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Biocidal
potential of clove oils against Aedes albopictus – A
comparative study
Sumangala K. Bhat* and Vivek Kempraj
Biotechnology Research Center, Rai Foundation, Gottigere,
Bannarghatta Road, Bangalore, Karnataka, India – 560 083.
 *Corresponding
author. E-mail:
bhat.sumangala@gmail.com. Tel : 9180-26541973. Fax:
9180-26541973.
Accepted 15 October, 2009 |
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The first phase of the study involved evaluation of leaf and
bud oils of clove, Syzygium aromaticum for their
biocidal (i.e. ovicidal and larvicidal) activity against
Aedes albopictus. Eggs and fourth instar larvae were
exposed to different concentrations of the oils to
investigate their comparative efficacy against the target
mosquito species. In the second phase of the study, biocidal
activity of ‘test formulation’ derived from the leaf oil and
commercial mosquitocide, Prallethrin were estimated by the
same method to compare the efficacy of the former with
popular mosquitocides. Mortality data were analyzed by a
computerized Log-Probit analysis (StatsDirect). Ovicidal
assay of the oil samples recorded EC50 values of
0.37 and 2.0 mg/ml respectively for leaf and bud oil.
Larvicidal assay showed LC50 and LC95
values of leaf oil as 5.3 and 7.03 mg/ml respectively, while
bud oil recorded LC50 and LC95 values
of 17.84 and 23.99 mg/ml, respectively. The ‘test
formulation’ recorded EC50 value of 1.63 mg/ml,
LC50 of 3.67 mg/ml and LC95 of 13.49
mg/ml respectively, indicating levels comparable to that of
prallethrin. Third phase of the study involved chemical
characterization of the oil samples using GC-MS. Eugenol
constituted the major component of both the oils. The study
demonstrated the potential of clove oil as a biocide against
A. albopictus and warrants further standardization of
the ‘test formulation’
Key words:
Aedes albopictus, biocide, essential oil composition,
eugenol, Syzygium aromaticum, test formulation.
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