Why Rice Planthoppers Do Not Prefer Bt Rice Plants

Insect resistant Bt rice lines have been developed in China. Field surveys showed that Bt rice plants have less rice planthoppers (Nilapavata lugens) than non-Bt rice, although planthoppers are not targeted by the insecticidal proteins in Bt rice. Thus, Xingyun Wang of the Chinese Academy of Agricultural Sciences and colleagues conducted an investigation about the mechanisms underlying this phenomenon.

Results showed that the low number of planthoppers on Bt rice is linked to decreased caterpillar damage. Laboratory, field-cage, and open-field experiments showed that rice planthoppers had no feeding preference for undamaged Bt or non-Bt plants, but had a strong preference for caterpillar-damaged Bt or non-Bt plants. Further analyses showed that caterpillar damage caused the release plant volatiles attractive to planthoppers.

The researchers recommended the use of non-Bt rice refuges to serve as a trap crop for planthoppers and also to delay the development of Bt resistance.

Read the research article in Plant Biotechnology Journal.