Chemical composition and larvicidal activity of essential oil of Lippia kituiensis against larvae of Rhipicephalus appendiculatus

  • CJ Kosgei
  • JC Matasyoh
  • CM Mwendia
  • ST Kariuki
  • AY Guliye
Keywords: Rhipicephalus appendiculatus, essential oils, acaricidal activity, ticks

Abstract

This study evaluated the larvicidal activity of essential oil of Lippia kituiensis leaves against larvae of Rhipicephalus appendiculatus. The oil was obtained by hydro-distillation of fresh leaves and analysed using Gas Chromatography-Mass Spectrometry (GC-MS). Analysis showed that sesquiterpenes were dominant (56.57%), followed by monoterpenes (36.36%), diterpenes (2.59%) and others (5.19%). Major sesquiterpenes were germacrene D, β-bourbonene, gamma cadinene and 2-isopropyl-5-methyl-9-methylene-bicycle (4.4.0)dec-1-ene. Major monoterpenes were (1S, 4S)-(-)-camphor, trans-sabinene hydrate, gamma-terpinene, dl-limonene, alpha-terpinolene, l-Phellandrene, beta-Myrcene, sabinene, camphene, alpha-pinene, 4-terpineol, 4-methyl-1-(1-methylethyl)-3-cyclohexen-1-ol, 14.29 borneol (=endo-borneol), camphore, and neo-alloocimene. At 6, 12, 24, and 48 hrs after larval treatment, the oil showed activity against R. appendiculatus larvae with LC50in mg/ml of 3.26(3.14-3.38), 3.21(3.08-3.32), 3.15(3.03-3.26), 3.09(2.97-3.20) while LC90in mg/ml were 4.15 (3.95-4.45), 4.03 (3.85-4.30), 3.94 (3.77-4.19), 3.86 (3.69-4.09) respectively. Results of one way ANOVA (Analysis of Variance) showed there was no significant difference in activity of the oil against the larvae, between 6, 12, 24 and 48 hrs in all the concentrations used P = 0.97, 95% confidence. The findings indicatedthat essential oil of L. kituiensis possessed larvicidal properties and can be used to control tick larvae.

Keywords: Rhipicephalus appendiculatus; essential oils; acaricidal activity, ticks.
Published
2015-01-16
Section
Articles

Journal Identifiers


eISSN: 1997-342X
print ISSN: 1991-8631