The residual contact toxicity of three benzofuranoids (Z)-butylidenephthalide (1), (3S)-butylphthalide (2), and (Z)-ligustilide (3) identified in the rhizome of Cnidium officinale (Apiaceae) to B- and Q-biotype females of Bemisia tabaci was evaluated using a leaf-dip bioassay. Results were compared