Abstract
A recent shift in managing insect resistance to genetically engineered (GE) maize consists of mixing non-GE seed with GE seed known as "refuge in a bag", which increases the likelihood of predators encountering both prey fed Bt and prey fed non-Bt maize. We therefore conducted laboratory choice-test feeding studies to determine if a predator, Harmonia axyridis, shows any preference between prey fed Bt and non-Bt maize leaves. The prey species was Spodoptera frugiperda, which were fed Bt maize (MON-810), expressing the single Cry1Ab protein, or non-Bt maize. The predators were third instar larvae and female adults of H. axyridis. Individual predators were offered Bt and non-Bt fed prey larvae that had fed for 24, 48 or 72 h. Ten and 15 larvae of each prey type were offered to third instar and adult predators, respectively. Observations of arenas were conducted at 1, 2, 3, 6, 15 and 24 h after the start of the experiment to determine the number and type of prey eaten by each individual predator. Prey larvae that fed on non-Bt leaves were significantly larger than larvae fed Bt leaves. Both predator stages had eaten nearly all the prey by the end of the experiment. However, in all combinations of predator stage and prey age, the number of each prey type consumed did not differ significantly. ELISA measurements confirmed the presence of Cry1Ab in leaf tissue (23-33 µg/g dry weight) and S. frugiperda (2.1-2.2 µg/g), while mean concentrations in H. axyridis were very low (0.01-0.2 µg/g). These results confirm the predatory status of H. axyridis on S. frugiperda and that both H. axyridis adults and larvae show no preference between prey types. The lack of preference between Bt-fed and non-Bt-fed prey should act in favor of insect resistance management strategies using mixtures of GE and non-GE maize seed.
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Claims 9
Claim · model-written summary
Prey larvae fed non-Bt maize leaves were significantly larger than larvae fed Bt maize leaves.
- Treatment
- fed Bt leavese2
- Interactor
- Spodoptera frugiperda
.jpg?width=60)
Spodoptera frugiperdae0pest - Outcome
- Prey larvaee2
- Direction
- largere2
- Comparator
- non-Bt leavese2
Zea maysOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“Non-Bt Maize”
e0“The prey species was Spodoptera frugiperda”
e2“Prey larvae that fed on non-Bt leaves were significantly larger than larvae fed Bt leaves”
Claim · model-written summary
Predators did not differ in the number of Bt-fed and non-Bt-fed prey consumed.
- Treatment
- Bt-fede7
- Interactor
- Spodoptera frugiperdaSpodoptera frugiperdae0pest
- Second interactor
- H. axyridis
.jpg?width=60)
Harmonia axyridise1biocontrol_agent - Outcome
- the number of each prey type consumede3
- Direction
- did not differe3
- Comparator
- non-Bt-fed preye7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
.jpg?width=500)
Verbatim
t0“Non-Bt Maize”
e0“The prey species was Spodoptera frugiperda”
e1“The predators were third instar larvae and female adults of H. axyridis”
e3“in all combinations of predator stage and prey age, the number of each prey type consumed did not differ significantly”
e7“The lack of preference between Bt-fed and non-Bt-fed prey should act in favor of insect resistance management strategies using mixtures of GE and non-GE maize seed”
Claim · model-written summary
Both predator stages had eaten nearly all the prey by the end of the experiment.
- Interactor
- Spodoptera frugiperdaSpodoptera frugiperdae0pest
- Second interactor
- H. axyridisHarmonia axyridise1biocontrol_agent
- Outcome
- nearly all the preye6
- Qualifier
- by the end of the experimente6
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Non-Bt Maize”
e0“The prey species was Spodoptera frugiperda”
e1“The predators were third instar larvae and female adults of H. axyridis”
e6“Both predator stages had eaten nearly all the prey by the end of the experiment”
Claim · model-written summary
Cry1Ab was detected in maize leaf tissue at 23-33 µg/g dry weight.
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Non-Bt Maize”
e4“ELISA measurements confirmed the presence of Cry1Ab in leaf tissue (23-33 µg/g dry weight) and S. frugiperda (2.1-2.2 µg/g), while mean concentrations in H. axyridis were very low (0.01-0.2 µg/g)”
Claim · model-written summary
Cry1Ab was detected in Spodoptera frugiperda prey at 2.1-2.2 µg/g.
- Interactor
- S. frugiperdaSpodoptera frugiperdae4pest
- Gene
- Cry1Abe4
- Outcome
- presencee4
- Value
- 2.1-2.2 µg/ge4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Non-Bt Maize”
e4“ELISA measurements confirmed the presence of Cry1Ab in leaf tissue (23-33 µg/g dry weight) and S. frugiperda (2.1-2.2 µg/g), while mean concentrations in H. axyridis were very low (0.01-0.2 µg/g)”
Claim · model-written summary
Mean Cry1Ab concentrations in H. axyridis were very low, 0.01-0.2 µg/g.
- Interactor
- H. axyridisHarmonia axyridise4biocontrol_agent
- Gene
- Cry1Abe4
- Outcome
- mean concentrationse4
- Value
- 0.01-0.2 µg/ge4
- Qualifier
- very lowe4
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Non-Bt Maize”
e4“ELISA measurements confirmed the presence of Cry1Ab in leaf tissue (23-33 µg/g dry weight) and S. frugiperda (2.1-2.2 µg/g), while mean concentrations in H. axyridis were very low (0.01-0.2 µg/g)”
Claim · model-written summary
The predatory status of H. axyridis on S. frugiperda was confirmed.
- Interactor
- S. frugiperdaSpodoptera frugiperdae5pest
- Second interactor
- H. axyridisHarmonia axyridise5biocontrol_agent
- Outcome
- predatory status of H. axyridis on S. frugiperdae5
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Non-Bt Maize”
e5“These results confirm the predatory status of H. axyridis on S. frugiperda and that both H. axyridis adults and larvae show no preference between prey types”
Claim · model-written summary
Both H. axyridis adults and larvae showed no preference between Bt-fed and non-Bt-fed prey.
- Treatment
- Bt-fede7
- Interactor
- H. axyridisHarmonia axyridise5biocontrol_agent
- Outcome
- preferencee5
- Direction
- no preferencee5
- Comparator
- non-Bt-fed preye7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Non-Bt Maize”
e5“These results confirm the predatory status of H. axyridis on S. frugiperda and that both H. axyridis adults and larvae show no preference between prey types”
e7“The lack of preference between Bt-fed and non-Bt-fed prey should act in favor of insect resistance management strategies using mixtures of GE and non-GE maize seed”
Claim · model-written summary
The lack of preference between Bt-fed and non-Bt-fed prey should favour insect resistance management strategies that mix GE and non-GE maize seed.
- Outcome
- insect resistance management strategiese7
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e7“The lack of preference between Bt-fed and non-Bt-fed prey should act in favor of insect resistance management strategies using mixtures of GE and non-GE maize seed”
The same questions in other papers
transgenic · Spodoptera frugiperda · Zea mays (maize)Positive and negative results
13 papers in the same direction as this paper · 2 in the opposite direction
- negative
- negative
- positive
12 papers more in this group
See all 16 papers →transgenic · Harmonia axyridis · Zea mays (maize)Results agree
1 paper in the same direction as this paper
- no effect
Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.