Abstract
To counter the threat of insect resistance, Bacillus thuringiensis (Bt) maize growers in the U.S. are required to plant structured non-Bt maize refuges. Concerns with refuge compliance led to the introduction of seed mixtures, also called RIB (refuge-in-the-bag), as an alternative approach for implementing refuge for Bt maize products in the U.S. Maize Belt. A major concern in RIB is cross-pollination of maize hybrids that can cause Bt proteins to be present in refuge maize kernels and negatively affect refuge insects. Here we show that a mixed planting of 5% nonBt and 95% Bt maize containing the SmartStax traits expressing Cry1A.105, Cry2Ab2 and Cry1F did not provide an effective refuge for an important above-ground ear-feeding pest, the corn earworm, Helicoverpa zea (Boddie). Cross-pollination in RIB caused a majority (>90%) of refuge kernels to express ≥ one Bt protein. The contamination of Bt proteins in the refuge ears reduced neonate-to-adult survivorship of H. zea to only 4.6%, a reduction of 88.1% relative to larvae feeding on ears of pure non-Bt maize plantings. In addition, the limited survivors on refuge ears had lower pupal mass and took longer to develop to adults.
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Claims 5
Claim · model-written summary
The 5% nonBt and 95% Bt maize mixture failed to provide an effective corn earworm refuge.
- Treatment
- mixed planting of 5% nonBt and 95% Bt maizee0
- Interactor
- Helicoverpa zea
.jpg?width=60)
Helicoverpa zeae0pest - Outcome
- did not provide an effective refugee0
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
e0“a mixed planting of 5% nonBt and 95% Bt maize containing the SmartStax traits expressing Cry1A.105, Cry2Ab2 and Cry1F did not provide an effective refuge for an important above-ground ear-feeding pest, the corn earworm, Helicoverpa zea (Boddie)”
Claim · model-written summary
Cross-pollination caused over 90% of refuge kernels to express at least one Bt protein.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Cross-pollination in RIB caused a majority (>90%) of refuge kernels to express ≥ one Bt protein”
t0“Maize”
Claim · model-written summary
Bt protein contamination reduced H. zea survival to 4.6%, an 88.1% reduction versus pure non-Bt maize.
- Treatment
- contamination of Bt proteinse0
- Interactor
- H. zeaHelicoverpa zeae0pest
- Outcome
- neonate-to-adult survivorship of H. zeae0
- Direction
- reducede0
- Value
- 4.6%e0
- Qualifier
- a reduction of 88.1%e0
- Comparator
- pure non-Bt maize plantingse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The contamination of Bt proteins in the refuge ears reduced neonate-to-adult survivorship of H. zea to only 4.6%, a reduction of 88.1% relative to larvae feeding on ears of pure non-Bt maize plantings”
Claim · model-written summary
Surviving H. zea on refuge ears had lower pupal mass.
- Interactor
- Corn EarwormHelicoverpa zeat0pest
- Outcome
- pupal masse0
- Direction
- lowere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the limited survivors on refuge ears had lower pupal mass”
t0“Maize: Impact of Cross-Pollination on an Ear-Feeding Pest, Corn Earworm”
Claim · model-written summary
Surviving H. zea on refuge ears took longer to develop to adults.
- Interactor
- Corn EarwormHelicoverpa zeat0pest
- Outcome
- develop to adultse0
- Direction
- longere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the limited survivors on refuge ears had lower pupal mass and took longer to develop to adults”
t0“Maize: Impact of Cross-Pollination on an Ear-Feeding Pest, Corn Earworm”
The same questions in other papers
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