Water-distilled essential oil from the dried bulbs of Allium chinense (Liliaceae) was analyzed by gas chromatography–mass spectrometry (GC–MS). Eighteen compounds, accounting for 98.4% of the total oil, were identified and the main components of the essential oil of A. chinense were methyl allyl trisulfide (30.7%), dimethyl trisulfide (24.1%), methyl propyl disulfide (12.8%) and dimethyl disulfide (9.6%) followed by methyl allyl disulfide (3.4%) and methyl propyl trisulfide (3.6%). The essential oil exhibited contact toxicity against the booklice ( Liposcelis bostrychophila ) with an LC 50 value of 441.8 μg/cm 2 while the two major constituents, dimethyl trisulfide and methyl propyl disulfide had LC 50 values of 153.0 μg/cm 2 and 738.0 μg/cm 2 against the booklice, respectively. The essential oil of A. chinense possessed strong fumigant toxicity against the booklice with an LC 50 value of 186.5 μg/l while methyl allyl trisulfide (LC 50 = 90.4 μg/l) and dimethyl trisulfide (LC 50 = 114.2 μg/l) exhibited stronger fumigant toxicity than methyl propyl disulfide (LC 50 = 243.4 μg/l) and dimethyl disulfide (LC 50 = 340.8 μg/l) against the booklice. The results indicated that the essential oil and its major constituents have potential for development into natural insecticides or fumigants for control of insects in stored grains.
In our screening program for new agrochemicals from wild plants and Chinese medicinal herbs, Teucrium quadrifarium aerial parts at flowering stage was found to possess strong insecticidal activity against booklice (Liposcelis bostrychophila). Water-distilled essential oil from T. quadrifarium aerial parts was analyzed by gas chromatography-mass spectrometry (GC-MS). Fourty-seven components comprising 97.2 % of the total oil were identified and the main components of the essential oil were germacrene D (8.8 %), linalool (8.2 %), camphene (7.8 %), β-caryophyllene (7.3 %), β-cadinene (6.8 %), 1,8-cineole (6.5 %), 4-terpineol (5.8 %), and α-terpineol (5.1 %). The essential oil of T. quadrifarium possessed contact toxicity against L. bostrychophila with a LC50 value of 95.1 μg/cm2. The oil also showed fumigant toxicity against L. bostrychophila with a LC50 value of 222.0 μg/l. These findings suggested that the essential oil of T. quadrifarium aerial parts has potential to be developed as new natural insecticides for the control of grain storage insects.
危险品化学品经营许可证（带存储）