Susceptibility of Brazilian Populations of Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) to Vip3Aa20

2017 ◽  
Vol 111 (1) ◽  
pp. 399-404 ◽  
Author(s):  
N A Leite ◽  
R M Pereira ◽  
M R Durigan ◽  
D Amado ◽  
J Fatoretto ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae ◽  
Brazilian Populations

scholarly journals Desenvolvimento de Helicoverpa spp. em milho Bt com expressão de diferentes proteínas

2016 ◽  
Vol 51 (5) ◽  
pp. 537-544
Author(s):  
Christiane Almeida dos Santos ◽  
Rosangela Cristina Marucci ◽  
Tatiane Aparecida Nascimento Barbosa ◽  
Octavio Gabryel Araujo ◽  
José Magid Waquil ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae

Resumo: O objetivo deste trabalho foi avaliar os aspectos biológicos de Helicoverpa zea e Helicoverpa armigera (Lepidoptera: Noctuidae) em híbridos de milho com expressão de diferentes proteínas. Foram avaliadas as proteínas Cry1F, Cry1A(b), Cry1A.105 + Cry2Ab2 e Vip3A e seus respectivos isogênicos convencionais. As larvas foram alimentadas com espiguetas de milho Bt e convencional, trocadas a cada dois dias. Os parâmetros avaliados foram: sobrevivência 48 horas após eclosão, sobrevivência larval, peso de larvas e de pupas, período de desenvolvimento larval e período pré-imaginal. Observou-se efeito significativo da interação entre evento de milho Bt e espécie de Helicoverpa para todas as variáveis biológicas avaliadas. Larvas de H. armigera apresentaram maior sobrevivência 48 horas após eclosão em milho expressando a proteína Cry1F e a Vip3 em relação a H. zea. O período letal foi maior em H. armigera do que em H. zea, mas, em milho com expressão da proteína Cry1A(b), foi quatro vezes menor. Não houve sobrevivente para ambas as espécies de Helicoverpa em nenhum dos híbridos Bt avaliados. Nos isogênicos convencionais, o índice de adaptação de H. armigera foi superior ao de H. zea, o que indica maior facilidade de adaptação ao ambiente dessa espécie.

scholarly journals Efficacy of Helicoverpa Armigera Nucleopolyhedrovirus on Soybean for Control of Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) in Arkansas Agriculture

Insects ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 91
Author(s):  
Joseph L. Black ◽  
Gus M. Lorenz ◽  
Aaron J. Cato ◽  
Nick R. Bateman ◽  
Nicholas J. Seiter
Keyword(s):  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
Larval Instar ◽  
Instar Larva ◽  
Naturally Occurring ◽  
Action Threshold ◽  
Helicoverpa Armígera ◽  
New Formulation ◽  
Mean Time ◽  
Lepidoptera Noctuidae

Helicoverpa armigera nucleopolyhedrovirus (HearNPV) is a naturally occurring virus commercially produced for control of Heliothines, including Helicoverpa zea. One drawback with using this virus for control has been the slower time to mortality compared with synthetic insecticides. However, a new formulation (Heligen®) has anecdotally been thought to result in quicker mortality than previously observed. The objective of this study was to evaluate percent defoliation, the efficacy of HearNPV on mortality for each H. zea larval instar, and the potential for control of a second infestation. Fourteen days after the first infestation, all plants were re-infested with a second instar larva to simulate a second infestation. Helicoverpa armigera nucleopolyhedrovirus was effective at killing 1st–3rd instars, resulting in 99% mortality over 4–6 days. However, 4th and 5th instar mortality only reached 35%. Second infestation larvae died between 3.4 and 3.8 days, significantly faster than the 1st infestation of 2nd instars, which had a mean time to mortality of 4.9 days. An increase in mortality rate is probably due to increasing viral concentrations after viral replication within the first hosts. Final defoliation percentages were significantly smaller in the treated plants versus the untreated plants. Only 3rd and 4th instar larvae caused percent defoliation to exceed the current Arkansas action threshold of 40%. Helicoverpa armigera nucleopolyhedrovirus in the Heligen formulation can control 1st–3rd instars within 4–6 days, while keeping defoliation below the action threshold of 40%.

scholarly journals Comparative Toxicity of Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) to Selected Insecticides

Insects ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 431 ◽  
Author(s):  
Fernando R. da Silva ◽  
Dario Trujillo ◽  
Oderlei Bernardi ◽  
Jose Carlos Verle Rodrigues ◽  
Woodward D. Bailey ◽  
...  
Keyword(s):  
Puerto Rico ◽  
Acute Toxicity ◽  
Insecticide Resistance ◽  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
Corn Earworm ◽  
Median Lethal Concentration ◽  
Helicoverpa Armígera ◽  
Old World Bollworm ◽  
Lepidoptera Noctuidae

Until recently, the Old World bollworm (OWB) Helicoverpa armigera (Hübner) and the corn earworm Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae) were geographically isolated. Both species are major pests of agricultural commodities that are known to develop insecticide resistance, and they now coexist in areas where H. armigera invaded the Americas. This is the first study to compare the susceptibility of the two species to conventional insecticides. The susceptibility of third instar H. armigera and H. zea larvae to indoxacarb, methomyl, spinetoram, and spinosad was determined using a diet-overlay bioassay in a quarantine laboratory in Puerto Rico. Mortality was assessed at 48 h after exposure for up to eight concentrations per insecticide. Spinetoram exhibited the highest acute toxicity against H. armigera, with a median lethal concentration (LC50) of 0.11 µg a.i./cm2, followed by indoxacarb and spinosad (0.17 µg a.i./cm2 for both) and methomyl (0.32 µg a.i./cm2). Spinetoram was also the most toxic to H. zea (LC50 of 0.08 µg a.i./cm2), followed by spinosad (0.17 µg a.i./cm2) and methomyl (0.18 µg a.i./cm2). Indoxacarb was the least toxic to H. zea, with an LC50 of 0.21 µg a.i./cm2. These findings could serve as a comparative reference for monitoring the susceptibility of H. armigera and H. zea to indoxacarb, methomyl, spinetoram, and spinosad in Puerto Rico, and may facilitate the detection of field-selected resistance for these two species and their potential hybrids in areas recently invaded by H. armigera.

scholarly journals Battle in the New World: Helicoverpa armigera versus Helicoverpa zea (Lepidoptera: Noctuidae)

PLoS ONE ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. e0167182 ◽  
Author(s):  
José P. F. Bentivenha ◽  
Silvana V. Paula-Moraes ◽  
Edson L. L. Baldin ◽  
Alexandre Specht ◽  
Ivana F. da Silva ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
New World ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae

Pan-American Similarities in Genetic Structures of Helicoverpa armigera and Helicoverpa zea (Lepidoptera: Noctuidae) With Implications for Hybridization

2017 ◽  
Vol 46 (4) ◽  
pp. 1024-1034 ◽  
Author(s):  
N. A. Leite ◽  
A. S. Correa ◽  
A. P. Michel ◽  
A. Alves-Pereira ◽  
V.A.C. Pavinato ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Helicoverpa Zea ◽  
Helicoverpa Armígera ◽  
Pan American ◽  
Genetic Structures ◽  
Lepidoptera Noctuidae
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