Short-term carbon allocation and root lignin of Cry3Bb Bt and NonBt corn in the presence of corn rootworm

► We investigated C allocation and lignin contents in Cry3Bb Bt and NonBt corn as affected by corn rootworm (CRW) infestation. ► No significant genotype effect was observed on measured variables without CRW infestation. ► With CRW, the percentage of fixed 13C allocated to NonBt roots was significantly lower than to Bt roots. ► The lignin content in NonBt roots was significantly higher with than without CRW. ► These observed effects of CRW resistance in Bt corn may have implications for soil C balance in the presence of CRW.