Abstract

AUTECOLOGY AND INSECTICIDAL POTENTIAL OF MENTHA LONGIFOLIA FROM MADINAH EL MONAWARA

Amal Ahmed Mohammed Al-Ghamdi*

ABSTRACT

Mentha plants are grown in abundance in Al-Madina. Their potentials in the medicine and aromatic industry are widely studied. Soil physicochemical studies were carried out to determine the best condition for the growth of Mentha longifolia L., while GC-MS analysis were carried out to isolate and identify the essential oils in the leaves and then further tested on the Tribolium castaneum to investigate repellency properties. M. longifolia were found to grow well in neutral soil that contains high percentage of organic matter (OM). The plants also grew on soil that recorded very low amounts of heavy metals. Some secondary metabolites (e.g. cathechin, epicathechin, gallochatechin and myricetin-3-glucoside) were isolated and identified from the leaves of Mentha longifolia L. and the extracted phytochemicals were then assessed for their insecticidal activity. Only cathechin, epicathechin and gallochatechin successfully repelled the T. castaneum which showed more than 70% repellency activity. Further investigation is necessary to assess the suitability of M. longifolia in repelling stored product insect pests.

Keywords: Mentha longifolia. physicochemical. secondary metabolites. Repellant. Tribolium castaneum.