The larval mortality bioassays were carried out according tothe test method of larval susceptibility assuggested by theWorld Health Organization (WHO 2005) with modifications. Sufficient amounts of each compound were transferred to a vial, and the residual solvent was removed under high vacuum.Stock solutions of 10 % (w/v) in dimethyl sulfoxide(DMSO) were prepared for each testing material. Twenty latethird- to early fourth-instar mosquito larvae were placed in 2 % (v/v) aqueous solution of DMSO (98 ml of tap water plus2 ml of DMSO), followed by addition of the tested material solution. Gentle shaking to ensure a homogeneous test solution was then performed. Four replicates per dose were made and a treatment with 98 ml of tap water and 2 ml of DMSOwas included in each bioassay as control. The larvicidal toxicity of EOs from the three Citrus plants (C. sinensis, C. limon,and C. paradisi) and eight of their components (namely, RandS-enantiomers of limonene, enantiomers of α- and β-pinenes, citral, and γ-terpinene) were examined.