Chemical Composition and Insecticidal Activities of Essential Oils of Myrtaceae against Tribolium castaneum (Coleoptera: Tenebrionidae)

The present study was designed to determine chemical composition of essential oils extracted from different species of the Myrtaceae family and to evaluate their insecticidal activities against Tribolium castaneum (Coleoptera: Tenebrionidae). The essential oils of 10 species were extracted by hydrodistillation and analyzed by a gas chromatography-flame ionization detector (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The main component of Eucalyptus crebra, E. microtheca, E. rudis and Melaleuca quinquenervia essential oils was 1,8-cineole (31.6-49.7%). E. melanophloia and E. tereticornis contained p-cymene (41.8-58.1%) as a major component, while Eucalyptus kitsoniana and E. pruinosa essential oils were dominated by alpha-pinene (25.8-31.4%). Eugenol methyl ether was identified as a major component in M. bracteata essential oil (82.3%). a-Pinene (31.4%) was the main component in the C. viminalis essential oil. Essential oils of all selected plant species showed good insecticidal activities against T. castaneum when compared with pyrethroid as a positive control. Eucalyptus rudis proved most potent against T. castaneum, followed by M. bracteata, M quinquenervia, and C. viminalis. The results of this study indicate that essential oil of Myrtaceae leaves have potential to be used in the control of T. castaneum.