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

Leite, Natália Alves; Pereira, Rogério Machado; Durigan, Mariana Regina; Amado, Douglas; Fatoretto, Júlio; Medeiros, Fernanda Carvalho Lopes; Omoto, Celso

doi:10.1093/jee/tox336

Cited by 19 publications

(20 citation statements)

References 38 publications

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“…We found a low number of putative hybrids between H. armigera and H. zea Brazilian strains under natural conditions. This result agrees with the previous studies that suggest low hibridization between H. armigera and H. zea in Brazil (Anderson et al, , ; Leite, Pereira, et al, . However, Brazilian agroecosystems show abrupt changes of cultivated area size, crop species, and pest management strategies (e.g., Bt crop events), which may rapidly modify the hybridization dynamic between H. armigera and H. zea .…”

Section: Discussionsupporting

confidence: 92%

Invasion origin, rapid population expansion, and the lack of genetic structure of cotton bollworm (Helicoverpa armigera) in the Americas

Gonçalves

Mastrangelo

Rodrigues

et al. 2019

Ecology and Evolution

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In 2013, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) was officially declared as present in Brazil and, after two years, the species was detected in the Caribbean and North America. Information on genetic features and accurate distribution of pests is the basis for agricultural protection policies. Furthermore, such knowledge is imperative to develop control strategies, understand the geographical range, and genetic patterns of this species in the Americas. Here, we carried out the widest sampling of H. armigera in the South American continent and Puerto Rico, after we estimated the diversity, demographic parameters, and genetic structure. The Internal Transcribed Spacer 1 (ITS1) nuclear marker was used to investigate the presence of putative hybrids between H. armigera and H. zea, and they were observed at a frequency of 1.5%. An ABC analysis, based in COI gene fragment, suggested Europe as the origin of South America specimens of H. armigera and following a movement northward through the Caribbean. Three mtDNA genes and three nDNA markers revealed high genetic diversity distributed without the defined population structure of H. armigera in South America. Most of the genetic variation is within populations with a multidirectional expansion of H. armigera among morphoclimatic regions. High genetic diversity, rapid population expansion, and hybridization have implications for pest management since they suggest that adaptive alleles are spread through wide areas in South America that favor rapid local adaptation of H. armigera to new and disturbed environments (e.g., in agricultural areas).

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Section: Discussionsupporting

confidence: 92%

Invasion origin, rapid population expansion, and the lack of genetic structure of cotton bollworm (Helicoverpa armigera) in the Americas

Gonçalves

Mastrangelo

Rodrigues

et al. 2019

Ecology and Evolution

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“…The triple-gene Bt cotton that expressed Vip3Aa (Cry1Ac+Cry1F+Vip3Aa19, Cry1Ac+Cry2Ab+Vip3Aa19, or Cry1Ab+Cry2Ae+Vip3Aa19) caused 100% larval mortality in all H. zea populations, which reinforces the high efficacy of this toxin for H. zea control [18,22]. These results suggest a low frequency of resistant alleles to Vip3A in H. zea populations tested.…”

Section: Discussionsupporting

confidence: 54%

“…However, the cotton bollworm, H. zea is less susceptible to Cry toxins expressed in cotton and corn, which, therefore, do not satisfy high-dose criteria [17]. Toxicological bioassays performed with populations of H. zea from the southeastern U.S., including populations from the Florida Panhandle, have indicated a decrease in susceptibility of H. zea populations to Cry1Ab, Cry1Ac, Cry1A.105, and Cry2Ab, but not to Vip3Aa [5,[18][19][20]. However, a major resistance allele conferring high levels of Vip3Aa resistance in a field-derived strain of H. zea in Texas has been recently reported [21].…”

Section: Introductionmentioning

confidence: 99%

Demographic Performance of Helicoverpa zea Populations on Dual and Triple-Gene Bt Cotton

Rabelo

Paula‐Moraes

Pereira

et al. 2020

Toxins

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Insecticidal toxins from Bacillus thuringiensis (Bt) are valuable tools for pest management worldwide, contributing to the management of human disease insect vectors and phytophagous insect pests of agriculture and forestry. Here, we report the effects of dual and triple Bt toxins expressed in transgenic cotton cultivars on the fitness and demographic performance of Helicoverpa zea (Boddie)—a noctuid pest, known as cotton bollworm and corn earworm. Life-history traits were determined for individuals of three field populations from a region where H. zea overwintering is likely. Triple-gene Bt cotton cultivars that express Cry and Vip3Aa toxins killed 100% of the larvae in all populations tested. In contrast, dual-gene Bt cotton that express Cry1Ac+Cry1F and Cry1Ac+Cry2Ab allowed population growth with the intrinsic rate of population growth (rm) 38% lower than on non-Bt cotton. The insects feeding on Bt cotton plants that express Cry1Ac+Cry2Ab, Cry1Ac+Cry1F, or Cry1Ab+Cry2Ae exhibited reduced larval weight, survival rate, and increased development time. Additionally, fitness parameters varied significantly among the insect populations, even on non-Bt cotton plants, likely because of their different genetic background and/or previous Bt toxin exposure. This is the first report of the comparative fitness of H. zea field populations on dual-gene Bt cotton after the recent reports of field resistance to certain Bt toxins. These results document the population growth rates of H. zea from an agricultural landscape with 100% Bt cotton cultivars. Our results will contribute to the development and validation of resistance management recommendations.

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“…High susceptibility to Cry1Ac of Helicoverpa armigera has also been documented in Brazil [10]. However, due to H. armigera having low susceptibility to Vip3Aa20, Leite et al [19] highlight that it is extremely important to monitor the susceptibility of H. armigera populations, when crops such as cotton are expressing Vip3Aa20 protein. Although Bt crops can reduce the insecticide sprays to control lepidopteran pests [20,21], on average, in Brazil, it is still necessary to spray insecticides 7 to 9 times in cotton [22].…”

Section: Introductionmentioning

confidence: 99%

Shifts in Ecological Dominance between Two Lepidopteran Species in Refuge Areas of Bt Cotton

Malaquias

Santana

Degrande

et al. 2021

Insects

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Competition behavior involving agricultural pest species has long been viewed as a powerful selective force that drives ecological and phenotypic diversity. In this context, a Game Theory-based approach may be useful to describe the decision-making dilemma of a competitor with impacts to guarantee its superiority in terms of ecological dominance or sharing of the food resource with its competitor. In an attempt to elucidate the consequences of competitive dynamics for the ecological dominance of these species in refuge areas of Bt cotton, we conducted a study that was divided into two parts. The first study consisted of an evaluation of interactions involving Spodoptera frugiperda (JE Smith, 1797) and Helicoverpa armigera (Hübner, 1808) on non-Bt cotton plants in a field trial. In the second study, we explored the data matrix collected in the field to parameterize a model of Cellular Automata (CA) with update rules inspired by Game Theory. Computer simulations were analyzed in hypothetical scenarios involving the application (or not) of insecticides in the refuge areas in combination with the resistance factor of one or both pest species to the insecticides used in the refuge areas. H. armigera had superior competitive performance in relation to S. frugiperda only at high densities. According to the density-mediated shift in dominance of the species, the resistance of S. frugiperda to insecticides is seen as a risk factor for the production of susceptible individuals of H. armigera on a large scale in the refuge areas. Additionally, S. frugiperda insecticide resistance may potentially impact the resistance evolution of the H. armigera population to Bt cotton. Thus, ecological dominance could diverge by the presence of a resistance allele to insecticides with interspecific competition perhaps subordinate to evolutionary processes.

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

Cited by 19 publications

References 38 publications

Invasion origin, rapid population expansion, and the lack of genetic structure of cotton bollworm (Helicoverpa armigera) in the Americas

Invasion origin, rapid population expansion, and the lack of genetic structure of cotton bollworm (Helicoverpa armigera) in the Americas

Demographic Performance of Helicoverpa zea Populations on Dual and Triple-Gene Bt Cotton

Shifts in Ecological Dominance between Two Lepidopteran Species in Refuge Areas of Bt Cotton

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