Effects of Pink Bollworm Resistance to Bacillus thuringiensis on Phenoloxidase Activity and Susceptibility to Entomopathogenic Nematodes

dc.contributor.author Gassmann, Aaron
dc.contributor.author Fabrick, Jeffrey
dc.contributor.author Gassmann, Aaron
dc.contributor.author Sisterson, Mark
dc.contributor.author Hannon, Eugene
dc.contributor.author Stock, S.
dc.contributor.author Carriere, Yves
dc.contributor.author Tabashnik, Bruce
dc.contributor.department Entomology
dc.date 2018-02-14T18:33:07.000
dc.date.accessioned 2020-06-30T02:22:15Z
dc.date.available 2020-06-30T02:22:15Z
dc.date.embargo 2014-09-26
dc.date.issued 2009-06-01
dc.description.abstract <p>Widespread planting of crops genetically engineered to produce insecticidal toxins from the bacterium <em>Bacillus thuringiensis</em> (Bt) imposes selection on many key agricultural pests to evolve resistance to Bt. Fitness costs can slow the evolution of Bt resistance. We examined effects of entomopathogenic nematodes on fitness costs of Bt resistance in the pink bollworm,<em>Pectinophora gossypiella</em> (Saunders) (Lepidoptera: Gelechiidae), a major pest of cotton,<em>Gossypium hirsutum</em> L., in the southwestern United States that is currently controlled by transgenic cotton that produces Bt toxin Cry1Ac. We tested whether the entomopathogenic nematodes <em>Steinernema riobrave</em> Cabanillas, Poinar, and Raulston (Rhabditida: Steinernematidae) and <em>Heterorhabditis bacteriophora</em> Poinar (Rhabditida: Heterorhabditidae) affected fitness costs of resistance to Cry1Ac in two laboratory-selected hybrid strains of pink bollworm reared on non-Bt cotton bolls. The nematode <em>S. riobrave</em> imposed a recessive fitness cost for one strain, and <em>H. bacteriophora</em> imposed a fitness cost affecting heterozygous resistant individuals for the other strain. Activity of phenoloxidase, an important component of insects' immune response, did not differ between Bt-resistant and Bt-susceptible families. This suggests phenoloxidase does not affect susceptibility to entomopathogenic nematodes in Bt-resistant pink bollworm. Additionally, phenoloxidase activity does not contribute to Bt resistance, as has been found in some species. We conclude that other mechanisms cause higher nematode-imposed mortality for pink bollworm with Bt resistance genes. Incorporation of nematode-imposed fitness costs into a spatially explicit simulation model suggests that entomopathogenic nematodes in non-Bt refuges could delay resistance by pink bollworm to Bt cotton.</p>
dc.description.comments <p>This article is from <em>Journal of Economic Entomology </em>102 (2009): 1224, doi:<a href="http://dx.doi.org/10.1603/029.102.0348" target="_self">10.1603/029.102.0348</a>. </p>
dc.format.mimetype application/pdf
dc.identifier archive/lib.dr.iastate.edu/ent_pubs/182/
dc.identifier.articleid 1185
dc.identifier.contextkey 6171768
dc.identifier.s3bucket isulib-bepress-aws-west
dc.identifier.submissionpath ent_pubs/182
dc.identifier.uri https://dr.lib.iastate.edu/handle/20.500.12876/23787
dc.language.iso en
dc.source.bitstream archive/lib.dr.iastate.edu/ent_pubs/182/2009_Gassmann_EffectsPink.pdf|||Fri Jan 14 21:38:19 UTC 2022
dc.source.uri 10.1603/029.102.0348
dc.subject.disciplines Agronomy and Crop Sciences
dc.subject.disciplines Entomology
dc.subject.disciplines Plant Pathology
dc.subject.disciplines Systems Biology
dc.subject.keywords biological control
dc.subject.keywords fitness cost
dc.subject.keywords immune response
dc.subject.keywords integrated resistance management
dc.subject.keywords simulation modeling
dc.title Effects of Pink Bollworm Resistance to Bacillus thuringiensis on Phenoloxidase Activity and Susceptibility to Entomopathogenic Nematodes
dc.type article
dc.type.genre article
dspace.entity.type Publication
relation.isAuthorOfPublication 59bd52a0-183d-4ea1-b353-4b07440b1e9f
relation.isOrgUnitOfPublication f47c8cad-50be-4fb0-8870-902ff536748c
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