Abstract:
OBJECTIVE : To evaluate the insecticide, larvicidal and repellent activity of the essential oils
from Callistemon viminalis, Melaleuca leucadendron, and Hyptis suaveolens against Chrysodeixis
chalcites and to compare it with neem oil (Azadirachta indica). METHODS : The essential oils
of the leaves of these aromatiques plants were extracted by steam distillation and contacts
tests were carried out. RESULTS: Essential oils in ethanol from Callistemon viminalis showed a
higher biological activity than the neem with 100% larval mortality at the concentration of 2
μg/mL for 6 h, 100% and 90% in ethanol from Melaleuca leucadendron and Hyptis suaveolens,
respectively at the concentration of 4 μg/mL for 24 h. By inhalation, the essential oils from
Melaleuca leucadendron and of Hyptis suaveolens were more effective with mortality rates of
larvae 100% and 50% respectively at 2 μg/L air applied after 24 h. Nevertheless, the neem
has shown to be a repulsive plant and anti-nutritional plant. A significant difference in the
percentages of consumption between leaves treated with neem oil and the control samples was
observed (Newman-Keuls test) except for Melaleuca leucadendron. CONCLUSIONS : The results of
the study highlight remarkable biocide, properties of tested extracts, which provides important
opportunities for the development of biopesticides.
