The relative expression levels of 5 candidate RNAi target genes upon feeding on artificial diet containing dsRNAs at different time point. The dsRNAs were supplied to the artificial diet at concentration of 7.5 ng/μl. qRT-PCRs were performed using the total RNA from the survived instars at different time point after feeding on artificial diet containing the respective dsRNAs. The relative expression levels of 5 RNAi target genes were monitored at indicated time point in an 8 d period. The expression of Unigene 8273, Unigene 23028 and Unigene 28469 was knocked down significantly after dsRNA feeding at day 6, with the latter two genes completely silenced at day 8. (*Student’s t-test, n=3, p<0.05; **Student’s t-test, n=3, p<0.01).