Abstract:In order to clarify the resistance status of strawberry Tetranychus urticae to common acaricides in Jiangsu Province,we monitored the resistance level of T. urticae collected from Lishui,Qixia,Gaochun and Jiangning in Nanjing city,Baitu in Zhenjiang city,Taixing in Taizhou city,Jiaze in Changzhou city and Yanzhuang in Xuzhou city to five acaricides using a leaf-dip bioassay.The results showed that most of the field populations in 8 regions were sensitive to four acaricides,including cyetpyrafen 30% SC,bifenazate 43% SC,cyenopyrafen 30% SC and cyflumetofen 20% SC(RR = 5.045 - 36.267),and some were in low
to moderate level of resistance.Only Jiangning population had high resistance to bifenazate 43% SC(RR = 62.605).However,all the field populations had resistance to avermectin 3% ME,and the resistance ratio ranged from 6.599 to 340.995,which was at a low to very high level of resistance.There were significant regional differences in the resistance levels of different acaricides.In the control of strawberry T. urticae, attention should be paid to the rotation of insecticides according to the local background of insecticide use,to the development of insecticide resistance.