The Tunisian Artemisia Essential Oil for Reducing Contamination of Stored Cereals by Tribolium castaneum.

Essential oils of three species of Artemisia genus (A. absinthium L., A. campestris L. and A. herba-alba (Asso)) were analyzed by gas chromatography-mass spectrometry (GC-MS) and their potential insecticidal and repellent activities against the stored grain insect Tribolium castaneum (Herbst) was investigated. Fumigant and repellent activity bioassays were investigated in vitro. Chemical characterisation of essential oils showed that the bicyclic monoterpenes were predominant in all Artemisia essential oils, A. absinthium essential oil having the highest content of bicyclic monoterpenes, bicycloheptanes, naphthalenes and cycloalkenes. A. campestris had the highest content of sesquiterpenoids and acyclic monoterpenoids. A. herba-alba was characterised by the highest amounts of menthane monoterpenoids, oxanes, cumenes, oxolanes, ketones, benzenoids and monocyclic monoterpenes. Fumigant bioassay demonstrated that the three types of oil applied separately caused significant insect mortality. The lowest median lethal dose, LC50=142.8 μL/L, was observed with A. herba-alba. In repellency test, essential oil of A. absinthium was more potent with more rapid action than all other species. The mixture of Artemisia sp. essential oils showed an antagonistic effect in all the tested combinations. This study highlighted an important potential of Artemisia sp. especially A. herba-alba and A. absinthium in the control of the pests of stored products.