Contact Toxicity of an Essential Oil from <i>Acorus calamus</i> (Acoraceae) Rhizomes against <i>Tetranychus urticae</i> and <i>Tetranychus macfarlanei</i> (Acari: Tetranychidae) and <i>Amblyseius longispinosus</i> (Acari: Phytoseiidae)1

The contact toxicity activity of an essential oil extracted from Acorus calamus (L.) (Acoraceae) was evaluated against the phytophagous spider mites Tetranychus urticae Koch and macfarlanei Baker & Pritchard (Acari: Tetranychidae) predatory mite Amblyseius longispinosus (Evans) Phytoseiidae). Adult mortality 24 h following application 5% (v/v) concentration exceeded 90% for T. macfarlanei. Application 1.2–5% concentrations to eggs reduced egg viability, with 0–54% hatch 0% 6 d treatment. At 2.5%, toxic A. longipinosus by residual (58% mortality) direct (0% mortality). No 47.6 were oviposited toxicity, respectively. chemical constituents oil, as determined gas chromatography–mass spectrometry, showed that camphor (41.07%) 5,5-dimethyl-2-ethynylcyclopent-2-en-1-ol (27.96%) major compounds oil. These results indicate this fresh rhizomes could prove useful in controlling Our findings also had no deleterious effects test; however, consuming treated negatively impacted.