Insecticide resistance of Bemisia tabaci field populations

Resistance to 13 insecticides in field populations of Bemisia tabaci from six regions (Fuzhou, Zhangzhou, Longyan, Sanming, Nanping, Ningde) of Fujian Province, China was monitored by adult leaf-dipping bioassay. Compared with the susceptible SUD-S strain, all the six field populations exhibited high levels of resistance to lambda-cyhalothrin (838.38-2460.52 fold), fenpropathrin (244.64-834.29 fold), cypermethrin (116.02-266.35 fold), deltamethrin (81.75-124.18 fold), acephate (425.18-875.56 fold) and chlorpyrifos (54.53-78.43 fold), moderate levels of resistance to dimethoate (14.16-17.66 fold), low to moderate levels of resistance to dichlorvos (6.23-11.25 fold) and low levels of resistance to methomyl (4.07-5.66 fold), respectively. Among these six field-collected populations, only Zhangzhou population had moderate resistance to imidacloprid, acetamiprid and thiamethoxam (23.08 fold, 10.32 fold and 24.60 fold, respectively). All field strains tested displayed no resistance to abamectin.