No bioaccumulation of Cry protein in the aphidophagous predator Harmonia axyridis

The uptake of insecticidal Cry1Ab from genetically engineered (GE) maize, via herbivore Rhopalosiphum padi, to a predator Harmonia axyridis and its potential intergenerational transfer were investigated. Cry1Ab concentration was found to be 400-fold lower in R. padi compared to GE maize, and more than two-fold lower in H. axyridis. For 62% of H. axyridis samples, Cry1Ab was under the limit of detection (LOD), for another 13% were under the limit of quantification (LOQ). The concentration of Cry1Ab was similar between H. axyridis exposed short-term and long-term with the exception of adults after long-term. There was no correlation between Cry1Ab in females and eggs and neonates. The performance of H. axyridis was comparable between Cry1Ab and control. Histological investigation did not show any pathological changes in the digestive and reproductive systems. The detected route of exposure is unlikely to be important for functional biological control by H. axyridis in agroecosystem.

Automated summary

The uptake and potential intergenerational transfer of Cry1Ab insecticide from genetically engineered maize to the predator Harmonia axyridis were investigated. Cry1Ab concentration was significantly lower in the herbivore Rhopalosiphum padi and the predator H. axyridis compared to GE maize. Cry1Ab did not affect the performance or cause any pathological changes in H. axyridis, suggesting that the detected route of exposure is unlikely to impact the biological control of this predator in agroecosystems.