title: Insecticidal toxicities of carvacrol and thymol derived from Thymus vulgaris Lin. against Pochazia shantungensis Chou &Lu., newly recorded pest.
abstract: The insecticidal toxicities of five essential oils against Pochazia shantungensis adults and nymphs, newly recorded pests, were evaluated. The LC50values of Thymus vulgaris, Ruta graveolens, Citrus aurantium, Leptospermum petersonii and Achillea millefolium oils were recorded as 57.48, 84.44, 92.58, 113.26 and 125.78 mg/L, respectively, against P. shantungensis nymphs using the leaf dipping bioassay, and 75.80, 109.86, 113.26, 145.06 and 153.74 mg/L, respectively, against P. shantungensis adults using the spray bioassay method. Regarding volatile components identified in T. vulgaris oil, the LC50values of carvacrol and thymol using the leaf dipping bioassay against P. shantungensis nymphs were 56.74 and 28.52 mg/L, respectively. The insecticidal action of T. vulgaris oil against P. shantungensis could be attributed to carvacrol and thymol. Based on the structure-toxicity relationship between thymol analogs and insecticidal toxicities against P. shantungensis nymphs similar to the LC50values against P. shantungensis adults, the LC50values of thymol, carvacrol, citral, 2-isopropylphenol, 3-isopropylphenol, and 4-isopropylphenol were 28.52, 56.74 and 89.12, 71.41, 82.49, and 111.28 mg/L, respectively. These results indicate that the insecticidal mode of action of thymol analogs may be largely attributed to the methyl functional group. Thymol analogues have promising potential as first-choice insecticides against P. shantungensis adults and nymphs.
authors.affiliation: Department of Bioenvironmental Chemistry, Chonbuk National University, Jeonju 54896, Korea.
authors.forename: Jun-Hwan
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Bioenvironmental Chemistry, Chonbuk National University, Jeonju 54896, Korea.
authors.forename: Ye-Jin
authors.initials: YJ
authors.lastname: Jeon
authors.affiliation: Department of Bioenvironmental Chemistry, Chonbuk National University, Jeonju 54896, Korea.|Division of Research Planning, National Research Institute of Health, Centers for Disease Control &Prevention, Chungbuk 28159, Korea.
authors.forename: Chi-Hoon
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Department of Biosystems and Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea.
authors.forename: Namhyun
authors.initials: N
authors.lastname: Chung
authors.affiliation: Department of Bioenvironmental Chemistry, Chonbuk National University, Jeonju 54896, Korea.
authors.forename: Hoi-Seon
authors.initials: HS
authors.lastname: Lee
mesh_terms: D000818:Animals; D000081007:Cymenes; D008401:Gas Chromatography-Mass Spectrometry; D006430:Hemiptera / Q000187:drug effects*; D007306:Insecticides / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D015394:Molecular Structure; D039821:Monoterpenes / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D009822:Oils, Volatile / Q000633:toxicity; D010938:Plant Oils / Q000633:toxicity; D013943:Thymol / Q000032:analysis / Q000737:chemistry / Q000633:toxicity*; D046930:Thymus Plant / Q000737:chemistry*; D013997:Time Factors
chemical_list: D000081007:Cymenes; D007306:Insecticides; D039821:Monoterpenes; D009822:Oils, Volatile; D010938:Plant Oils; D013943:Thymol; C073316:carvacrol