Effects of mCry51Aa2-producing cotton on the non-target spider mite Tetranychus urticae and the predatory bug Orius majusculus
Pierce-sucking insects, such as plant bugs or stink bugs, cause damage in cotton fields worldwide. A novel genetically engineered (GE) cotton ( Gossypium hirsutum ) is protected against hemipteran pests and thrips by producing the modified Bacillus thuringiensis ( Bt ) mCry51Aa2 protein. Herbivores...
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Published in | Journal of pest science Vol. 94; no. 2; pp. 351 - 362 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Berlin/Heidelberg
Springer Berlin Heidelberg
01.03.2021
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | Pierce-sucking insects, such as plant bugs or stink bugs, cause damage in cotton fields worldwide. A novel genetically engineered (GE) cotton (
Gossypium hirsutum
) is protected against hemipteran pests and thrips by producing the modified
Bacillus thuringiensis
(
Bt
) mCry51Aa2 protein. Herbivores that consume insect-protected GE crops, and their natural enemies, can be exposed to plant-produced insecticidal proteins. We investigated tritrophic interactions to evaluate the potential impact of the novel
Bt
cotton on a non-target herbivore, the spider mite
Tetranychus urticae
, and on a generalist predator, the pirate bug
Orius majusculus
. Pirate bugs belong to the same insect order as the target pests and might thus be adversely affected by mCry51Aa2. Enzyme-linked immunosorbent assays showed that levels of mCry51Aa2 in
T. urticae
were one order of magnitude, and those in
O. majusculus
were three orders of magnitude lower than in
Bt
cotton leaves.
O. majusculus
nymphs fed with spider mites collected from
Bt
cotton had lower survival, increased developmental time, and reduced fecundity compared to nymphs fed spider mites from non-
Bt
near-isogenic cotton. Because
Bt
cotton did not affect the survival and growth of the spider mites, we conclude that indirect prey-quality mediated effects of the
Bt
cotton on the predatory bugs are unlikely and that
O. majusculus
are directly affected by the
Bt
protein. Follow-up studies are indicated to assess whether the effects observed under worst-case conditions are mitigated under more realistic exposure conditions where alternative prey with low
Bt
protein levels is available. |
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ISSN: | 1612-4758 1612-4766 |
DOI: | 10.1007/s10340-020-01260-4 |