Journal of Economic Entomology (2017) 110, 1317-1325
Z. Svobodová, E.C. Burkness, O. Skoková Habustová and W.D. Hutchison (2017)
Predator preference for Bt-fed Spodoptera frugiperda (Lepidoptera: Noctuidae) prey: Implications for insect resistance management in Bt maize seed blends
Journal of Economic Entomology 110 (3), 1317-1325
Abstract: Understanding indirect, trophic-level effects of genetically engineered plants, expressing insecticidal proteins derived from the bacterium, Bacillus thuringiensis (Bt), is essential to the ecological risk assessment process. In this study, we examine potential indirect, trophic-level effects of Bt-sensitive prey using the predator, Harmonia axyridis (Pallas), feeding upon Spodoptera frugiperda (J.E. Smith) larvae, which had delayed development (lower body mass) following ingestion of Cry1Ab maize leaves. We found no adverse effects on development and survival when H. axyridis larvae were fed S. frugiperda larvae that had fed on Cry1Ab maize tissue. Presence of Cry1Ab in H. axyridis decreased considerably after switching to another diet within 48 h. In a no-choice assay, H. axyridis larvae consumed more Bt-fed S. frugiperda than non-Bt-fed larvae. Preference for S. frugiperda feeding on Bt maize was confirmed in subsequent choice assays with H. axyridis predation on Bt-fed, 1–5-d-old S. frugiperda larvae. We suggest that H. axyridis preferred prey, not based on whether it had fed on Bt or non-Bt maize, but rather on larval mass, and they compensated for the nutritional deficiency of lighter larvae through increased consumption. Pest larvae with variable levels of resistance developing on Bt diet are often stunted versus sensitive larvae developing on non-Bt diet. It is possible that such larvae may be preferentially removed from local field populations. These results may have implications for insect resistance management and may be played out under field conditions where seed blends of Bt and non-Bt hybrids are planted.
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Link to article at publishers website
Database assignments for author(s): Eric C. Burkness, William (Bill) D. Hutchison
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
non-target effects/fate in environm.
Pest and/or beneficial records:
|Spodoptera frugiperda||Maize/corn (Zea mays)|
|Bacillus thuringiensis genes in crops (entomopathogen)||Spodoptera frugiperda|
|Bacillus thuringiensis Cry1A-toxin (entomopathogen)||Spodoptera frugiperda|