Insecticidal and repellent activities of Artemisia herba alba Asso, Juniperus phoenicea L and Rosmarinus officinalis L essential oils in synergized combinations against adults of Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)

Abstract

Using essential oil (EO) mixtures to improve their single effectiveness aids to minimize insect resistance to synthetic insecticides and reduce the amounts of the applied bio-products. This study seeks to identify the chemical compositions of nine binary combinations of EOs of Artemisia herba alba Asso (A), Juniperus phoenicea L (B), and Rosmarinus officinalis L (C), by Gas Chromatography coupled to Mass Spectrometry (GC-MS) side to side with the evaluation of their toxicity and repellency effectiveness against adults of Tribolium castaneum Herbst by fumigation and repellent tests. GC-MS results revealed that each mixture was dominated by one of the following compounds: Car-3-en-5-one, α-pinene, exo-2,7,7-trimethylbicyclo[2.2.1]heptan-, and Camphor. After 24 h of treatment, the most toxic mixtures were H (3C:1A), L (1B:1C), with K (1B:3C) (LD50 = 64.99, 68.98, and 74.76 μL/L air, respectively). After 96 h, synergistic mixtures K, I (1C:1A), and L seemed to be the most potent (LD50 = 55.6, 57.63, and 58.46 μL/L air, respectively) throughout the period of treatment. LT90 values at the concentration of 83.66 μL/L air did not exceed the limit of 19.20 h for the less potent blend. The most repellent mixtures were F, D, E, and H, showing RD90 values of 1.25, 2.99, 3.46, and 3.83 nL/cm2, respectively. All samples showed synergistic effects, except the combinations I and G (1C:3A). The synergistic mixtures might be suitable as alternatives to chemical treatments for the control of T. castaneum, but tests at a larger scale are necessary to confirm our results.