All the compounds sited in Table 1 that were purchasedfrom SigmaAldrich(Steinheim,Germany), were in thehighest purity (>97 %) and used as standards. Citral (mixtureof neral and geranial) was also bought from Sigma-Aldrich. Particularly, the enantiomers: (+)-α-pinene (97 %),(−)-α-pinene (99 %), (+)-β-pinene (98.5 %), (−)-β-pinene(99 %), R-(+)-limonene (96 %), and S-(−)-limonene (95 %)were purchased from Fluka (Steinheim, Germany). DEETwas kindly provided by Bayer CropScience