Status of insecticide resistance and associated mutations in Q-biotype of whitefly, Bemisia tabaci, from eastern China

Resistance levels in five field strains of Bemisia tabaci Q-biotype in eastern China to six representative insecticides were determined, and the frequencies of synaptic acetylcholinesterase ace1 mutation (F331W) and para-type voltage gated sodium channel mutations (L925I and T929V) were detected using polymerase chain reaction-based monitoring techniques. Compared with the reference strain, the field strains exhibited low to high resistance to two neonicotinoids (RF 8.68-75 for imidacloprid and 7.48-46.40 for nitenpyram). Low resistance to dichlorvos (RF 1.37-2.83) and cypermethrin (RF 2.61-8.69) were observed in these strains. All strains were susceptible to abamectin and carbosulfan. The F331W mutation in ace1 gene was fixed in all field strains, the frequencies of the L925I mutation and T929V mutation in sodium channel gene were in the range of 39.6-70% and 63-86.7%, respectively. Information on insecticide resistance status and resistance allele frequency reported in this study provided baseline data for management of insecticide resistance of Q-biotype B. tabaci in eastern China.