Richard L. Hellmich, Blair D. Siegfried, Mark K. Sears, Diane E. Stanley-Horn, Michael J. Daniels, Heather R. Mattila, Terrence A. Spencer, Keith J. Bidne, Leslie C. Lewis
Department of Entomology: Faculty Publications
Laboratory tests were conducted to establish the relative toxicity of Bacillus thuringiensis (Bt) toxins and pollen from Bt corn to monarch larvae. Toxins tested included Cry1Ab, Cry1Ac, Cry9C, and Cry1F. Three methods were used: (i) purified toxins incorporated into artificial diet, (ii) pollen collected from Bt corn hybrids applied directly to milkweed leaf discs, and (iii) Bt pollen contaminated with corn tassel material applied directly to milkweed leaf discs. Bioassays of purified Bt toxins indicate that Cry9C and Cry1F proteins are relatively nontoxic to monarch first instars, whereas first instars are sensitive to Cry1Ab and Cry1Ac proteins. Older instars were …
Corn Pollen Deposition On Milkweeds In And Near Cornfields, John M. Pleasants, Richard L. Hellmich, Galen P. Dively, Mark K. Sears, Diane E. Stanley-Horn, Heather R. Mattila, John E. Foster, Peter Clark, Gretchen D. Jones
Corn Pollen Deposition On Milkweeds In And Near Cornfields, John M. Pleasants, Richard L. Hellmich, Galen P. Dively, Mark K. Sears, Diane E. Stanley-Horn, Heather R. Mattila, John E. Foster, Peter Clark, Gretchen D. Jones
Department of Entomology: Faculty Publications
The density of corn pollen on leaves of milkweed plants inside and outside of cornfields was measured in several studies from different localities. The purpose was to obtain a representative picture of naturally occurring pollen densities to provide a perspective for laboratory and field studies of monarch larvae feeding on milkweed leaves with Bt corn pollen. Pollen density was highest (average 170.6 grains per cm2) inside the cornfield and was progressively lower from the field edge outward, falling to 14.2 grains per cm2 at 2 m. Inside the cornfield, and for each distance from the field edge, …
Impact Of Bt Corn Pollen On Monarch Butterfly Populations: A Risk Assessment, Mark K. Sears, Richard L. Hellmich, Diane L. Stanley-Horn, Karen S. Oberhauser, John M. Pleasants, Heather R. Mattila, Blair D. Siegfried, Galen P. Dively
Impact Of Bt Corn Pollen On Monarch Butterfly Populations: A Risk Assessment, Mark K. Sears, Richard L. Hellmich, Diane L. Stanley-Horn, Karen S. Oberhauser, John M. Pleasants, Heather R. Mattila, Blair D. Siegfried, Galen P. Dively
Department of Entomology: Faculty Publications
A collaborative research effort by scientists in several states and in Canada has produced information to develop a formal risk assessment of the impact of Bt corn on monarch butterfly (Danaus plexippus) populations. Information was sought on the acute toxic effects of Bt corn pollen and the degree to which monarch larvae would be exposed to toxic amounts of Bt pollen on its host plant, the common milkweed, Asclepias syriaca, found in and around cornfields. Expression of Cry proteins, the active toxicant found in Bt corn tissues, differed among hybrids, and especially so in the concentrations found …
Monarch Larvae Sensitivity To Bacillus Thuringiensis Purified Proteins And Pollen, Richard L. Hellmich, Blair Siegfried, Mark K. Sears, Diane E. Stanley-Horn, Michael J. Daniels, Heather R. Matilla, Terrence A. Spencer, Keith G. Bidne, Leslie C. Lewis
Monarch Larvae Sensitivity To Bacillus Thuringiensis Purified Proteins And Pollen, Richard L. Hellmich, Blair Siegfried, Mark K. Sears, Diane E. Stanley-Horn, Michael J. Daniels, Heather R. Matilla, Terrence A. Spencer, Keith G. Bidne, Leslie C. Lewis
Department of Entomology: Faculty Publications
Laboratory tests were conducted to establish the relative toxicity of Bacillus thuringiensis (Bt) toxins and pollen from Bt corn to monarch larvae. Toxins tested included Cry1Ab, Cry1Ac, Cry9C, and Cry1F. Three methods were used: (i) purified toxins incorporated into artificial diet, (ii) pollen collected from Bt corn hybrids applied directly to milkweed leaf discs, and (iii) Bt pollen contaminated with corn tassel material applied directly to milkweed leaf discs. Bioassays of purified Bt toxins indicate that Cry9C and Cry1F proteins are relatively nontoxic to monarch first instars, whereas first instars are sensitive to Cry1Ab and Cry1Ac proteins. Older …
Lnduced Resistance To Bean Leaf Beetle (Coleoptera: Chrysomelidae) In Soybean, P. Srinivas, Stephen D. Danielson, C. Michael Smith, John E. Foster
Lnduced Resistance To Bean Leaf Beetle (Coleoptera: Chrysomelidae) In Soybean, P. Srinivas, Stephen D. Danielson, C. Michael Smith, John E. Foster
Department of Entomology: Faculty Publications
Induced resistance in soybean, Glycine max (L.) Merrill, to the bean leaf beetle, Cerotoma trifurcata (Forster), was investigated in greenhouse experiments using the treatments of mechanical injury, a chemical inducer (ActigardrM, Novartis Crop Protection lnc., Greensboro, NC) and defoliation by the bean leaf beetle and the soybean looper, Pseudoplusia includens (Walker). Experiments were conducted on soybean Pl 227687, two soybean cultivars (Colfax and Williams 82) and a soybean germplasm line (HC95-24MB). Dual-choice feeding-preference tests with bean leaf beetle adults were used to assess induced resistance. Adult beetles were collected from soybean fields 2 to 5 d prior to the feeding …
In Vitro Enzymatic Chlorophyll Catabolism In Wheat Elicited By Cereal Aphid Feeding, Xinzhi Ni, Sharron S. Quisenberry, John P. Markwell, Tiffany Heng-Moss, Leon G. Higley, Frederick P. Baxendale, Gautam Sarath, Robert Klucas
In Vitro Enzymatic Chlorophyll Catabolism In Wheat Elicited By Cereal Aphid Feeding, Xinzhi Ni, Sharron S. Quisenberry, John P. Markwell, Tiffany Heng-Moss, Leon G. Higley, Frederick P. Baxendale, Gautam Sarath, Robert Klucas
Department of Entomology: Faculty Publications
Chlorophyll degradation is a complex phenomenon that often accompanies insect feeding damage to plants. Loss of chlorophyll can be initiated by several reactions, including oxidative bleaching, chlorophyllase activity, and Mg-dechelatase activity. Extracts from the Russian wheat aphid [Diuraphis noxia (Mordvilko)], the bird cherry-oat aphid [Rhopalosiphum padi (L.)], and aphid-infested and uninfested wheat plants were assayed in vitro for activities involved in chlorophyll degradation. Although the initial infestation was the same (10 apterous adults) for both aphid species, D. noxia weight was significantly higher than R. padi after feeding for 12 days. Consequently, D. noxia feeding caused greater fresh …
Cryopreservation Of Embryos Of The New World Screwworm Cochliomyia Hominivorax (Diptera: Calliphoridae), R.A. Leopold, W.B. Wang, Dennis Berkebile, T.P. Freeman
Cryopreservation Of Embryos Of The New World Screwworm Cochliomyia Hominivorax (Diptera: Calliphoridae), R.A. Leopold, W.B. Wang, Dennis Berkebile, T.P. Freeman
Department of Entomology: Faculty Publications
A method for cryopreserving embryos of the screwworm, Cochliomyia hominivorax (Coquerel), was developed for the long-term storage of strains used in research projects and for colonies maintained as back-up to production strains that are mass-reared for sterile insect release programs. This protocol, when combined with a previous procedure that was designed to render screwworm embryos permeable to water loss and the influx of cryoprotectants, yields rates of ~53% hatching, 22% pupation, and 75% adult emergence. These yields are all lower than control levels, but by the next generation the progeny of the cryopreserved flies are near or equal to control …
Eicosanoids Act In Nodulation Reactions To Bacterial Infections In Newly Emerged Adult Honey Bees, Apis Mellifera, But Not In Older Foragers, Jon C. Bedick, Hasan Tunaz, A. R. Nor Aliza, Sean Putnam, Marion D. Ellis, David W. Stanley
Eicosanoids Act In Nodulation Reactions To Bacterial Infections In Newly Emerged Adult Honey Bees, Apis Mellifera, But Not In Older Foragers, Jon C. Bedick, Hasan Tunaz, A. R. Nor Aliza, Sean Putnam, Marion D. Ellis, David W. Stanley
Department of Entomology: Faculty Publications
Nodulation is the first, and qualitatively predominant, cellular defense reaction to bacterial infections in insects. We tested the hypothesis that eicosanoids also mediate nodulation reactions to bacterial challenge in adults of a social insect, the honey bee, Apis mellifera. Treating newly-emerged experimental bees with the eicosanoid biosynthesis inhibitor, dexamethasone, impaired nodulation reactions to bacterial infections, and the influence of dexamethasone was reversed by treating infected insects with arachidonic acid, an eicosanoid precursor. Several other eicosanoid biosynthesis inhibitors, including the cyclooxygenase inhibitor, indomethacin, and the dual cyclooxygenase/lipoxygenase inhibitor, phenidone, also impaired the ability of experimental honeybees to form nodules in …
Oxidative Responses Of Resistant And Susceptible Cereal Leaves To Symptomatic And Nonsymptomatic Cereal Aphid (Hemiptera: Aphididae) Feeding, Xinzhi Ni, Sharron S. Quisenberry, Tiffany Heng-Moss, John P. Markwell, Gautam Sarath, Robert Klucas, Frederick P. Baxendale
Oxidative Responses Of Resistant And Susceptible Cereal Leaves To Symptomatic And Nonsymptomatic Cereal Aphid (Hemiptera: Aphididae) Feeding, Xinzhi Ni, Sharron S. Quisenberry, Tiffany Heng-Moss, John P. Markwell, Gautam Sarath, Robert Klucas, Frederick P. Baxendale
Department of Entomology: Faculty Publications
The impact of the leaf-chlorosis-eliciting Russian wheat aphid, Diuraphis noxia (Mordvilko), and the nonchlorosis-eliciting bird cherry-oat aphid, Rhopalosiphum padi (L.), feeding on D. noxia-susceptible and -resistant cereals was examined during the period (i.e., 3, 6, and 9 d after aphid infestation) that leaf chlorosis developed. After aphid number, leaf rolling and chlorosis ratings, and fresh leaf weight were recorded on each sampling date, total protein content, peroxidase, catalase, and polyphenol oxidase activities of each plant sample were determined spectrophotometrically. Although R. padi and D. noxia feeding caused significant increase of total protein content in comparison with the control cereal …
Effects Of Stable Flies (Diptera: Muscidae) On Weight Gains Of Grazing Yearling Cattle, J.B. Campbell, S.R. Skoda, Dennis Berkebile, D. J. Boxler, G.D. Thomas, D. C. Adams, R. Davis
Effects Of Stable Flies (Diptera: Muscidae) On Weight Gains Of Grazing Yearling Cattle, J.B. Campbell, S.R. Skoda, Dennis Berkebile, D. J. Boxler, G.D. Thomas, D. C. Adams, R. Davis
Department of Entomology: Faculty Publications
Differences in weight gains caused by stable flies, Stomoxys calcitrans (L.), on grazing yearling steer/calves averaged 0.2 kg per steer in a 3-yr study on canyon range pastures in West Central Nebraska. Stable fly numbers averaged 0.85 per front leg on treated calves and 3.64 per front leg on control calves. In 2 of the 3 yr after the grazing trials were completed, the calves were placed in a feedlot and fed a finishing ration. Compensatory gain did not occur in the feedlot after the stable fly stress was removed.
Pcr–Rflp Of The Mitochondrial Cytochrome Oxidase (Subunit I) Gene Provides Diagnostic Markers For Selected Diabrotica Species (Coleoptera: Chrysomelidae), Thomas L. Clark, Lance J. Meinke, John E. Foster
Pcr–Rflp Of The Mitochondrial Cytochrome Oxidase (Subunit I) Gene Provides Diagnostic Markers For Selected Diabrotica Species (Coleoptera: Chrysomelidae), Thomas L. Clark, Lance J. Meinke, John E. Foster
Department of Entomology: Faculty Publications
Adult and larval identification of Diabrotica can be difficult. Some adult identifications require considerable taxonomic experience while larvae of many Diabrotica species are morphologically indistinguishable. This study was conducted to determine whether 12 pest and non-pest Diabrotica species could be separated using polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). A 1308 bp portion of the mitochondrial cytochrome oxidase subunit I gene (COI) was amplified using PCR and digested using several restriction endonucleases. Double digests of COI amplicons with AluI and MspI resolved on polyacrylamide gels revealed several diagnostic inter- and intraspecific polymorphisms. A key to the 12 species …
Molecular Phylogeny Of Diabrotica Beetles (Coleoptera: Chrysomelidae) Inferred From Analysis Of Combined Mitochondrial And Nuclear Dna Sequences, Thomas L. Clark, Lance J. Meinke, John E. Foster
Molecular Phylogeny Of Diabrotica Beetles (Coleoptera: Chrysomelidae) Inferred From Analysis Of Combined Mitochondrial And Nuclear Dna Sequences, Thomas L. Clark, Lance J. Meinke, John E. Foster
Department of Entomology: Faculty Publications
The phylogenetic relationships of thirteen Diabrotica (representing virgifera and fucata species groups) and two outgroup Acalymma beetle species (Coleoptera: Chrysomelidae) were inferred from the phylogenetic analysis of a combined data set of 1323 bp of mitochondrial DNA (mtDNA) cytochrome oxidase subunit 1 (COI) and the entire second internal transcribed spacer region (ITS-2) of nuclear ribosomal DNA of 362 characters. Species investigated were D. adelpha, D. balteata, D. barberi, D. cristata, D. lemniscata, D. longicornis, D. porracea, D. speciosa, D. undecimpunctata howardi, D. u. undecimpunctata, D. virgifera virgifera, D. v. zeae, D. viridula, and outgroup A. blandulum and A. vittatum. Maximum …
Arthropod Populations And Rice Yields In Direct-Seeded And Transplanted Lowland Rice In West Africa, I. O. Oyediran, E. A. Heinrichs
Arthropod Populations And Rice Yields In Direct-Seeded And Transplanted Lowland Rice In West Africa, I. O. Oyediran, E. A. Heinrichs
Department of Entomology: Faculty Publications
Two methods for planting rice in irrigated lowland were evaluated during the wet seasons of 1994 and 1995 to determine their effect on rice arthropod numbers, insect-caused rice plant damage, and rice grain yield. The six treatments tested were: hand transplanting of seedlings at spacings of 14 cm × 14 cm, 20 cm × 20 cm, and 30 cm × 30 cm; and direct-seeding of rice at 60 kg seeds ha–1, 90 kg seeds ha–1, and 120 kg seeds ha–1. The most abundant arthropods in the study were the diopsid flies, Diopsis longicornis Maquart …
Development Of European Corn Borer Larvae On Event 176 Bt Corn: Influence On Survival And Fitness, Blair D. Siegfried, Amelia C. Zoerb, Terrence A. Spencer
Development Of European Corn Borer Larvae On Event 176 Bt Corn: Influence On Survival And Fitness, Blair D. Siegfried, Amelia C. Zoerb, Terrence A. Spencer
Department of Entomology: Faculty Publications
European corn borer larvae, Ostrinia nubilalis (Hübner) (Lepidoptera: Crambidae) that have completed development on Event 176 Bt corn hybrids have survived exposure to sublethal doses of the Cry1Ab Bt toxin or are exploiting plant tissues that do not express the toxin. To evaluate the impact of such exposure, diapausing larvae were collected from Event 176 and conventional hybrids and compared for rates of pupation, parasitism, fitness (pupal weight, longevity, and fecundity) and susceptibility to the Cry1Ab toxin. Larvae completing development on Event 176 corn exhibited approximately 10% higher survival rates and correspondingly lower parasitism rates than larvae completing development on …
Influence Of Western Corn Rootworm (Coleoptera: Chrysomelidae) Larval Injury On Yield Of Different Types Of Maize, Mario A. Urías-López, Lance J. Meinke
Influence Of Western Corn Rootworm (Coleoptera: Chrysomelidae) Larval Injury On Yield Of Different Types Of Maize, Mario A. Urías-López, Lance J. Meinke
Department of Entomology: Faculty Publications
Two field experiments were conducted in 1995-1996 to determine if there are common yield responses among maize hybrids to larval western corn rootworm, Diabrotica virgifera virgifera LeConte injury. Three yellow dent hybrids, five white food grade dent hybrids, and a popcorn hybrid were included in the study. The minimum level of rootworm injury as measured by root damage ratings (3.2-4.2) that significantly reduced yield was similar across the hybrids included in the study. However, the pattern of yield response to different rootworm injury levels varied among hybrids. This suggests that maize hybrids may inherently differ in their ability to tolerate …
Effects Of Decreasing Thermophotoperiod On The Eastern Subterranean Termite (Isoptera: Rhinotermitidae), Brian J. Cabrera, Shripat T. Kamble
Effects Of Decreasing Thermophotoperiod On The Eastern Subterranean Termite (Isoptera: Rhinotermitidae), Brian J. Cabrera, Shripat T. Kamble
Department of Entomology: Faculty Publications
Eastern subterranean termite, Reticulitermes flavipes (Kollar), workers were exposed to decreasing temperatures and a shift in photoperiod to simulate conditions that are encountered during the fall in eastern Nebraska. Mean water and fat content in termites exposed to a decreasing thermophotoperiod did not differ significantly from controls or laboratory colony termites. Survival was higher for termites subjected to a decreasing thermophotoperiod than for controls. This could be attributed to acclimation to low temperatures or a delayed mortality due to lowered metabolic activity at low temperature. Previously reported data on soil temperatures taken in Lincoln, NE, at a depth of 91.4 …
Decapitation Impacting Effect Of Topically Applied Chlorpyrifos On Acetylcholinesterase And General Esterases In Susceptible And Resistant German Cockroaches (Dictyoptera: Blattellidae), No-Joong Park, Shripat T. Kamble
Decapitation Impacting Effect Of Topically Applied Chlorpyrifos On Acetylcholinesterase And General Esterases In Susceptible And Resistant German Cockroaches (Dictyoptera: Blattellidae), No-Joong Park, Shripat T. Kamble
Department of Entomology: Faculty Publications
The effect of topically applied chlorpyrifos on acetylcholinesterase and other esterases in heads and decapitated bodies of CSMA and Crawford German cockroaches was examined with spectrophotometric enzyme assay and native polyacrylamide gel electrophoresis. The toxicity of chlorpyrifos was greatly reduced in decapitated CSMA male cockroaches with LD50 value 17.1-fold higher than that of normal CSMA cockroaches. Acetylcholinesterase activity from heads was significantly higher in the Crawford compared with the CSMA strain and did not change until 24 h after chlorpyrifos in vivo treatment in both strains. The p-nitrophenyl butyrate (NPB) esterase activities from both heads and decapitated bodies of …
Cross-Resistance And Resistance Longevity As Induced By Bean Leaf Beetle, Cerotoma Trifurcata And Soybean Looper, Pseudoplusia Includens Herbivory On Soybean, P. Srinivas, Stephen D. Danielson, C. Michael Smith, John E. Foster
Cross-Resistance And Resistance Longevity As Induced By Bean Leaf Beetle, Cerotoma Trifurcata And Soybean Looper, Pseudoplusia Includens Herbivory On Soybean, P. Srinivas, Stephen D. Danielson, C. Michael Smith, John E. Foster
Department of Entomology: Faculty Publications
Cross-resistance, and longevity of resistance, induced by the bean leaf beetle, Cerotoma trifurcata, was studied IN the soybean PI 227687 that exhibited induced response in earlier studies. Bean leaf beetle adults and soybean looper, Pseudoplusia includens, larvae were used to induce resistance and to determine beetle feeding preference. Beetles were collected from soybean fields 2 to 5 days prior to the feeding preference test. The level of cross-resistance induced by soybean looper herbivory to subsequent bean leaf beetle feeding was higher when compared to cross-resistance induced by bean leaf beetle herbivory against subsequent feeding by soybean looper. Further, …
Occurrence Of Wolbachia In Selected Diabroticite (Coleoptera: Chrysomelidae) Beetles, Thomas L. Clark, Lance J. Meinke, Steven R. Skoda, John E. Foster
Occurrence Of Wolbachia In Selected Diabroticite (Coleoptera: Chrysomelidae) Beetles, Thomas L. Clark, Lance J. Meinke, Steven R. Skoda, John E. Foster
Department of Entomology: Faculty Publications
Wolbachia are a rickettsial type bacteria that have been implicated as a cause of reproductive disruption and alteration in many insect species. Polymerase chain reaction assays of the 16S rRNA gene were conducted to reveal the prevalence of Wolbachia in 14 Diabroticite species, 12 Diabrotica, and two Acalymma. Assays revealed the presence of Wolbachia infection in three Diabrotica species; D. virgifera virgifera LeConte (all 40 individuals), D. cristata (Harris) (three of 25 individuals), D. lemniscata LeConte (all 20 individuals), and the two Acalymma species, A. blandulum (LeConte) (all 20 individuals), A. vittatum (F.) (one of 20 individuals). The …
Expression And Induction Of Three Family 4 Cytochrome P450 (Cyp4)* Genes Identified From Insecticide-Resistant And Susceptible Western Corn Rootworms, Diabrotica Virgifera Virgifera, M. E. Scharf, S. Parimi, Lance J. Meinke, L. D. Chandler, Blair D. Siegfried
Expression And Induction Of Three Family 4 Cytochrome P450 (Cyp4)* Genes Identified From Insecticide-Resistant And Susceptible Western Corn Rootworms, Diabrotica Virgifera Virgifera, M. E. Scharf, S. Parimi, Lance J. Meinke, L. D. Chandler, Blair D. Siegfried
Department of Entomology: Faculty Publications
We have previously determined that cytochrome P450-based oxidation is involved in resistance to the insecticides methyl parathion and carbaryl in geographically distinct Nebraska western corn rootworm populations. Three new family 4 cytochrome P450 (CYP4) gene fragments (CYP4AJ1, CYP4G18 and CYP4AK1) were cloned and sequenced from insecticide-resistant and -susceptible western corn rootworms. Insecticide bioassays indicated the resistant population employed in this study was significantly resistant to the insecticides methyl parathion and carbaryl. CYP4AJ1 and CYP4G18 were cloned from both genomic PCR and RT-PCR products, although only CYP4AJ1 contains an intronic region. Alignments of inferred amino acid sequences with other homologous insect …
Effect Of The Chemical Inducer Actigard™ In Inducing Resistance To Bean Leaf Beetle, Cerotoma Trifurcata (Forster) (Coleoptera: Chrysomelidae), Feeding In Soybean, Parimi Srinivas, Stephen D. Danielson
Effect Of The Chemical Inducer Actigard™ In Inducing Resistance To Bean Leaf Beetle, Cerotoma Trifurcata (Forster) (Coleoptera: Chrysomelidae), Feeding In Soybean, Parimi Srinivas, Stephen D. Danielson
Department of Entomology: Faculty Publications
Induced resistance in soybean was investigated in the greenhouse using different concentrations of the chemical inducer Actigard™ to determine the influence on feeding preference of bean leaf beetle adults. Treatments of 0 (control), 15, 25, 40, 60, and 80 ppm Actigard™, and artificial defoliation followed by 25 ppm Actigard™ were applied to V1 and V6 stages of soybean plants. Dual-choice feeding preference tests with the bean leaf beetle were used to assess induced resistance. The adult beetles were collected from soybean fields in east central Nebraska 2 to 5 days prior to the feeding preference tests. Pair-wise comparisons of leaflets …
Induction Of Resistance In Field Grown Soybean By The Bean Leaf Beetle, Cerotoma Trifurcata (Forster) (Coleoptera: Chrysomelidae), Parimi Srinivas, Stephen D. Danielson
Induction Of Resistance In Field Grown Soybean By The Bean Leaf Beetle, Cerotoma Trifurcata (Forster) (Coleoptera: Chrysomelidae), Parimi Srinivas, Stephen D. Danielson
Department of Entomology: Faculty Publications
A study was conducted during the summer of 1998 with soybean cultivar Colfax, germplasm line HC95-24MB and susceptible cultivar Williams 82 to investigate induced resistance in soybean. Bean leaf beetle adults were used to induce resistance in field and also in the dual-choice feeding preference tests that were done in the laboratory to assess induction. Pair-wise comparisons of leaflets from induced and control plants demonstrated that induced resistance was present. Preference index (PI) values were similar in the three soybean entries and were not significantly different. Further investigation is necessary to fully understand induced resistance under field conditions in soybean-insect …
Dispersal Of Adult European Corn Borer (Lepidoptera: Crambidae) Within And Proximal To Irrigated And Non–Irrigated Corn, Thomas E. Hunt, Leon G. Higley, John F. Witkowski, Linda J. Young, Richard L. Hellmich
Dispersal Of Adult European Corn Borer (Lepidoptera: Crambidae) Within And Proximal To Irrigated And Non–Irrigated Corn, Thomas E. Hunt, Leon G. Higley, John F. Witkowski, Linda J. Young, Richard L. Hellmich
Department of Entomology: Faculty Publications
The European corn borer, Ostrinia nubilalis (Hübner), causes economic damage to corn, Zea mays L., throughout the Corn Belt. Because this insect has become the primary target of Bacillus thuringiensis Berliner (Bt) transgenic corn, current efforts addressing the management of O. nubilalis resistance to Bt corn require information on adult European corn borer dispersal and factors affecting its dispersal. In 1998 we conducted mark-release-recapture, release-recapture, and caged-mating studies to directly measure and compare local dispersal patterns of O. nubilalis adults within and proximal to irrigated and non-irrigated cornfields. Releases of marked adults were made corresponding to the first and second …