ChemInform Abstract: New Flavone C-Glycosides from Corn (Zea mays L.) for the Control of the Corn Earworm (Helicoverpa zea)

Resistance to corn earworm (CEW) (Helicoverpa zea Boddie) has been attributed to high concentrations of C-glycosyl flavones and chlorogenic acid in maize (Zea mays L.) silks. The most common C-glycosyl flavones isolated from maize silks are maysin, apimaysin, and methoxymaysin, which are distinguished by their B-ring substitutions. For a better understanding of the genetic mechanisms underlying the synthesis of these compounds, we conducted a quantitative trait locus (QTL) study with two populations: (Tx501 × NC7A)F2 and (Tx501 × Mp708)F2. For chlorogenic acid, maysin, and methoxymaysin concentration, the major QTL for both populations was located on chromosome 4 near umc1963. For apimaysin, the major QTL in both populations was located at the position of the pr1 locus on chromosome 5. The QTL alleles on chromosome 4 that increased the synthesis of methoxymaysin significantly decreased the synthesis of maysin and chlorogenic acid. This decrease in maysin concentration was four-fold greater than the increase in methoxymaysin. Our results indicate that the QTL on chromosome 4, responsible for the increase in methoxymaysin synthesis, alters the dynamics of both the phenylpropanoid and flavonoid pathways.Key words: pr1, flavonoid 3'-hydroxylase, maysin, apimaysin, methoxymaysin.

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INFESTAÇÃO DE MILHO CRIOULO, CONVENCIONAL E TRANSGÊNICO PELA LAGARTA-DO-CARTUCHO E PELA LAGARTA-DA-ESPIGA E PARASITISMO DE OVOS

Revista Brasileira de Milho e Sorgo ◽

10.18512/1980-6477/rbms.v16n3p351-360 ◽

2017 ◽

Vol 16 (3) ◽

pp. 351

Author(s):

CAMILA CORRÊA VARGAS ◽

ROSANA MATOS DE MORAIS ◽

LUIZA RODRIGUES REDAELLI

Keyword(s):

Zea Mays ◽

Spodoptera Frugiperda ◽

Helicoverpa Zea ◽

Genetically Modified ◽

Fall Armyworm ◽

Corn Earworm ◽

Trichogramma Pretiosum ◽

Hybrid Corn ◽

Egg Parasitism ◽

Santa Maria

RESUMO - O objetivo foi avaliar a infestação, o parasitismo de ovos e danos da lagarta-do-cartucho, Spodoptera frugiperda (J. E. Smith), e da lagarta-da-espiga, Helicoverpa zea (Boddie), em cultivares de milho: variedade crioulo (Lombo Baio), híbrido convencional (Semilha S395) e híbrido geneticamente modificado (Bt) (TC1507 Herculex I ®, Cry1F). O experimento foi conduzido em Santa Maria-RS, no período de segunda safra de 2014. O delineamento foi de blocos ao acaso, com três tratamentos e quatro repetições. Foram registrados os danos, o número de lagartas, de posturas e o parasitismo em ovos da lagarta-do-cartucho, dos 9 aos 72 dias após a emergência das plantas (DAE). A infestação da lagarta-da-espiga e o parasitismo de ovos foram registrados dos 67 aos 101 DAE. Os danos causados pela lagarta-do-cartucho foram semelhantes entre milho crioulo e convencional, os quais foram mais elevados do que no milho geneticamente modificado Bt. O número médio de lagartas-do-cartucho foi maior em milho crioulo. A média do número total de lagartas-da-espiga foi semelhante entre milho crioulo e convencional e superior à do Bt. Foi registrado o parasitismo de ovos para a lagarta-da-espiga por Trichogramma pretiosum Riley, nas três cultivares avaliadas, com porcentagens semelhantes entre milho crioulo e convencional e superior em milho Bt. Palavras-chave: Spodoptera frugiperda, Helicoverpa zea, Trichogramma pretiosum, Zea mays, manejo de pragas. INFESTATION IN INLANDRACE, CONVENTIONAL AND TRANSGENIC CORN BY FALL ARMYWORM AND CORN EARWORM, AND EGG PARASITISM ABSTRACT - The objective of the work was to estimate the infestation and eggs parasitism of fall armyworm (J. E. Smith) and corn earworm (Boddie), in three corn varieties: landrace (LomboBaio), conventional hybrid (Semilha S395) and genetically modified hybrid (Bt) (TC1507 Herculex I ®, Cry1F). The experiment was carried out in Santa Maria-RS, during the second-season corn crop, in 2014. The experimental design was a completely randomized block with three treatments, and four replicates. We evaluated the damages, number of larvae, number of eggs and fall armyworm egg parasitism from 9 to 72 days after emergence (DAE). The infestation of corn earworm and the eggs parasitism were measured from 67 to 101 DAE. Fall armyworm damage was similar between landrace and conventional hybrid, and both higher than those of genetically modified hybrid Bt. Average number of fall armyworm larvae was higher in landrace cultivar. The average of total number of corn earworm larvae was similar on landrace and conventional hybrid, both higher than Bt hybrid. Corn earworm eggs parasitism by Trichogramma pretiosum Riley was recorded in the three evaluated cultivars and similar parasitism percentage was observed between landrace and conventional hybrid, which was higher in Bt maize. Keywords: Spodoptera frugiperda, Helicoverpa zea, Trichogramma pretiosum, Zea mays, pest management.

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Combining Ability of Husk Extension, Maysin Content, and Corn Earworm Resistance

Journal of the American Society for Horticultural Science ◽

10.21273/jashs04974-20 ◽

2021 ◽

Vol 146 (1) ◽

pp. 14-23

Author(s):

Virginia M. Moore ◽

William F. Tracy

Keyword(s):

Zea Mays ◽

Combining Ability ◽

Helicoverpa Zea ◽

Sweet Corn ◽

Corn Earworm ◽

Management Options ◽

Mating Design ◽

Cultivar Development ◽

Factorial Mating ◽

Factorial Mating Design

Corn earworm (Helicoverpa zea) is a destructive pest with limited management options in sweet corn (Zea mays) production. Increased husk extension and the presence of the C-glycosyl flavone maysin are two proposed mechanisms for improving corn earworm resistance in corn cultivars. A factorial mating design was conducted to test hybrid combinations of sweet corn inbreds with long husks and/or maysin to identify candidates for future cultivar development. The mating design had seven male parents, including three commercial sweet corn inbreds (Wh9261, We11401, and Wt1001) and four inbreds selected for maysin content (Maysin1, 2, 3, and 4), and five female parents, including two commercial sweet corn inbreds (Ia453su and Ia5125su) and three inbreds with long, thick, tight husks (A684su, A685su, and A686su). Hybrids were evaluated for ear length, husk length, maysin content, and corn earworm resistance at six environments in 2016 and 2017. Relationships between husk extension, maysin, and corn earworm resistance were inconsistent, but five inbreds produced hybrids with significantly lower corn earworm infestation and/or damage, demonstrating potential to confer resistance to the corn earworm.

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Impact of Simulated Corn Earworm (Lepidoptera: Noctuidae) Kernel Feeding on Field Corn Yield

Journal of Economic Entomology ◽

10.1093/jee/toz119 ◽

2019 ◽

Vol 112 (5) ◽

pp. 2193-2198 ◽

Cited By ~ 2

Author(s):

B M Olivi ◽

J Gore ◽

F M Musser ◽

A L Catchot ◽

D R Cook

Keyword(s):

Helicoverpa Zea ◽

Zea Mays L ◽

Corn Earworm ◽

Corn Yield ◽

Corn Hybrids ◽

Field Corn ◽

Lepidoptera Noctuidae ◽

Economic Pest ◽

Harvest Method ◽

Study Manual

Abstract Corn earworm, Helicoverpa zea (Boddie) Lepidoptera: Noctuidae, has not been considered an economic pest of field corn. Historical losses estimates ranged from 1.5 to 2.5%, and a large number of foliar insecticide applications would be needed to minimize infestations. In recent years, Bt, Bacillus thuringiensis (Berliner) field corn, Zea mays (L.) Poales: Poaceae, technologies that exhibit activity against corn earworm have been introduced. However, it is unclear how much damage to corn ears (number of damaged kernels) is required to reduce yield. In this study manual damage methods were utilized to inflict defined levels of kernel damage and to impose damage at levels greater than observed with natural corn earworm infestations. Bt corn hybrids expressing the Agrisure Viptera (Vip 3A) trait were used to minimize injury from natural infestations of corn earworm. Manual kernel damage was imposed at R3 stage to mimic corn earworm feeding while avoiding interference with pollination. These methods were used in experiments where treatments were applied to individual ears and hand-harvested and in experiments where treatments were applied to all primary ears in the plot and machine-harvested. Damage of ≥60 kernels per ear was required to significantly reduce yield regardless of harvest method. Kernel damage from natural corn earworm infestations reported in other studies was much lower than 60 kernels per ear. Timely planting is a key component of all integrated pest management programs. Field corn planted during the recommended planting window for optimum yield is unlikely to experience corn earworm damage great enough to reduce yield.

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Ocorrência de Helicoverpa zea (Lepidoptera: Noctuidae) em híbridos de milho (Zea mays L.) submetidos a diferentes níveis de irrigação

Diversitas Journal ◽

10.17648/diversitas-journal-v4i1.654 ◽

2019 ◽

Vol 4 (1) ◽

pp. 24

Author(s):

João Pedro Ferreira Barbosa ◽

Laryssa Roberta Alves Farias ◽

Paulo Da Silva ◽

Luan Lucas Cardoso Lima ◽

Dacio Rocha Brito ◽

...

Keyword(s):

Zea Mays ◽

Helicoverpa Zea ◽

Zea Mays L ◽

Lepidoptera Noctuidae

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Efeito de genótipos de milho no parasitismo por Trichogramma spp. em ovos de Helicoverpa zea (Boddie)

Anais da Sociedade Entomológica do Brasil ◽

10.1590/s0301-80591998000300012 ◽

1998 ◽

Vol 27 (3) ◽

pp. 435-441 ◽

Cited By ~ 2

Author(s):

Maria J. F. O. Paron ◽

Ivan Cruz ◽

Américo I. Ciociola

Keyword(s):

Zea Mays ◽

Helicoverpa Zea ◽

Zea Mays L ◽

Lepidoptera Noctuidae

Avaliou-se o parasitismo de ovos de Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) por Trichogramma spp., em três genótipos de milho (Zea mays L.): BR 205 (endosperma amarelo normal), BR 451 (endosperma branco, com alta qualidade protéica e BR 400 (endosperma amarelo e doce). Os genótipos foram semeados de duas maneiras: plantio dos três genótipos ao mesmo tempo (1º ensaio) e plantio escalonado com intervalo de uma semana, para coincidir o florescimento, a saber: BR 205, BR 451 e BR 400. Em ambos os plantios não houve efeito dos genótipos na infestação de ovos de H. zea e no parasitismo desses por Trichogramma spp. (média de 8,0 no 1º e de 1,8 ovos/estilo-estigma, no 2ºplantio). O parasitismo dos ovos variou significativamente de acordo com a cultivar, sendo de 62,4% para BR 451, 47,0% para BR 205 e 34,1% para BR 400.

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Pragas e inimigos naturais na soja e no milho cultivados em sistemas diversificados

Scientia Agricola ◽

10.1590/s0103-90162002000400010 ◽

2002 ◽

Vol 59 (4) ◽

pp. 683-687 ◽

Cited By ~ 4

Author(s):

Francisco Jorge Cividanes ◽

Fábio Takeshi Yamamoto

Keyword(s):

Zea Mays ◽

Glycine Max ◽

Helicoverpa Zea ◽

Zea Mays L ◽

Anticarsia Gemmatalis ◽

Glycine Max L

A consorciação de culturas e o plantio direto podem influenciar a dinâmica populacional de insetos, aumentando ou diminuindo a densidade populacional de pragas e de inimigos naturais. Deste modo, avaliaram-se os efeitos de sistemas de plantio direto e da consorciação soja [Glycine max (L.) Merrill] e milho (Zea mays L.) sobre as populações de insetos-pragas e inimigos naturais. Os tratamentos constituíram um fatorial 3x2 (monocultura de soja, monocultura de milho, consorciação soja-milho em plantio direto e plantio convencional). Os insetos foram amostrados pelo método do pano, rede entomológica e procura visual. No milho, a ocorrência de insetos-pragas da parte aérea e insetos predadores não foi influenciada pelo manejo do solo. Lagartas de Helicoverpa zea ocorreram em maior número (5,1) no milho em consorciação. Na soja, adultos de Anticarsia gemmatalis e do predador Cycloneda sanguinea foram mais abundantes em plantio direto, respectivamente, 0,4 e 2,4 insetos. Observou-se maior número do sirfídeo Toxomerus sp. em plantio convencional (1,3). Nas condições de consorciação, verificou-se baixo número de Diabrotica gracilenta (11,5) na soja, enquanto que Maecolaspis sp. (5,0) e Megascelis sp. (17,0) e os predadores C. sanguinea (2,3), Doru sp. (0,8), Geocoris sp. (1,5) e Toxomerus sp. (1,4) ocorreram em alta densidade.

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Effect of Cuticular Lipids From Silks of Selected Corn Genotypes on the Development of Corn Earworm Larvae

Journal of Entomological Science ◽

10.18474/0749-8004-29.2.239 ◽

1994 ◽

Vol 29 (2) ◽

pp. 239-246 ◽

Cited By ~ 3

Author(s):

Guang Yang ◽

B. R. Wiseman ◽

Karl E. Espelie

Keyword(s):

Helicoverpa Zea ◽

Zea Mays L ◽

Control Diet ◽

Larval Growth ◽

Adult Emergence ◽

Corn Earworm ◽

Cuticular Lipids ◽

Cuticular Lipid ◽

Corn Silk ◽

Meridic Diet

Eleven genotypes of corn, Zea mays L., known to vary in their resistance to silk-feeding by larvae of the corn earworm, Helicoverpa zea (Boddie), were used to study the effect of corn silk cuticular lipids on larval growth and development. Growth of the corn earworm was significantly enhanced when larvae were reared on meridic diet containing corn silks from which the cuticular lipids had been removed. Growth of larvae reared on a diet containing unextracted silks from genotypes ‘Stowell's’ ‘Evergreen’, ‘Pioneer 3369A’, and ‘PI340856’ was not affected. When the cuticular lipid extracts of corn silks were added to a meridic diet, no significant differences were found in the weight of 8-day larvae, time to pupation, or days to adult emergence for larvae reared on silks of several corn genotypes. However, the weight of pupae was significantly less when larvae were fed a diet containing cuticular lipids extracted from silks of three corn genotypes ‘Stowell's Evergreen’, ‘GE37’, and ‘Zapalote Chico 2451#(P)C3’ than the weight of pupae from larvae that fed on the control diet.

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Stadia, Larval-Pupal Weight, and Width of Head Capsules of Corn Earworm (Lepidoptera: Noctuidae) After Feeding on Varying Resistance Levels of Maize Silks

Journal of Entomological Science ◽

10.18474/0749-8004-26.3.303 ◽

1991 ◽

Vol 26 (3) ◽

pp. 303-309

Author(s):

B. R. Wiseman ◽

D. J. Isenhour ◽

V. R. Bhagwat

Keyword(s):

Helicoverpa Zea ◽

Zea Mays L ◽

Head Capsule ◽

Developmental Time ◽

Corn Earworm ◽

Pupal Weight ◽

Susceptible Genotype ◽

Resistant Material ◽

Maize Silks ◽

Lepidoptera Noctuidae

Weight of larvae, developmental time to pupation, weight of pupae, length of stadia, and width of head capsule were determined for larvae of the corn earworm, Helicoverpa zea (Boddie), that were fed on meridic diets with silks of ‘Stowell's Evergreen’, a susceptible genotype, or low, intermediate, and high levels of ‘Zapalote Chico’, a corn, Zea mays L., cultivar with antibiotic resistance. As the level of resistance increased, the weight of larvae at 9 days and weight of pupae significantly decreased, and developmental time to pupation significantly increased. Also, as the concentration of resistant material increased in the diet, stadial length also significantly increased. The intermediate and high levels of resistance also resulted in a significant reduction in the width of the head capsule of larvae. Thus, two new characteristics of resistance in maize silks to the corn earworm were identified: increased stadia and decreased width of head capsule.

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Avaliação dos parâmetros genéticos em progênies de meio-irmãos de uma sub-população de milho composto "Flint" para resistência à lagarta-da-espiga Helicoverpa zea (Bod.)

Anais da Sociedade Entomológica do Brasil ◽

10.1590/s0301-80591998000400013 ◽

1998 ◽

Vol 27 (4) ◽

pp. 605-609

Author(s):

Celso R. B. Franchini ◽

Juan T. Ayala-Osuna ◽

Fernando M. Lara ◽

Paulo C. Silva

Keyword(s):

Zea Mays ◽

Helicoverpa Zea ◽

Zea Mays L

Foram estudadas 100 progênies de meio-irmãos de uma sub-população de milho (Zea mays L.) Composto "Flint" com o objetivo de avaliar a resistência de genótipos à lagarta-da-espiga Helicoverpa zea (Bod.). Foram obtidos os valores de danos médios da lagarta-da-espiga de 1,14 cm de comprimento na espiga determinado pela escala de Widstrom e coeficiente de variação experimental (CVE) de 23,4%. Dos parâmetros genéticos avaliados, a estimativa de herdabilidade (h²) foi de 6%, variância genética (VG) de 0,0015 cm² e variância fenotípica (VF) de 0,025 cm² para danos de H. zea. No entanto, o comprimento da ponta da bráctea e compactação da bráctea alcançaram resultados de herdabilidade de 75% e 72% respectivamente. Essa sub-população de milho apresenta variabilidade genética suficiente para utilização em programas de melhoramento, sendo que a resistência à lagarta-da-espiga pode ser obtida através da melhoria dos caracteres morfológicos diretamente relacionados à praga, como a compactação e comprimento da bráctea.

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