Essential oils rich in pulegone for insecticide purpose against legume bruchus species: Case of <i>Ziziphora hispanica</i> L. and <i>Mentha pulegium</i> L.

Abstract

Ziziphora hispanica L. and Mentha pulegium L. are aromatic shrubs known to produce essential oils demanded by food industries. This study reports on the insecticidal activity of these two oils harvested in Khenifra (Morocco) and of its major compound (Pulegone) against the main legume bruchids. Chromatographic analysis revealed the presence of 33 compounds in the essential oil of Ziziphora hispanica (EOZH) and 24 compounds in the essential oil of Mentha pulegium (EOMP), with pulegone being the most dominant in both with percentages respectively of 79.1% and 63.8%. According to the insecticidal activities exerted, the two essential oils, as well as the pulegone, showed significant results against all the bruchids tested of legumes. Pulegone has shown good insecticidal activity, thus the lethal doses of 50% are between 61.6mg/g and 74.4mg/g, which explains the remarkable activity of the two essential oils which are rich in this molecule. moreover, the addition of essential oils in the storage of legumes does not have a significant effect on the legumes and does not diminish their nutritional qualities. This study indicates that essential oils and their main constituent have the potential to be developed into botanical insecticides.

Keywords

• essential oils
• pulegone
• insecticidal activities
• bruchids
• legumes