Anatomy of a pest control failure: introgression of cytochrome P450 337B3 alleles from invasive old-world bollworm into native corn earworm (Lepidoptera: Noctuidae).

The establishment of invasive species populations can threaten the ecological balance in naïve habitats and impact agricultural production practices. Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) (old-world bollworm, OWBW) and Helicoverpa zea (corn earworm, CEW) were geographically separated prior to the 2013 report of OWBW invasion into South America. Introgression of OWBW-specific cytochrome P450 337B3 (CYP337B3) gene into CEW was repeatedly detected across South America and the Caribbean.

Wisconsin diversity panel phenotypes: spoken descriptions of plants and supporting data.

Objectives: Phenotyping plants in a field environment can involve a variety of methods including the use of automated instruments and labor-intensive manual measurement and scoring. Researchers also collect language-based phenotypic descriptions and use controlled vocabularies and structures such as ontologies to enable computation on descriptive phenotype data, including methods to determine phenotypic similarities. In this study, spoken descriptions of plants were collected and observers were instructed to use their own vocabulary to describe plant features that were present and visible.

Extended Sentinel Monitoring of Resistance to Cry and Vip3Aa Toxins in Bt Sweet Corn: Assessing Changes in Phenotypic and Allele Frequencies of Resistance.

Transgenic corn and cotton that produce Cry and Vip3Aa toxins derived from (Bt) are widely planted in the United States to control lepidopteran pests. The sustainability of these Bt crops is threatened because the corn earworm/bollworm, (Boddie), is evolving a resistance to these toxins. Using Bt sweet corn as a sentinel plant to monitor the evolution of resistance, collaborators established 146 trials in twenty-five states and five Canadian provinces during 2020-2022.

Geographic Distribution of Bacillus thuringiensis Cry1F Toxin Resistance in Western Bean Cutworm (Lepidoptera: Noctuidae) Populations in the United States.

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.

Temporal Variation in Genetic Composition of Migratory in Peripheral Populations.

Migrant populations of (Boddie) captured during 2002, 2005, 2016, and 2018 from Landisville and Rock Springs in Pennsylvania, USA were genotyped using 85 single nucleotide polymorphism (SNP) markers. Samples (n = 702) genotyped were divided into 16 putative populations based on collection time and site. Fixation indices (-statistics), analysis of molecular variance, and discriminant analysis of principal components were used to examine within and among population genetic variation.

Differentiation of European Corn Borer (Lepidoptera: Crambidae) and American Lotus Borer (Lepidoptera: Crambidae), Ostrinia penitalis, from North American Field Collections.

The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is a perennial insect pest of cultivated maize that was inadvertently introduced into North America in the early 1900s, but population densities have decreased since the widespread adoption of transgenic hybrids that express Bacillus thuringiensis (Bt) toxins. The native American lotus borer, Ostrinia penitalis (Lepidoptera: Crambidae), is among the most ancestral species described in the genus Ostrinia, and has a geographic range that coincides with that of O. nubilalis across major maize growing regions of North America.

Estimation of long terminal repeat element content in the Helicoverpa zea genome from high-throughput sequencing of bacterial artificial chromosome pools.

The lepidopteran pest insect Helicoverpa zea feeds on cultivated corn and cotton across the Americas where control remains challenging owing to the evolution of resistance to chemical and transgenic insecticidal toxins, yet genomic resources remain scarce for this species. A bacterial artificial chromosome (BAC) library having a mean genomic insert size of 145 ± 20 kbp was created from a laboratory strain of H. zea, which provides ∼12.

The mitochondrial genome of the western bean cutworm, (Lepidoptera: Noctuidae).

The complete 15,553 bp mitochondrial genome of the western bean cutworm, , (Lepidoptera: Noctuidae) was assembled from paired end Illumina HiSeq2500 read data. Annotation showed 13 predicted protein coding genes (PCGs), 22 tRNAs and 2 rRNAs have an order and orientation typical of insect mitochondrial genomes, and the derived rearrangement of tRNA-Met, -Ile and -Gln upstream of 2 as in other Lepidoptera. A 79.

Peripheral genetic structure of Helicoverpa zea indicates asymmetrical panmixia.

Seasonal climatic shifts create peripheral habitats that alternate between habitable and uninhabitable for migratory species. Such dynamic peripheral habitats are potential sites where migratory species could evolve high genetic diversity resulting from convergence of immigrants from multiple regionally distant areas. Migrant populations of Helicoverpa zea (Boddie) captured during two different seasons were assessed for genetic structure using microsatellite markers and for host plant type using stable carbon isotope analysis.

Aflatoxin and Fumonisin in Corn (Zea mays) Infected by Common Smut Ustilago maydis.

Corn infected with Ustilago maydis (common smut) produces galls that are valued as a delicacy in some cultures. During a 4-year period, aflatoxin levels in asymptomatic kernels of smutted ears were, on average, 45-fold higher than in kernels harvested from smut-free control ears and 99-fold higher than in smut galls. Aflatoxin levels in smut galls were lower than in kernels of smut-free control corn in all years combined.

The mitochondrial genome of the American lotus borer, Ostrinia penitalis (Lepidoptera: Crambidae).

The American lotus borer, Ostrinia penitalis, is the most ancestral among more than 20 species described in the genus Ostrinia, and the near complete mitochondrial genome sequence described here is important for phylogenetic comparisons. The 12,612 bp contiguous fragment contains 13 protein coding genes, 20 tRNAs and a partial rRNA gene complement. Compared to two previously sequenced Ostrinia mitochondrial genomes, gene order and orientation remains identical.

Effect of maize lines on larval fitness costs of Cry1F resistance in the European corn borer (Lepidoptera: Crambidae).

Crops producing insecticidal toxins from the bacterium Bacillus thuringiensis (Bt) are widely planted and enable management of key insect pests while reducing the use of conventional insecticides. However, the evolution of Bt resistance could diminish these benefits. Fitness costs of Bt resistance occur in the absence of Bt toxin when individuals with resistance alleles show a reduction in fitness relative to susceptible individuals, and they can delay the evolution of resistance.

Frequency of hybridization between Ostrinia nubilalis E-and Z-pheromone races in regions of sympatry within the United States.

Female European corn borer, Ostrinia nubilalis, produce and males respond to sex pheromone blends with either E- or Z-Δ11-tetradecenyl acetate as the major component. E- and Z-race populations are sympatric in the Eastern United States, Southeastern Canada, and the Mediterranean region of Europe. The E- and Z-pheromone races of O.

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.

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.

Characterization and transcriptional analyses of cDNAs encoding three trypsin- and chymotrypsin-like proteinases in Cry1Ab-susceptible and Cry1Ab-resistant strains of sugarcane borer, Diatraea saccharalis.

Diatraea saccharalis is a major corn borer pest. Midgut serine proteinases are essential for insect growth and development. Alteration of midgut proteinases is responsible for Bt resistance development in some species.

Effects of foliar boron application on seed composition, cell wall boron, and seed δ(15)N and δ(13)C isotopes in water-stressed soybean plants.

Limited information is available on the effects of foliar boron (B) application on soybean seed composition. The objective of this research was to investigate the effects of foliar B on seed composition (protein, oil, fatty acids, and sugars). Our hypothesis was that since B is involved in nitrogen and carbon metabolism, it may impact seed composition.

Implications of Bt traits on mycotoxin contamination in maize: Overview and recent experimental results in southern United States.

Mycotoxin contamination levels in maize kernels are controlled by a complex set of factors including insect pressure, fungal inoculum potential, and environmental conditions that are difficult to predict. Methods are becoming available to control mycotoxin-producing fungi in preharvest crops, including Bt expression, biocontrol, and host plant resistance. Initial reports in the United States and other countries have associated Bt expression with reduced fumonisin, deoxynivalenol, and zearalenone contamination and, to a lesser extent, reduced aflatoxin contamination in harvested maize kernels.

Distribution of genes and repetitive elements in the Diabrotica virgifera virgifera genome estimated using BAC sequencing.

Feeding damage caused by the western corn rootworm, Diabrotica virgifera virgifera, is destructive to corn plants in North America and Europe where control remains challenging due to evolution of resistance to chemical and transgenic toxins. A BAC library, DvvBAC1, containing 109,486 clones with 104 ± 34.5 kb inserts was created, which has an ~4.

Cloning eleven midgut trypsin cDNAs and evaluating the interaction of proteinase inhibitors with Cry1Ac against the tobacco budworm, Heliothis virescens (F.) (Lepidoptera: Noctuidae).

Midgut trypsins are associated with Bt protoxin activation and toxin degradation. Proteinase inhibitors have potential insecticidal toxicity against a wide range of insect species. This study was conducted to evaluate the interaction of proteinase inhibitors with Bt toxin and to examine midgut trypsin gene profile of Heliothis virescens.

Mobilizing the genome of Lepidoptera through novel sequence gains and end creation by non-autonomous Lep1 Helitrons.

Transposable elements (TEs) can affect the structure of genomes through their acquisition and transposition of novel DNA sequences. The 134-bp repetitive elements, Lep1, are conserved non-autonomous Helitrons in lepidopteran genomes that have characteristic 5'-CT and 3'-CTAY nucleotide termini, a 3'-terminal hairpin structure, a 5'- and 3'-subterminal inverted repeat (SIR), and integrations that occur between AT or TT nucleotides. Lep1 Helitrons have acquired and propagated sequences downstream of their 3'-CTAY termini that are 57-344-bp in length and have termini composed of a 3'-CTRR preceded by a 3'-hairpin structure and a region complementary to the 5'-SIR (3'-SIRb).

Down regulation of a gene for cadherin, but not alkaline phosphatase, associated with Cry1Ab resistance in the sugarcane borer Diatraea saccharalis.

The sugarcane borer, Diatraea saccharalis, is a major target pest of transgenic corn expressing Bacillus thuringiensis (Bt) proteins (i.e., Cry1Ab) in South America and the mid-southern region of the United States.

A single major QTL controls expression of larval Cry1F resistance trait in Ostrinia nubilalis (Lepidoptera: Crambidae) and is independent of midgut receptor genes.

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.

Molecular characterization and RNA interference of three midgut aminopeptidase N isozymes from Bacillus thuringiensis-susceptible and -resistant strains of sugarcane borer, Diatraea saccharalis.

Aminopeptidase N (APN) proteins located at the midgut epithelium of some lepidopteran species have been implicated as receptors for insecticidal proteins from Bacillus thuringiensis. cDNAs of three APN isoforms, DsAPN1, DsAPN2, and DsAPN3, from Cry1Ab-susceptible (Cry1Ab-SS) and -resistant (Cry1Ab-RR) strains of the sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), were identified and sequenced using reverse transcriptase polymerase chain reaction (RT-PCR) and 5' rapid amplification of cDNA end (5' RACE).

Oviposition and development of the tarnished plant bug (Heteroptera: Miridae) on field maize.

Reduced insecticide use in cotton, Gossypium hirsutum L., as a consequence of the Boll Weevil Eradication Program and the broad adoption of Bt cotton, have helped make the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), a consistent pest of cotton each year in the mid-south. Maize, Zea mays L.