title: Chemical composition, larvicidal action, and adult repellency of Thymus magnus against Aedes albopictus.
abstract: Thymus magnus, an endemic species, is found in the Republic of Korea. The volatile compounds extracted by SPME from T. magnus were investigated for their chemical composition and electrophysiological response against the Asian tiger mosquito, Aedes albopictus. The volatile compounds of T. magnus as determined by gas chromatography mass spectrometry were gamma-terpinene (33.0%), thymol (29.9%), beta-bisabolene (8.9%), p-cymene (8.3%), alpha-terpinene (5.0%), myrcene (4.7%), beta-caryophyllene (4.0%), alpha-thujene (2.7%), camphene (1.3%), carvacrol (1.2%), and alpha-pinene (1.1%). Among these candidates, thymol exhibited complete (100%) repellent activity against female Ae. albopictus, an effect that was confirmed through evaluating the electrophysiological response on the antenna of Ae. albopictus. The effectiveness of a binary 1:2 mixture of thymol and vanillin (0.05:0.1 microl per cm2) was found to be significantly more effective than thymol alone for a period of 120 min. In addition, thymol, alpha-terpinene, and carvacrol showed high larvicidal activity against on the third-stage larvae with LC50 values of 0.9 microl per 100 ml.
authors.affiliation: Department of Plant Medicine, Chungbuk National University, Cheongju 361-763, Republic of Korea.
authors.forename: Young-Uk
authors.initials: YU
authors.lastname: Park
authors.forename: Hyun-Na
authors.initials: HN
authors.lastname: Koo
authors.forename: Gil-Hah
authors.initials: GH
authors.lastname: Kim
mesh_terms: D000328:Adult; D000330:Aedes / Q000187:drug effects*; D000818:Animals; D057506:Arthropod Antennae / Q000187:drug effects; D001681:Biological Assay; D005260:Female; D006801:Humans; D007302:Insect Repellents / Q000737:chemistry / Q000494:pharmacology*; D007306:Insecticides / Q000737:chemistry / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D010938:Plant Oils / Q000737:chemistry / Q000494:pharmacology; D056910:Republic of Korea; D013943:Thymol / Q000737:chemistry / Q000494:pharmacology; D046930:Thymus Plant / Q000737:chemistry*; D055815:Young Adult
chemical_list: D007302:Insect Repellents; D007306:Insecticides; D010936:Plant Extracts; D010938:Plant Oils; D013943:Thymol; C076730:citronella oil