Journal of Animal and Plant Sciences
J. Anim. Plant Sci. [ISSN 2071 - 7024]
Volume 19(1): 2854 - 2863. Published August, 2013.
Chemical compositions and residue activities of Ocimum canum Sims and Ocimum basilicum L essential oils on adult female Anopheles funestus ss
Philippe Belong 1, Patrick Akono Ntonga* 2, Eric- Moïse Bakwo Fils 3, Gisèle Aurelie Foko Dadji 4, Joseph Lebel Tamesse 5.
1, 4, 5 Higher Teacher training college, University of Yaoundé I., Cameroon
2 Laboratory of Animal Biology, Department of Animal Biology,
Faculty of Science, University of Douala, P.O. Box: 2701 Douala,
Cameroon.
3 Teacher Training College, University of Maroua, Cameroon.
* Corresponding author: Laboratory of Animal Biology, Department of
Animal Biology, Faculty of Science, University of Douala, P.O. Box 2701
Douala, Cameroon. patakono2000@yahoo.fr. Tel. +237 77 74 56 54.
Key-words: Anopheles funestus ss, Ocimum canum Sims, Ocimum basilicum L. Essential oils, Residue, Adulticide.
1 SUMMARY
The essential oils obtained by hydrodistillation of the
leaves of Ocimum canum (Camphor basil) and Ocimum basilicum (Sweet
basil) were analyzed and their residual activity on adult Anopheles
funestus ss determined. The extraction yields showed that the leaves of
Ocimum canum are four times richer in essential oil (0.44%) than those
of Ocimum basilicum (0.11%). Analysis by (GC) and (GC / MS) revealed
that these oils are monoterpenic (83.4 to 92.4%). The oxygenated
monoterpenes are predominant in the essential oil of Ocimum canum (63,
3%), while the monoterpene hydrocarbons are mainly in essential oil of
Ocimum basilicum (56.2%). The major components identified in essential
oil of O. canum are linalool (53.8%) and limonene (22.2%). The
essential oil of O. basilicum is distinguished by the predominance of
compounds such as linalool (18.9%), limonene (30.9%) and β-phellandrene
(15.3%). Bioassay tests done by the World Health Organization standard
protocol revealed that these essential oils have remarkable adulticidal
properties on An. funestus ss. The essential oil of O. canum (LC50 =
45.61 ppm, one hour after exposure piece of nets to product) is the
most efficient, followed by the essential oil of O. basilicum (LC50 =
84ppm). Besides, these studies have shown that the effectiveness of
these species decreases significantly with time (LC50 for O. canum =
45.61, 62.53, 311.23 respectively one hour, five days and 10 days after
exposure piece of nets to the product. LC50 for O. basilicum = 84;
171.7, 397respectively one hour, 5 days and 10 days after exposure
piece of nets to the product). This result explains the low residue
activity of these species on adult females of An. funestus. This low
residue would be the fact of the highly volatile molecules of these
species, and allows guiding insecticidal use of these essential oils in
the form of aerosol bombs.
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