Evaluation of Contact Toxicity and Repellency of the Essential Oil of Pogostemon cablin Leaves and Its Constituents Against Blattella germanica (Blattodae: Blattelidae).
The aim of this research was to evaluate contact toxicity and repellency of the essential oil of Pogostemon cablin (Blanco) Bentham leaves against German cockroaches (Blattella germanica) (L.) and to isolate any active constituents. Essential oil of P. cablin leaves was obtained by hydrodistillation and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Twenty-three components were identified in the essential oil, and the main constituents were patchoulol (41.31%), pogostone (18.06%), α-bulnesene (6.56%), caryophyllene (5.96%), and seychellene (4.32%). Bioactivity-directed chromatographic separation of the essential oil led to the isolation of pogostone, patchoulol, and caryophyllene as active compounds. The essential oil of P. cablin leaves exhibited acute toxicity against male B. germanica adults with an LC50 value of 23.45 μg per adult. The constituent compound, pogostone (LC50 = 8.51 μg per adult) showed stronger acute toxicity than patchoulol (LC50 = 207.62 μg per adult) and caryophyllene (LC50 = 339.90 μg per adult) against the male German cockroaches. The essential oil of P. cablin leaves and the three isolated constituents exhibited strong repellent activity against German cockroaches at a concentration of 5 ppm. The results indicated that the essential oil of P. cablin leaves and its major constituents have good potential as a source for natural insecticides and repellents.
Department of Entomology, China Agricultural University, 2 Yuanmingyuan West Rd., Haidian District, Beijing 100193, China. zhilongliu@cau.edu.cn.
Xin Chao
XC
Liu
State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Communicable Disease Control and Prevention, Chinese Center for Disease Control and Prevention, Beijing 102206, China.
Qiyong
Q
Liu
Department of Entomology, China Agricultural University, 2 Yuanmingyuan West Rd., Haidian District, Beijing 100193, China.
Han
H
Chen
Department of Entomology, China Agricultural University, 2 Yuanmingyuan West Rd., Haidian District, Beijing 100193, China.
Qi Zhi
QZ
Liu
Department of Entomology, China Agricultural University, 2 Yuanmingyuan West Rd., Haidian District, Beijing 100193, China.
Shi Yao
SY
Jiang
Department of Entomology, China Agricultural University, 2 Yuanmingyuan West Rd., Haidian District, Beijing 100193, China. zhilongliu@cau.edu.cn.
Zhi Long
ZL
Liu
D000818:Animals; D020048:Blattellidae / Q000187:drug effects* / Q000254:growth & development; D008401:Gas Chromatography-Mass Spectrometry; D007302:Insect Repellents / Q000494:pharmacology / Q000633:toxicity*; D007306:Insecticides / Q000494:pharmacology / Q000633:toxicity; D019686:Lamiaceae / Q000737:chemistry*; D008297:Male; D009758:Nymph / Q000187:drug effects / Q000254:growth & development; D009822:Oils, Volatile / Q000494:pharmacology / Q000633:toxicity*; D018515:Plant Leaves / Q000737:chemistry
D007302:Insect Repellents; D007306:Insecticides; D009822:Oils, Volatile
caryophyllene; patchoulol; pogostone