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Full-Text Articles in Agriculture
Geographic Distribution Of Bacillus Thuringiensis Cry1f Toxin Resistance In Western Bean Cutworm (Lepidoptera: Noctuidae) Populations In The United States, Brad S. Coates, Craig A. Abel, Katharine A. Swoboda-Bhattarai, Debra E. Palmquist, Débora Goulart Montezano, Sarah N. Zukoff, Yangzhou Wang, Jeffery D. Bradshaw, Christina D. Difonzo, Elson Shields, Kelley J. Tilmon, Thomas Hunt, Julie A. Peterson
Geographic Distribution Of Bacillus Thuringiensis Cry1f Toxin Resistance In Western Bean Cutworm (Lepidoptera: Noctuidae) Populations In The United States, Brad S. Coates, Craig A. Abel, Katharine A. Swoboda-Bhattarai, Debra E. Palmquist, Débora Goulart Montezano, Sarah N. Zukoff, Yangzhou Wang, Jeffery D. Bradshaw, Christina D. Difonzo, Elson Shields, Kelley J. Tilmon, Thomas Hunt, Julie A. Peterson
West Central Research and Extension Center, North Platte
The western bean cutworm (WBC), Striacosta albicosta (Lepidoptera: Noctuidae), can be a severe pest of transgenic corn in the western Plains and Great Lakes regions of North America, including on hybrids expressing the Bacillus thuringiensis (Bt) Cry1F toxin. The level and geographic distribution of Cry1F resistance are not completely known. Neonate S. albicosta from 10 locations between Nebraska and New York state were subjected to dose–response trypsin-activated native Cry1F toxin overlay bioassays. In 2017, the mean estimated lethal concentration causing 50% larval mortality (LC50) ranged from 15.1 to 18.4 μg Cry1F cm−2, and were not significantly different among locations. In …
Characterization Of Resistance To The Cry1f Toxin From Bacillus Thuringiensis In Resistant Fall Armyworm, Spodoptera Frugiperda (J. E. Smith) (Lepidoptera: Noctuidae) From Puerto Rico, Ana Maria Velez
Department of Entomology: Dissertations, Theses, and Student Research
Transgenic corn expressing Cry1F protein from Bacillus thuringiensis Berliner has been registered for Spodoptera frugiperda control since 2003. Unexpected damage to Cry1F corn 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 from Puerto Rico which displayed >387-fold resistance to 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 strain suggest that a single locus is responsible …
Feeding Behavior Of Nephotettix Virescens (Homoptera: Cicadellidae) On Rice Varieties With Different Levels Of Resistance, H. R. Rapusas, E. A. Heinrichs
Feeding Behavior Of Nephotettix Virescens (Homoptera: Cicadellidae) On Rice Varieties With Different Levels Of Resistance, H. R. Rapusas, E. A. Heinrichs
Department of Entomology: Faculty Publications
The feeding behavior of Nephotettix virescens (Distant) on rice varieties with different levels of resistance was studied using an AC electronic monitor for insect feeding (EMIF) system. Varieties used were TN1 (susceptible), IR36 (moderately resistant), and ASD7, IR60, and IR64 (resistant). Six typical waveforms were recorded, and each type corresponded to a certain activity of the insect during the feeding process as indicated by histological sections of the leaf observed. Significantly more phloem feeding was observed on the susceptible plants than on the moderately resistant and resistant plants. Fifty percent of the total test period was spent feeding on the …
Plant Age Effect On The Level Of Resistance Of Rice “Ir36” To The Green Leafhopper, Nephotettix Virescens (Distant) And Rice Tungro Virus, H. R. Rapusas, E. A. Heinrichs
Plant Age Effect On The Level Of Resistance Of Rice “Ir36” To The Green Leafhopper, Nephotettix Virescens (Distant) And Rice Tungro Virus, H. R. Rapusas, E. A. Heinrichs
Department of Entomology: Faculty Publications
Plant age of a moderately resistant rice cultivar, “IR36,” had a distinct effect on the level of Nephotettix virescens (Distant) resistance. Plants at 10 d after sowing (DAS) were preferred over those at 20, 40, or 60 DAS. N. virescens survival, growth index, and adult weight were higher on plants 20 DAS than on plants 40, 60, or 80 DAS. Although the total amount of honeydew excreted was similar for “IR36” plants of all ages, the reaction of honeydew on filter paper treated with bromocresol green indicated that feeding in the nutrient-rich phloem was highest on the younger plants. Tungro …
Appraisal For Combined Pea Aphid And Spotted Alfalfa Aphid Resistance In Alfalfa, W. L. Howe, W. R. Kehr, C. O. Calkins
Appraisal For Combined Pea Aphid And Spotted Alfalfa Aphid Resistance In Alfalfa, W. L. Howe, W. R. Kehr, C. O. Calkins
Nebraska Agricultural Experiment Station: Historical Research Bulletins
Sources of combined resistance to spotted alfalfa and pea aphids were found in Ranger alfalfa and its parental strains, foreign plant introductions, clones and their progenies. Ranger alfalfa appeared to be a good source for selection of plants with resistance to both aphids.
Studies Of The Mechanisms And Sources Of Spotted Alfalfa Aphid Resistance In Ranger Alfalfa, W. L. Howe, W. R. Kehr, M. E. Mcknight, G. R. Manglitz
Studies Of The Mechanisms And Sources Of Spotted Alfalfa Aphid Resistance In Ranger Alfalfa, W. L. Howe, W. R. Kehr, M. E. Mcknight, G. R. Manglitz
Nebraska Agricultural Experiment Station: Historical Research Bulletins
Mechanisms and sources of spotted alfalfa aphid resistance in Ranger alfalfa and its five parental strains were investigated during 1957-1960.