Comparison of factors that may affect the inhibitory efficacy of transgenic RNAi targeting of baculoviral genes in silkworm, Bombyx mori

► Resistance to BmNPV by RNAi of viral genes in transgenic silkworm. ► Comprehensive comparison of factors that may affect transgenic RNAi in individual. ► “Head to head” is a better connection pattern of gene fragments and spacer in RNAi. ► The efficiency of IE1 promoter combined with hr3 enhancer is better. ► The immediate early gene was the best target for suppressing viral replication.