scholarly journals Managing the Sugarcane Borer,Diatraea saccharalis, and Corn Earworm,Helicoverpa zea, using Bt Corn and Insecticide Treatments

2013 ◽  
Vol 13 (109) ◽  
pp. 1-10 ◽  
Author(s):  
Juliano R. Farias ◽  
Ervandil C. Costa ◽  
Jerson V. C. Guedes ◽  
Alessandro P. Arbage ◽  
Armando B. Neto ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Corn Earworm ◽  
Bt Corn ◽  
Sugarcane Borer ◽  
Diatraea Saccharalis

scholarly journals ACTION SPECTRUM OF Baculovirus spodoptera ON LEPIDOPTERA PESTS

2017 ◽  
Vol 16 (1) ◽  
pp. 52
Author(s):  
CAMILA DA SILVA FERNANDES SOUZA ◽  
FERNANDO HERCOS VALICENTE ◽  
MARCOS ANTÔNIO MATIELLO FADINI ◽  
RICARDO ANTÔNIO POLANCZYK
Keyword(s):  
Spodoptera Frugiperda ◽  
Sugar Cane ◽  
Helicoverpa Zea ◽  
First Generation ◽  
Action Spectrum ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Corn Borer ◽  
Egg Masses ◽  
Diatraea Saccharalis

ABSTRACT - This work evaluated the spectrum of action of Baculovirus spodoptera (SfMNVP) - 6NR on the fall armyworm Spodoptera frugiperda, corn earworm Helicoverpa zea and the sugar cane borer Diatraea saccharalis, species of economic importance in maize. For the bioassays, corn leaves immersed in a baculovirus suspension were used for baculovirus inoculation in fall armyworm and earworm and pieces of sugar cane for the corn borer. The foods were immersed in viral solutions of different baculovirus concentrations determined in a Neubauer chamber. The control only distilled water was used instead of the baculovirus suspension. The larvae fed for 48 hours and were then transferred to an artificial diet, without the baculovirus. After evaluating mortality, the development of the offspring (F1) was accompanied, evaluating the parameters: mortality, pupation and the number of egg masses in the first generation. The baculovirus was specific to fall armyworm and innocuous to earworm and the corn borer in the first generation. In the second generation, baculovirus was innocuous for all three species. The percentage of pupation showed an inverse relation with mortality for the three species in two generations. The number of egg masses in F1 was lower in S. frugiperda, did not change for D. saccharalis and higher in H. zea.Keywords: Helicoverpa zea, Spodoptera frugiperda, Diatraea saccharalis, entomopathogenie virus.ESPECTRO DE AÇÃO DE Baculovirus spodoptera A LEPIDÓPTEROS PRAGARESUMO - Neste trabalho foi avaliado o espectro de ação do Baculovirus spodoptera (SfMNVP) - 6NR à lagarta-do-cartucho Spodoptera frugiperda, à lagarta-da-espiga Helicoverpa zea e à broca-da-milho Diatraea saccharalis, espécies de importância econômica na cultura do milho. Para a realização dos bioensaios foram utilizadas folhas de milho imersas em suspensão com o baculovírus em concentrações determinadas em câmara de Neubauer, para lagarta-do-cartucho e para lagarta-da-espiga. Para broca-do-milho o substrato utilizado foi colmo de cana-de-açúcar. Na testemunha foi utilizada somente água destilada ao invés da suspensão com o baculovírus. As lagartas se alimentaram por 48 horas, após este período, foram transferidas para dieta artificial sem o bacilovírus. Após a avaliação da mortalidade,odesenvolvimento da prole (F1) foi acompanhado sendo avaliados os parâmetros: mortalidade, pupação e o número de massas de ovos na primeira geração. O baculovírus foi especifico para lagarta-do-cartucho e inócuo tanto para lagarta-da-espiga quanto para broca-do-milho na primeira geração. Na segunda geração, o baculovírus foi inócuo para as três espécies. A porcentagem de pupação apresentou relação inversa com a mortalidade para as três espécies nas duas gerações. O número de massas de ovos na F1 foi menor em S. frugiperda, não alterado para D. saccharalis e maior em H. zea.Palavras-chave: Helicoverpa zea, Spodoptera frugiperda, Diatraea saccharalis, vírus entomopatogênico.

Influence of Transgenic Corn Expressing Insecticidal Protein of Bacillus thuringiensis Berliner on Natural Populations of Corn Earworm (Lepidoptera: Noctuidae) and Southwestern Corn Borer (Lepidoptera: Crambidae)

2006 ◽  
Vol 41 (3) ◽  
pp. 221-231 ◽  
Author(s):  
Kerry C. Allen ◽  
Henry N. Pitre
Keyword(s):  
Bacillus Thuringiensis ◽  
Helicoverpa Zea ◽  
Larval Growth ◽  
Natural Populations ◽  
Corn Earworm ◽  
Bt Corn ◽  
Transgenic Corn ◽  
Diatraea Grandiosella ◽  
Corn Hybrids ◽  
Corn Borer

A 2-yr study was conducted to measure the influence of transgenic corn, Zea mays L., expressing the CrylAb endotoxin of Bacillus thuringiensis (Berliner) (Bt) by means of Event MON810 on natural populations of Helicoverpa zea (Boddie) and Diatraea grandiosella (Dyar). The studies were conducted at Leland and Morgan City, MS, in 1999 and at Morgan City in 2000. Although total numbers of H. zea larvae were not significantly different on transgenic corn hybrids compared with their near-isogenic parent lines, fewer large larvae were found on the transgenic hybrids. Differences in H. zea larval growth were noticeable when larvae fed on Bt corn vs non-Bt corn. The delay in larval growth for insects within a single generation, which could possibly result in asynchronous mating between insecticide resistant and susceptible insects, was observed for larvae feeding on plants expressing the Bt toxin. Diatraea grandiosella caused limited damage to the transgenic corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with their near-isogenic parent lines. Yields were not significantly greater for the Bt corn hybrids compared with the near-isogenic, non-Bt corn parents; however, there was a trend toward higher yields for Bt hybrids compared with their near-isogenic non-Bt parents.

Reproductive isolation between two populations of Diatraea saccharalis (F.) (Lepidoptera: Crambidae) from different host plant species and regions in Argentina

2016 ◽  
Vol 106 (5) ◽  
pp. 591-597 ◽  
Author(s):  
S.V. Fogliata ◽  
A. Vera ◽  
G. Gastaminza ◽  
M.I. Cuenya ◽  
M.I. Zucchi ◽  
...  
Keyword(s):  
Gene Flow ◽  
Host Plant ◽  
Buenos Aires ◽  
Western Hemisphere ◽  
Bt Corn ◽  
Generalist Species ◽  
Sugarcane Borer ◽  
Diatraea Saccharalis ◽  
Geographic Populations ◽  
Two Populations

AbstractThe sugarcane borer, Diatraea saccharalis (F.), has a widespread distribution throughout the Western Hemisphere and is a pest of many crop plants including sugarcane, corn, sorghum and rice. The use of Bacillus thuringiensis (Bt) corn has been the primary tool for managing this species in corn fields. Sugarcane borer control has been recently threatened by observations of susceptibility and/or resistance to certain varieties of Bt corn and the protein used in many newer varieties. This has led to increased interest in understanding sugarcane borer genetic diversity and gene flow within and among its populations and the consequent exchange of alleles between geographically distant populations. The objective of this study was to examine reproductive compatibility between host-associated geographic populations of D. saccharalis in Argentina and to determine whether this pest represents a complex of host-associated cryptic species rather than a wide ranging generalist species. Intra and inter-population crosses revealed that D. saccharalis populations from the northwestern and Pampas regions presented evidence of prezygotic and postzygotic incompatibility. Such a result is likely to be the product of an interruption of gene flow produced by either geographic or host plant associated isolation, suggesting that Tucumán (northwestern) and Buenos Aires (Pampas) populations of D. saccharalis are a distinct genotype and possibly an incipient species.

scholarly journals Populations of Helicoverpa zea (Boddie) in the Southeastern United States are Commonly Resistant to Cry1Ab, but Still Susceptible to Vip3Aa20 Expressed in MIR 162 Corn

Toxins ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 63 ◽  
Author(s):  
Ying Niu ◽  
Isaac Oyediran ◽  
Wenbo Yu ◽  
Shucong Lin ◽  
Marcelo Dimase ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Corn Earworm ◽  
Current Status ◽  
Bt Corn ◽  
Bt Crops ◽  
Bt Toxin ◽  
Resistance Evolution ◽  
Major Pest ◽  
The Impact ◽  
The U.S

The corn earworm, Helicoverpa zea (Boddie), is a major pest targeted by pyramided Bacillus thuringiensis (Bt) corn and cotton in the U.S. Cry1Ab is one of the first insecticidal toxins used in Bt crops, while Vip3A is a relatively new toxin that has recently been incorporated into Cry corn with event MIR 162 and Cry cotton varieties to generate pyramided Bt traits targeting lepidopteran pests including H. zea. The objectives of this study were to determine the current status and distribution of the Cry1Ab resistance, and evaluate the susceptibility to Vip3Aa20 expressed in MIR 162 corn in H. zea in the southeastern U.S. During 2018 and 2019, 32 H. zea populations were collected from non-Bt corn (19 populations), Cry corn (12), and Cry/Vip3A cotton (1) across major corn areas in seven southeastern states of the U.S. Susceptibility of these populations to Cry1Ab and Vip3Aa20 was determined using diet-overlay bioassays. Compared to a known susceptible insect strain, 80% of the field populations were 13- to >150-fold resistant to Cry1Ab, while their response to Vip3Aa20 ranged from >11-fold more susceptible to 9-fold more tolerant. Mean susceptibility to each Bt toxin was not significantly different between the two groups of the populations collected from non-Bt and Bt crops, as well as between the two groups of the populations collected during 2018 and 2019. The results show that resistance to Cry1Ab in H. zea is widely distributed across the region. However, the Cry1Ab-resistant populations are not cross-resistant to Vip3Aa20, and H. zea in the region is still susceptible to the Vip3Aa20 toxin. Vip3Aa20 concentrations between 5 and 10 µg/cm2 may be used as diagnostic concentrations for susceptibility monitoring in future. Additional studies are necessary to elucidate the impact of the selection with Bt corn on resistance evolution in H. zea to Vip3A cotton in the U.S.

Susceptibility of Corn Earworm (Lepidoptera: Noctuidae) to Cry1A.105 and Cry2Ab2 in North and South Carolina

2019 ◽  
Vol 112 (4) ◽  
pp. 1845-1857 ◽  
Author(s):  
Tom R Bilbo ◽  
Francis P F Reay-Jones ◽  
Dominic D Reisig ◽  
Jeremy K Greene
Keyword(s):  
United States ◽  
South Carolina ◽  
Helicoverpa Zea ◽  
Natural Populations ◽  
The United States ◽  
Corn Earworm ◽  
Pupal Weight ◽  
Bt Corn ◽  
Development Of Resistance ◽  
Bacterium Bacillus

Abstract The corn earworm, Helicoverpa zea (Boddie), is managed in corn and cotton in the United States primarily using transgenic cultivars that produce insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). However, increasing reports of resistance to one or more Bt proteins threaten the continued efficacy of Bt traits. To better understand the development of resistance of H. zea to Bt corn and cotton in the southeastern United States, we monitored for resistance to Cry1A.105 and Cry2Ab2 among 22 field populations of H. zea collected in non-Bt and Bt corn expressing Cry1A.105 + Cry2Ab2 during 2017 and 2018. Colonies were established in the laboratory and progeny were screened in diet-overlay bioassays to purified Cry1A.105 and Cry2Ab2 proteins. Compared with two susceptible laboratory colonies, all 14 field colonies tested with Cry1A.105 were highly resistant, with resistance ratios (RRs) ranging from 13.5 to >4,000. For Cry2Ab2, 19 colonies were tested and RRs ranged from 0.26 to 33.7. Field populations were significantly more susceptible to Cry2Ab2 than Cry1A.105. We documented variability in F0 and F1 pupal weight and developmental rates of natural populations of H. zea, but observed no significant correlation with susceptibility to either Cry1A.105 or Cry2Ab2. Our results expand on the recent reports of H. zea resistance to Cry1A and Cry2A proteins and will aid in the design and deployment of future pyramided crops in the United States.

scholarly journals Genetic Mechanisms Underlying Apimaysin and Maysin Synthesis and Corn Earworm Antibiosis in Maize (Zea mays L.)

Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1997-2006
Author(s):  
E A Lee ◽  
P F Byrne ◽  
M D McMullen ◽  
M E Snook ◽  
B R Wiseman ◽  
...  
Keyword(s):  
Helicoverpa Zea ◽  
Larval Growth ◽  
Corn Earworm ◽  
Phenotypic Variance ◽  
Significant Qtls ◽  
F2 Population ◽  
Genetic Mechanisms ◽  
Trait Locus ◽  
Maize Silks ◽  
Related Compounds

Abstract C-glycosyl flavones in maize silks confer resistance (i.e., antibiosis) to corn earworm (Helicoverpa zea [Boddie]) larvae and are distinguished by their B-ring substitutions, with maysin and apimaysin being the di- and monohydroxy B-ring forms, respectively. Herein, we examine the genetic mechanisms underlying the synthesis of maysin and apimaysin and the corresponding effects on corn earworm larval growth. Using an F2 population, we found a quantitative trait locus (QTL), rem1, which accounted for 55.3% of the phenotypic variance for maysin, and a QTL, pr1, which explained 64.7% of the phenotypic variance for apimaysin. The maysin QTL did not affect apimaysin synthesis, and the apimaysin QTL did not affect maysin synthesis, suggesting that the synthesis of these closely related compounds occurs independently. The two QTLs, rem1 and pr1, were involved in a significant epistatic interaction for total flavones, suggesting that a ceiling exists governing the total possible amount of C-glycosyl flavone. The maysin and apimaysin QTLs were significant QTLs for corn earworm antibiosis, accounting for 14.1% (rem1) and 14.7% (pr1) of the phenotypic variation. An additional QTL, represented by umc85 on the short arm of chromosome 6, affected antibiosis (R2 = 15.2%), but did not affect the synthesis of the C-glycosyl flavones.

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