Evaluation of insecticidal activity of Nardostachys jatamansi essential oil against some grain storage insects
Xin Chao Liu and Zhi Long Liu
Water-distilled essential oil from Nardostachys jatamansi (Caprifoliaceae) roots was analyzed by gas chromatography-mass spectrometry (GC-MS). Twenty-nine compounds, accounting for 98.1% of the total oil, were identified. The main components of the essential oil of N. jatamansi were calerene (25.9%), patchouol (10.6%), α-gurjunene (7.5%), aristolone (7.1%) and β-maaliene (6.5%) followed by spathulenol (4.3%). The essential oil had higher sesquiternoids content (85.4%) than monoterpenoids (8.5%). It exhibited contact toxicity with LC50 value of 277.05 mg/cm2 and fumigant toxicity with LC50 value of 0.74 mg/l against Liposcelis bostrychophila.The oil exhibited contact toxicity against Sitophilus zeamais and Tribolium castaneum adults with LC50 values of 70.83 and 45.38 μg/adult, respectively. This oil possessed fumigant toxicity against S. zeamais and T. castaneum adults with LC50 values of 82.13 and 53.29 mg/l. The results indicate that the essential oil of N. jatamansi has potential for development into natural insecticides or fumigants for control of insects in stored grains.