Abstract
We analyzed part of the sodium channel gene to clarify the molecular mechanism involved in the pyrethroid resistance of the yellow tea thrips (Scirtothrips dorsalis), and found two amino acid mutations (T929I and L1014F) known as pyrethroid-resistant factors in several other insects. The L1014F mutation was shared with all the tested thrips from a field colony. On the other hand, the T929I mutation was found only in individuals which survived in pyrethroid treatment of agriculturally recommended concentration. This might suggest that pyrethroid resistance of S. dorsalis in the field is conferred by both mutations. We developed the PCR-RFLP assay using MboI to distinguish pyrethroid-resistant individuals.
